18th European Symposium on Radiopharmacy and Radiopharmaceuticals

Table of contents OP03 Selective extraction of medically-related radionuclides from proton-irradiated thorium targets V. Radchenko, J.W. Engle, C. Roy, J. Griswold, M.F. Nortier, E.R. Birnbaum, M. Brugh, S. Mirzadeh, K. D. John, M.E. Fassbender OP04 Comparison of [68Ga]FSC(succ-RGD)3 and [68Ga]NODAGA-RGD for PET imaging of αvβ3 integrin expression Chuangyan Zhai, Gerben M. Franssen, Milos Petrik, Peter Laverman, Clemens Decristoforo OP05 A new NPY-Y1R targeting peptide for breast cancer PET imaging Ait-Mohand Samia, Dumulon-Perreault Véronique, Guérin Brigitte OP06 The influence of multivalency on CCK 2 receptor targeting D. Summer, A. Kroess, C. Rangger, H. Haas, P. Laverman, F. Gerben, E. von Guggenberg, C.Decristoforo OP07 SPECT Imaging of αvβ3 Expression by [99mTc(N)PNP43]- Bifunctional Chimeric RGD Peptide not Cross-Reacting with αvβ5 Cristina Bolzati, Nicola Salvarese, Fiorenzo Refosco, Laura Meléndez-Alafort, Debora Carpanese, Antonio Rosato, Michele Saviano, Annarita Del Gatto, Daniela Comegna, Laura Zaccaro OP09 New dienophiles for the inverse-electron-demand Diels-Alder reaction and for pretargeted PET imaging Emilie Billaud, Muneer Ahamed, Frederik Cleeren, Elnaz Shahbazali, Tim Noël, Volker Hessel, Alfons Verbruggen and Guy Bormans OP10 New complexing agent for Al18F-labelling of heat-sensitive biomolecules: Synthesis and preclinical evaluation of Al18F-RESCA1-HAS Cleeren F, Lecina J, Koole M, Verbruggen A and Bormans G OP11 A novel versatile precursor efficient for F-18 radiolabelling via click-chemistry B. Lugatoa, S. Stucchia, E.A. Turollaa, L. Giulianoa, S.Toddea, P. Ferraboschib OP12 A general applicable method to quantify unidentified UV impurities in radiopharmaceuticals R.P. Klok, M.P.J. Mooijer, N.H. Hendrikse, A.D. Windhorst OP13 Development of [18F]Fluoro-C-glycosides to radiolabel peptides Collet C., Petry N., Chrétien F., Karcher G., Pellegrini-Moïse N., Lamandé-Langle S. OP14 A Microfluidic Approach for the 68Ga-labeling of PSMAHBED-CC and NODAGA-RGD Sarah Pfaff, Cecile Philippe, Markus Mitterhauser, Marcus Hacker, Wolfgang Wadsak OP16 Surprising reactivity of astatine in the nucleophilic substitution of aryliodonium salts: application to the radiolabeling of antibodies François Guérard, Yong-Sok Lee, Sébastien Gouard, Kwamena Baidoo, Cyrille Alliot, Michel Chérel, Martin W. Brechbiel, Jean-François Gestin OP17 64Cu-NOTA-pertuzumab F(ab')2 fragments, a second-generation probe for PET imaging of the response of HER2-positive breast cancer to trastuzumab (Herceptin) Lam K, Chan C, Reilly RM OP18 Development of radiohalogenated analogues of a avb6-specific peptide for high LET particle emitter targeted radionuclide therapy of cancer Salomé Paillas, John Marshall, Jean-Pierre Pouget, Jane Sosabowski OP19 Ligand Specific Efficiency (LSE) as a guide in tracer optimization Emmanuelle Briard, Yves P. Auberson, John Reilly, Mark Healy, David Sykes OP23 The radiosynthesis of an 18F-labeled triglyceride, developed to visualize and quantify brown adipose tissue activity Andreas Paulus, Wouter van Marken Lichtenbelt,Felix Mottaghy, Matthias Bauwens OP24 Influence of the fluorescent dye on the tumor targeting properties of dual-labeled HBED-CC based PSMA inhibitors Baranski, Ann-Christin, Schäfer, Martin, Bauder-Wüst, Ulrike, Haberkorn, Uwe, Eder, Matthias, Kopka, Klaus OP25 [18F]MEL050 as a melanin PET tracer : fully automated radiosynthesis and evaluation for the detection of pigmented melanoma in mice pulmonary metastases Chaussard M, Hosten B, Vignal N, Tsoupko-Sitnikov V, Hernio N, Hontonnou F, Merlet P, Poyet JL, Sarda-Mantel L, Rizzo-Padoin N OP26 Design and Preclinical Evaluation of Novel Radiofluorinated PSMA Targeting Ligands Based on PSMA-617 J. Cardinale, M. Schäfer, M. Benešová, U. Bauder-Wüst, O. Seibert, F. Giesel, U. Haberkorn, M. Eder, K. Kopka OP27 A novel radiolabeled peptide for PET imaging of prostate cancer: 64Cu-DOTHA2-PEG-RM26 Mansour Nematallah, Paquette Michel, Ait-Mohand Samia, Dumulon-Perreault Véronique, Lecomte Roger, Guérin Brigitte OP29 Biodistribution of [18F]Amylovis®, a new radiotracer PET imaging of β-amyloid plaques Fernandez-Maza L, Rivera-Marrero S, Prats Capote A, Parrado-Gallego A, Fernandez-Gomez I, Balcerzyk M, Sablon-Carrazana M, Perera-Pintado A, Merceron-Martinez D, Acosta-Medina E, Rodriguez-Tanty C OP30 Synthesis and preclinical evaluation of [11C]-BA1 PET tracer for the imaging of CSF-1R Bala Attili, Muneer Ahamed, Guy Bormans OP31 In vivo imaging of the MCHR1 in the ventricular system via [18F]FE@SNAP C. Philippe, M. Zeilinger, T. Scherer, C. Fürnsinn, M. Dumanic, W. Wadsak, M. Hacker, M. Mitterhauser OP32 Synthesis of the first carbon-11 labelled P2Y12 receptor antagonist for imaging the anti-inflammatory phenotype of activated microglia B. Janssen, D.J. Vugts, G.T. Molenaar, U. Funke, P.S. Kruijer, F. Dollé, G. Bormans, A.A. Lammertsma, A.D. Windhorst OP33 Radiosynthesis of a selective HDAC6 inhibitor [11C]KB631 and in vitro and ex vivo evaluation Koen Vermeulen, Muneer Ahamed, Michael Schnekenburger, Mathy Froeyen, Dag Erlend Olberg, Marc Diederich, Guy Bormansa OP34 Improving metabolic stability of fluorine-18 labelled verapamil analogues Raaphorst RM, Luurtsema G, Lammertsma AA, Elsinga PH, Windhorst AD OP36 Development of a novel PET tracer for the activin receptor-like kinase 5 Lonneke Rotteveel, Uta Funke, Peter ten Dijke, Harm Jan Bogaard, Adriaan A. Lammertsma, Albert D. Windhorst OP37 SPECT imaging and biodistribution studies of 111In-EGF-Au-PEG nanoparticles in vivo Lei Song, Sarah Able, Nadia Falzone, Veerle Kersemans, Katherine Vallis OP38 Melanoma targeting with [99mTc(N)(PNP3)]-labeled NAPamide derivatives: preliminary pharmacological studies Davide Carta, Nicola Salvarese, Wiebke Sihver, Feng Gao, Hans Jürgen Pietzsch, Barbara Biondi, Paolo Ruzza, Fiorenzo Refosco, Cristina Bolzati OP39 [68Ga]NODAGA-RGD: cGMP synthesis and data from a phase I clinical study Roland Haubner, Armin Finkensted, Armin Stegmair, Christine Rangger, Clemens Decristoforo, Heinz Zoller, Irene J. Virgolin OP44 Implementation of a GMP-grade radiopharmacy facility in Maastricht Ivo Pooters, Maartje Lotz, Roel Wierts, Felix Mottaghy, Matthias Bauwens OP45 Setting up a GMP production of a new radiopharmaceutical Forsback, Sarita, Bergman Jörgen, Kivelä Riikka OP48 In vitro and in vivo evaluation of 68-gallium labeled Fe3O4-DPD nanoparticles as potential PET/MRI imaging agents M. Karageorgou, M. Radović, C. Tsoukalas, B. Antic, M. Gazouli, M. Paravatou-Petsotas, S. Xanthopouls, M. Calamiotou, D. Stamopoulos, S. Vranješ-Durić, P. Bouziotis OP49 Fast PET imaging of inflammation using 68Ga-citrate with Fe-containing salts of hydroxy acids A. S. Lunev, A. A. Larenkov, K.A. Petrosova, O. E. Klementyeva, G. E. Kodina PP01 Installation and validation of 11C-methionine synthesis Kvernenes, O.H., Adamsen, T.C.H. PP02 Fully automated synthesis of 68Ga-labelled peptides using the IBA Synthera® and Synthera® Extension modules René Martin, Sebastian Weidlich, Anna-Maria Zerges, Cristiana Gameiro, Neva Lazarova, Marco Müllera PP03 GMP compliant production of 15O-labeled water using IBA 18 MeV proton cyclotron Gert Luurtsema, Michèl de Vries, Michel Ghyoot, Gina van der Woude, Rolf Zijlma, Rudi Dierckx, Hendrikus H. Boersma, Philip H. Elsinga PP04 In vitro Nuclear Imaging Potential of New Subphthalocyanine and Zinc Phthalocyanine Fatma Yurt Lambrecht, Ozge Er, Mine Ince, Cıgır Biray Avci, Cumhur Gunduz, Fatma Aslihan Sarı PP05 Synthesis, Photodynamic Therapy Efficacy and Nuclear Imaging Potential of Zinc Phthalocyanines Kasim Ocakoglu, Ozge Er, Onur Alp Ersoz, Fatma Yurt Lambrecht, Mine Ince, Cagla Kayabasi, Cumhur Gunduz PP06 Radio-U(H)PLC – the Search on the Optimal Flow Cell for the γ-Detector Torsten Kniess, Sebastian Meister, Steffen Fischer, Jörg Steinbach PP07 Radiolabeling, characterization & biodistribution study of cysteine and its derivatives with Tc99m Rabia Ashfaq, Saeed Iqbal, Atiq-ur-Rehman, Irfan ullah Khan PP08 Radiolabelling of poly (lactic-co.glycolic acid) (PLGA) nanoparticles with 99mTC R Iglesias-Jerez, Cayero-Otero, L. Martín-Banderas, A. Perera-Pintado, I. Borrego-Dorado PP09 Development of [18F]PD-410 as a non-peptidic PET radiotracer for gastrin releasing peptide receptors Ines Farinha-Antunes, Chantal Kwizera, Enza Lacivita, Ermelinda Lucente, Mauro Niso, Paola De Giorgio, Roberto Perrone, Nicola A. Colabufo, Philip H. Elsinga, Marcello Leopoldo PP10 An improved nucleophilic synthesis of 2-(3,4-dimethoxyphenyl)-6-(2-[18F]fluoroethoxy) benzothiazole ([18F]FEDMBT), potential diagnostic agent for breast cancer imaging by PET V.V. Vaulina, O.S. Fedorova, V.V. Orlovskaja, С.L. Chen, G.Y. Li, F.C. Meng, R.S. Liu, H.E. Wang, R.N. Krasikova PP11 Internal radiation dose assessment of radiopharmaceuticals prepared with accelerator-produced 99mTc Laura Meléndez-Alafort, Mohamed Abozeid, Guillermina Ferro-Flores, Anna Negri, Michele Bello, Nikolay Uzunov, Martha Paiusco, Juan Esposito, Antonio Rosato PP12 A specialized five-compartmental model software for pharmacokinetic parameters calculation Laura Meléndez-Alafort, Cristina Bolzati, Guillermina Ferro-Flores, Nicola Salvarese, Debora Carpanese, Mohamed Abozeid, Antonio Rosato, Nikolay Uzunov PP13 Molecular imaging of the pharmacokinetic behavior of low molecular weight 18F-labeled PEtOx in comparison to 89Zr-labeled PEtOx Palmieri L, Verbrugghen T, Glassner M, Hoogenboom R, Staelens S, Wyffels L PP14 Towards nucleophilic synthesis of the α-[18F]fluoropropyl-L-dihydroxyphenylalanine V. V. Orlovskaja, O. F. Kuznetsova, O. S. Fedorova, V. I. Maleev, Yu. N. Belokon, A. Geolchanyan, A. S. Saghyan, L. Mu, R. Schibli, S. M. Ametamey, R. N. Krasikova PP15 A convenient one-pot synthesis of [18F]clofarabine Revunov, Evgeny, Malmquist, Jonas, Johnström, Peter, Van Valkenburgh, Juno, Steele, Dalton, Halldin, Christer, Schou, Magnus PP16 BODIPY-estradiol conjugates as multi-modality tumor imaging agents Samira Osati,Michel Paquette,Simon Beaudoin,Hasrat Ali,Brigitte Guerin, Jeffrey V. Leyton, Johan E. van Lier PP17 Easy and high yielding synthesis of 68Ga-labelled HBED-PSMA and DOTA-PSMA by using a Modular-Lab Eazy automatic synthesizer Di Iorio V, Iori M, Donati C, Lanzetta V, Capponi PC, Rubagotti S, Dreger T, Kunkel F, Asti M PP18 Synthesis and evaluation of fusarinine C-based octadentate bifunctional chelators for zirconium-89 labelling Chuangyan Zhai, Christine Rangger, Dominik Summer, Hubertus Haas, Clemens Decristoforo PP19 Fully automated production of [18F]NaF using a re-configuring FDG synthesis module. Suphansa Kijprayoon, Ananya Ruangma, Suthatip Ngokpol, Samart Tuamputsha PP20 Extension of the Carbon-11 Small Labeling Agents Toolbox and Conjugate Addition Ulrike Filp, Anna Pees, Carlotta Taddei, Aleksandra Pekošak, Antony D. Gee, Alex J. Poot, Albert D. Windhorst PP21 In vitro studies on BBB penetration of pramipexole encapsulated theranostic liposomes for the therapy of Parkinson’s disease Mine Silindir Gunay, A. Yekta Ozer, Suna Erdogan, Ipek Baysal, Denis Guilloteau, Sylvie Chalon PP22 Factors affecting tumor uptake of 99mTc-HYNIC-VEGF165 Filippo Galli, Marco Artico, Samanta Taurone, Enrica Bianchi, Bruce D. Weintraub, Mariusz Skudlinski, Alberto Signore PP23 Rhenium-188: a suitable radioisotope for targeted radiotherapy Nicolas Lepareur, Nicolas Noiret, François Hindré, Franck Lacœuille, Eric Benoist, Etienne Garin PP24 Preparation of a broad palette of 68Ga radiopharmaceuticals for clinical applications Trejo-Ballado F, Zamora-Romo E, Manrique-Arias JC, Gama-Romero HM, Contreras-Castañon G, Tecuapetla-Chantes RG, Avila-Rodriguez MA PP25 68Ga-peptide preparation with the use of two 68Ge/68Ga-generators H. Kvaternik, D. Hausberger, C. Zink, B. Rumpf, R. M. Aigner PP26 Assay of HEPES in 68Ga-peptides by HPLC H. Kvaternik, D. Hausberger, B. Rumpf, R. M. Aigner PP27 Preparation, in vitro and in vivo evaluation of a 99mTc(I)-Diethyl Ester (S,S)-Ethylenediamine- N,N´-DI-2-(3-Cyclohexyl) Propionic acid as a target-specific radiopharmaceutical Drina Janković, Mladen Lakić, Aleksandar Savić, Slavica Ristić, Nadežda Nikolić, Aleksandar Vukadinović, Tibor J. Sabo, Sanja Vranješ-Đurić PP28 90Y-labeled magnetite nanoparticles for possible application in cancer therapy S. Vranješ-Đurić, M. Radović, D. Janković, N. Nikolić, G. F. Goya, P. Calatayud, V. Spasojević, B. Antić PP29 Simplified automation of the GMP production of 68Ga-labelled peptides David Goblet, Cristiana Gameiro, Neva Lazarova PP30 Combining commercial production of multi-products in a GMP environment with Clinical & R&D activities Cristiana Gameiro, Ian Oxley, Antero Abrunhosa, Vasko Kramer, Maria Vosjan, Arnold Spaans PP31 99mTc(CO)3-labeling and Comparative In-Vivo Evaluation of Two Clicked cRGDfK Peptide Derivatives Kusum Vats, Drishty Satpati, Haladhar D Sarma, Sharmila Banerjee PP32 Application of AnaLig resin for 99mTc separation from molybdenum excess Wojdowska W., Pawlak D.W., Parus L. J., Garnuszek P., Mikołajczak R. PP33 Constraints for selection of suitable precursor for one-step automated synthesis of [18F]FECNT, the dopamine transporter ligand Pijarowska-Kruszyna J, Jaron A, Kachniarz A, Malkowski B, Garnuszek P, Mikolajczak R PP34 Gamma scintigraphy studies with 99mTc- amoxicillin sodium in bacterially infected and sterile inflamed rats Derya Ilem-Ozdemir, Oya Caglayan-Orumlu, Makbule Asikoglu PP35 Preparation of 99mTc- Amoxicillin Sodium Lyophilized Kit Derya Ilem-Ozdemir, Oya Caglayan-Orumlu, Makbule Asikoglu PP36 Outfits of Tracerlan FXC-PRO for 11C-Labeling Arponen Eveliina, Helin Semi, Saarinen Timo, Vauhkala Simo, Kokkomäki Esa, Lehikoinen Pertti PP37 Microfluidic synthesis of ω-[18F]fluoro-1-alkynes Mariarosaria De Simone, Giancarlo Pascali, Ludovica Carzoli, Mauro Quaglierini, Mauro Telleschi, Piero A. Salvadori PP38 Automated 18F-flumazenil production using chemically resistant disposable cassettes Phoebe Lam, Martina Aistleitner, Reinhard Eichinger, Christoph Artner PP39 The effect of the eluent solutions (TBAHCO3, Kryptand K2.2.2) on the radiochemical yields of 18F-Fluoromethylcholine Surendra Nakka, Hemantha Kumara MC, Al-Qahtani Mohammed PP40 [68Ga]Radiolabeling of short peptide that has a PET imaging potentials Al-Qahtani, Mohammed, Al-Malki, Yousif PP41 Is validation of radiochemical purity analysis in a public hospital in a developing country possible? N Mambilima, SM Rubow PP42 Improved automated radiosynthesis of [18F]FEPPA N. Berroterán-Infante, M. Hacker, M. Mitterhauser, W. Wadsak PP43 Synthesis and initial evaluation of Al18F-RESCA1-TATE for somatostatin receptor imaging with PET Uta Funke, Frederik Cleeren, Joan Lecina, Rodrigo Gallardo, Alfons M. Verbruggen, Guy Bormans PP44 Radiolabeling and SPECT/CT imaging of different polymer-decorated zein nanoparticles for oral administration Rocío Ramos-Membrive, Ana Brotons, Gemma Quincoces, Laura Inchaurraga, Inés Luis de Redín, Verónica Morán, Berta García-García, Juan Manuel Irache, Iván Peñuelas PP45 An analysis of the quality of 68Ga-DOTANOC radiolabelling over a 3 year period Trabelsi, M., Cooper M.S. PP46 In vivo biodistribution of adult human mesenchymal stem cells I (MSCS-ah) labeled with 99MTC-HMPAO administered via intravenous and intra-articular in animal model. Preliminary results Alejandra Abella, Teodomiro Fuente, Antonio Jesús Montellano, Teresa Martínez, Ruben Rabadan, Luis Meseguer-Olmo PP47 Synthesis of [18F]F-exendin-4 with high specific activity Lehtiniemi P, Yim C, Mikkola K, Nuutila P, Solin O PP48 Experimental radionuclide therapy with 177Lu-labelled cyclic minigastrin and human dosimetry estimations von Guggenberg E, Rangger C, Mair C, Balogh L, Pöstényi Z, Pawlak D, Mikołajczak R PP49 Synthesis of radiopharmaceuticals for cell radiolabelling using anion exchange column Socan A, Kolenc Peitl P, Krošelj M, Rangger C, Decristoforo C PP50 [68Ga]peptide production on commercial synthesiser mAIO Collet C., Remy S., Didier R,Vergote T.,Karcher G., Véran N. PP51 Dry kit formulation for efficient radiolabeling of 68Ga-PSMA D. Pawlak, M. Maurin, P. Garnuszek, U. Karczmarczyk, R. Mikołajczak PP52 Development of an experimental method using Cs-131 to evaluate radiobiological effects of internalized Auger-electron emitters Pil Fredericia, Gregory Severin, Torsten Groesser, Ulli Köster, Mikael Jensen PP53 Preclinical comparative evaluation of NOTA/NODAGA/DOTA CYCLO-RGD peptides labelled with Ga-68 R. Leonte, F. D. Puicea, A. Raicu, E. A. Min, R. Serban, G. Manda, D. Niculae PP54 Synthesizer- and Kit-based preparation of prostate cancer imaging agent 68Ga-RM2 Marion Zerna, Hanno Schieferstein, Andre Müller, Mathias Berndt PP55 Synthesis of pancreatic beta cell-specific [18F]fluoro-exendin-4 via strain-promoted aza-dibenzocyclooctyne/azide cycloaddition Cheng-Bin Yim, Kirsi Mikkola, Pirjo Nuutila, Olof Solin PP56 Automated systems for radiopharmacy D. Seifert, J. Ráliš, O. Lebeda PP57 Simple, suitable for everyday routine use quality control method to assess radionuclidic purity of cyclotron-produced 99mTc Svetlana V. Selivanova, Helena Senta, Éric Lavallée, Lyne Caouette, Éric Turcotte, Roger Lecomte PP58 Effective dose estimation using Monte Carlo simulation for patients undergoing radioiodine therapy Marina Zdraveska Kochovska, Emilija Janjevik Ivanovska, Vesna Spasic Jokic PP59 Chemical analysis of the rituximab radioimmunoconjugates in lyophilized formulations intended for oncological applications Darinka Gjorgieva Ackova, Katarina Smilkov, Petre Makreski, Trajče Stafilov, Emilija Janevik-Ivanovska PP61 The need and benefits of established radiopharmacy in developing African countries Aschalew Alemu, Joel Munene Muchira, David Mwanza Wanjeh, Emilija Janevik-Ivanovska PP62 University Master Program of Radiopharmacy – step forward for Good Radiopharmacy Education Emilija Janevik-Ivanovska, Zoran Zdravev, Uday Bhonsle, Osso Júnior João Alberto, Adriano Duatti, Bistra Angelovska, Zdenka Stojanovska, Zorica Arsova Sarafinovska, Darko Bosnakovski, Darinka Gorgieva-Ackova, Katarina Smilkov, Elena Drakalska, Meera Venkatesh, Rubin Gulaboski PP63 Synthesis and preclinical validations of a novel 18F-labelled RGD peptide prepared by ligation of a 2-cyanobenzothiazole with 1,2-aminothiol to image angiogenesis. Didier J. Colin, James A. H. Inkster, Stéphane Germain, Yann Seimbille

imaging at late time points, but also provides the possibility to achieve the same image contrast using less radioactivity as well as detect low-level integrin expression. Discussion/conclusion: [ 68 Ga]FSC(succ-RGD) 3 shows the advantages in the respect of delayed imaging, reduced radiation dose as well as monitoring low-level integrin expression in tissues in comparison to [ 68 Ga]NODAGA-RGD, therefore it is a promising agent for integrin α v β 3 receptor imaging.

OP05
A new NPY-Y1R targeting peptide for breast cancer PET imaging Ait-Mohand Samia 1 , Dumulon-Perreault Véronique 2 , Guérin Brigitte 1,2 binding affinity. The aim of this study was to show the benefit of multimeristation on the targeting behaviour using a CCK2receptor targeting, metabolically unstable Minigastrin peptide (MG11). Materials and methods: Fusarinine C, a cyclic siderophore bearing three amino residues, was chosen as chelating agent and up to three peptide sequences (MG11= D-Glu1, desGlu2-6]-minigastrin) were conjugated by using maleimide chemistry. Radiotracers were labelled with 68Ga as well as with 89Zr following standard radiolabeling protocols. For in vitro characterisation stability studies, determination of the partition coefficient and cell uptake studies were performed. In vivo experiments included biodistribution studies (1h p.i) and static micro PET/CT imaging and were carried out in tumour xenograft bearing balb/c nude mice. Results: Peptide conjugates could be labelled with 68Ga (5-15min RT, pH4-5) and 89Zr (60min, RT, pH7) achieving radiochemical yields of more than 98%. All complexes showed excellent stabilities in the presence of EDTA, DTPA, FeCl3 and in human serum after certain timepoints. Partition coefficient (logP) values ranging from -1 to -3 revealed a hydrophilic character of the radiotracers. As expected a decrease of hydrophilicity correlated with increasing grade of multimerisation. The cell uptake ranged from 10 to 15% per mg protein and could be reduced significantly by blocking with human minigastrin indicating specific receptor binding of all conjugates. Biodistribution studies showed a tumour uptake ranging from 5% (monomer) to approximately 10% ID/g (multimer) one hour post injection. Tumour to organ ratio was decreased by multimerisation and especially the kidney retention was increased significantly by the di-and trimeric radiotracers. Static animal imaging one and two hours after injection of 68Ga labeled conjugates confirmed the outcome of the biodistribution studies. 89Zr labeled counterparts showed very similar results but after 24 hours post injection the trimeric bioconjugate showed much better tumour imaging ability than the corresponding mono-and dimer. Discussion/conclusion: Though these results are preliminary multimerisation seems to correlate with higher tumour uptake leading to better late timepoint imaging but high kidney retention seems to be a major limitation. Stability studies are ongoing.
Introduction: The Al18F-labelling strategy involves formation of aluminium mono[18F]fluoride ({Al18F}2+) which is trapped by a suitable chelator -mostly bound to a biomolecule-in aqueous medium.1At this moment however, the need for elevated temperatures (100-120°C) limits its widespread use. Therefore, we designed new restrained complexing agents (RESCAs) for use of this strategy at moderate temperature. RESCA1 is an acyclic pentadentate ligand with a N2O3 coordinative set that is able to complex {Al18F}2+ efficiently at 25°C. To evaluate the stability and kinetic inertness of the chelate in vivo, RESCA1 was conjugated to human serum albumin (HSA) and labelled with {Al18F}. The Al18F-labelled conjugate was monitored in vivo for 6 h p.i. Materials and methods: HSA was reacted with RESCA1-TFP. RESCA1-HSA (7.5 mg, 110 nmol) in 750 μl sodium acetate buffer (0.1 M, pH 4.5) was added to a freshly prepared {Al 18 F} 2+ solution (1.4 GBq, 50 nmol AlCl 3 , 12 min, RT). The product was purified using a PD-10 column and RCP was determined with SEC-HPLC. To test stability in serum, Al 18 F-RESCA1-HSA in 100 μl PBS was added to rat serum (900 μl), kept at 37°C and monitored up to 4 h. Ex vivo biodistribution was studied at 1 h, 3 h and 6 h p.i. of Al 18 F-RESCA1-HSA (2-7.5 MBq) in healthy female rats. Small-animal whole-body PET imaging was performed using a FOCUS 220 tomograph. Results: RESCA1-HSA was obtained with a chelator-to-protein ratio of 3, estimated by ESI-TOF-HRMS analysis. Al18F-RESCA-HSA was prepared in high RCY (>70%) and purity (>95%) in < 30 min. 91% of product was still intact in rat serum after 4 h incubation. Distribution in rats showed high retention in blood with 5.42 ± 0.23% ID/g, 4.93 ± 0.22% ID/g and 3.66 ± 0.06% ID/g at 1h, 3h and 6 h respectively from which the blood biological half-life was calculated to be 8.6 h. No significant increase in bone uptake was observed, indicating excellent in vivo stability of the Al18Flabelled construct. Discussion/conclusion: We successfully labelled for the first time a heat-sensitive biomolecule via the Al18F-method in one radiolabelling step. Al18F-RESCA1-HSA showed excellent stability and favourable properties for PET blood pool imaging applications.
Introduction In the last years, the Cu(I)-catalyzed Huisgen [3+2] cycloaddition between terminal alkynes and azides emerged as a powerful tool in F-18 radiolabelling of biomolecules such as peptides, because of its regioselectivity, mild aqueous organic conditions, reduced reaction times, and high yields. (1) .A weak point of the method is the lack of suitable commercially available, stable precursors. (2) In this paper we report the synthesis and F-18 radiolabelling of a new, versatile, easy to handle, and stable azido precursor useful for clickchemistry. Materials and methods: Reagents and solvents were purchased from Sigma-Aldrich. [ 18 F]Fluoride was produced with an IBA Cyclone 18/9 cyclotron. Radioactive synthesis were carried out on a fully automated radiosynthesis module (GE TracerLab FX-FN Pro), and analyzed by analytical RP-HPLC with UV and radiochemical detectors. Non-radioactive compounds were fully characterized by NMR, ESI-MS and IR. Results: A series of bifunctional precursors, bearing the azido moiety and different leaving groups (e.g. tosylate, mesylate, iodo), coupled to a short polyetyleneglycol chain (to improve their stability and hydrophilicity) were designed and successfully prepared following a ten-step synthetic pathway. A protection-deprotection strategy of functional groups achieved the precursors and the fluorinated reference with good yield and purity. Precursors were radiolabelled with F-18 and then coupled to propargylglycine as alkyne counterpart.
[ 18 F]Fluoride was purified following standard procedure, and nucleophilic displacement of the iodo leaving group took place at 100°C, in 20 min. The resulting labelled azide was successfully purified using a Sep-Pak tC18 cartridge (51% radiochemical yield not decay corrected, 93% radiochemical purity). The purified azide was then conjugated to propargylglycine, showing 52% conversion within 30 min at room temperature. Purification and formulation have still to be optimized. Discussion/conclusion: A new optimized precursor useful for F-18 radiolabelling and click-chemistry was prepared. It demonstrated to be effective in radiolabelling non-protected alkynyl-modified aminoacids, by a fully automated synthetic procedure. Good results, in terms of radiochemical yield and purity, were obtained from the iododerivative precursor. Purification and formulation of the final cycloaddition product are in progress.

OP12
A general applicable method to quantify unidentified UV impurities in radiopharmaceuticals R.P. Klok 1  Introduction: Radiopharmaceuticals are released for administration by a quality control procedure against pre-set specifications. One of these release specifications is the chemical purity of the drug product, determined with High Pressure Liquid Chromatography (HPLC) and UV detection. In the European Pharmacopeia (EP) hardly any specifications are given for the chemical purity of a radiopharmaceutical. When unknown impurities are present in the chromatogram, the decision if the radiopharmaceutical can be released, is very frequently based on unclear parameters like 'no unidentified UV signals present'. There is a need for an objective specification in order to have a save and reliable release. Aim: The purpose of the presented work is to define a generally applicable method to define tolerances for unidentified impurities in radiopharmaceuticals. FES. Quantification of the carrier signal in the UV chromatogram was determined by use of calibration curves, utilizing Chromeleon® 6.8. Unidentified impurities were semiquantified utilizing the surface area in the UV chromatogram relative to the quantified carrier signal. Based on the EP. monography of [11C]Flumazenil and [18F]FET, the specification for unidentified UV impurities was determined to be 0.22 pmol/injection volume for a single unidentified impurity and 0.88 pmol/injection volume for the total of unidentified impurities. This specification was tested for over 500 batches of the radiopharmaceuticals and compared to the less specific parameter 'no unidentified UV signals present'. Results: In a pilot assessment we encountered in 5-10% cases unidentified UV impurities leading to rejection of the batch, based on the specification 'no unidentified UV signals present'. Of these rejected batches 25% was also rejected with the new defined specification. Reason for this reduced number of rejections is that with the new specification the presence of unidentified impurities is evaluated objectively. The analysis of the full database is currently on-going. Discussion/conclusion: With this method the amount of unidentified impurities can be estimated in an optimal and objective way, utilizing EP limits of [11C]Flumazenil and [18F]FET, without operator variability. Université de Lorraine, F-54500 Vandoeuvre les Nancy -France; 2 NancycloTEP, Plateforme d'imagerie expérimentale, 54500 Vandoeuvre les Nancy -France; 3 CNRS, UMR 7565 SRSMC, F-54506 Vandoeuvre les Nancy -France; 4 CHU de Nancy-Brabois, F-54511 Vandoeuvre les Nancy -France Correspondence: Collet C. -Université de Lorraine, F-54500 Vandoeuvre les Nancy -France EJNMMI Radiopharmacy and Chemistry 2016, 1(Suppl 1):OP13 Introduction: The 18 F-labeling of peptides for PET applications has been used for many years. 1 However, the sensitivity of these peptides does not allow their direct radiolabelling under harsh conditions, except few recent examples. A solution is to use a prosthetic group, an easily radiolabeled small molecule, subsequently coupled in mild condition to the peptide. In continuation of our previous work, 2 we therefore propose to develop and use new C-glycosidebased prosthetic groups. The use of sugar derivatives as prosthetic group would improve bioavailability and pharmacokinetic properties of peptides. Materials and methods: These C-glycoside derivatives should have a good leaving group thus allowing easy substitution by fluorine-18, i.e. triflate. A copper catalyzed azide alkyne cycloaddition (CuAAC) was then used for coupling these carbohydrates with a peptide. Some model peptides containing a cysteine residue as RGDC and c(RGDfC) are used. The high nucleophilicity of the thiol function can thus be exploited to prepare S-propargylated derivatives. The fully automated radiosynthesis of these [ 18 F]fluoro-glycopeptides was performed on an AllInOne® (Trasis) synthesizer. Results: Triflated precursors of these C-glucosides prosthetic groups and the non-radioactive references were synthesized in alpha and beta configuration. Fluoride-18 radiolabeling was optimized and the automated radiosynthesis of [ 18 F]fluoro-glycopeptides with some model peptides (RGDC, c(RGDfC)) was presented.

Materials and methods:
Introduction: In nuclear medicine a remarkably high demand of 68 Ga-radiotracers has emerged during the last decade. For a variety of non-68 Ga-containing radiotracers a microfluidic approach for their syntheses could be established, enabling an enhancement of yields due to high surface-to-volume ratios 1,2 . In this proof-of-principle study, the 68 Ga-radiolabeling of PSMA HBED-CC and NODAGA-RGD using a microfluidic approach was evaluated. Furthermore, adding TWEEN 20 (a surfactant suitable for in vivo applications) and its impact on the radiochemical yield was explored. Materials and methods: The syntheses of 68 Ga-PSMA HBED-CC and 68 Ga-NODAGA-RGD (both precursors from ABX) were performed using an Advion NanoTek LF microfluidic device. The system incorporates a flow-through reactor that consists of a silica capillary (l=2 m, Ø100 μm, V=15.6 μL). 68 Ga 3+ was obtained from a 68 Ge/ 68 Ga-generator (3.7 GBq; Obninsk) according to a fractionized protocol. The precursor and 68 Ga 3+ were loaded in two storage loops and distinct volumes thereof were pushed through the reactor with different flowrates (30, 50, 80 μL/min) at different temperatures (25, 50, 80, 100, 120, 150°C) using NaOAc and HEPES for pH adjustment, respectively. Additionally, the influence of TWEEN 20 as a surfactant, to reduce known adsorption effects in microfluidic tubing, was investigated. Results: Accomplished experiments revealed feasibility of 68 Ga-labeling of PSMA HBED-CC and NODAGA-RGD using a microfluidic device. All temperatures and flowrates resulted in mean radiochemical yields in a range of 20-55%. Syntheses at higher temperatures and flowrates proved to be more efficient. For instance, HEPES buffered syntheses at 100°C and flowrate of 80 μL/min yielded 68 Ga-PSMA HBED-CC in 42.6 ± 22.1 % (n=10) and 68 Ga-NODAGA-RGD in 49.7 ± 32.5 % (n=7). Applying the same parameters, TWEEN 20 could strikingly improve the yield of 68 Ga-PSMA HBED-CC to 70.8 ± 16.8 % (n=13). Discussion/conclusion: This study provides the proof-of-principle of 68 Ga-labeling in a microfluidic "flow-through" system. The application of TWEEN 20 led to drastically increased yields of 68 Ga-PSMA HBED-CC due to its surfactant nature. As a result, this microfluidic approach will be pursued to increase availability of 68 Ga-radiopharmaceuticals according to the dose-on-demand principle.

OP16
Surprising reactivity of astatine in the nucleophilic substitution of aryliodonium salts: application to the radiolabeling of antibodies François Guérard 1 , Yong-Sok Lee 2 , Sébastien Gouard 1  Introduction: Aryliodonium salts have recently emerged as versatile precursors for the synthesis of 18 F-radiolabeled compounds for PET imaging. 1,2 However, little is known about the applicability of these reagents for labeling with the heaviest radiohalogens iodine and astatine, both useful for nuclear imaging and/or therapy. 3 In this study, we aimed at probing the reactivity of radioiodide ( 125 I) and astatide ( 211 At) towards diaryliodonium salts in order to assess their usefulness for radiolabeling biomolecules of interest in nuclear medicine. Materials and methods: First, parameters of radio-iodination and astatination reaction (solvent, temperature, duration and counter-ion of iodonium) were studied on model compounds. Bifunctional iodonium salts were then designed, allowing the synthesis of [ 125 I]-SIB and [ 211 At]-SAB, two prosthetic groups widely used for radioiodination and astatination of biomolecules. Both [ 125 I]-SIB and [ 211 At]-SAB were conjugated to the multiple myeloma targeting mAb 9E7.4 (anti-CD138). Conjugation yields and resulting immunoreactivity were compared with the conventional arylstannane chemistry approach. Results: Initial reaction parameters studies highlighted a striking difference of reactivity between radio-iodide and astatide that could not be anticipated from the trends observed within the halogen series. Not only the astatination reaction was highly efficient at much lower temperature than iodination, but it appeared also solvent and counter-ion independent (not iodination). Thermochemical studies highlighted a large difference of activation energy in acetonitrile between both halogens with Ea = 23.5 kcal/mol and 17.2 kcal/mol for radio-iodination and astatination, respectively. Quantum chemical calculations support the hypothesis that astatination occurs via a monomeric iodonium complex whereas iodide occurs via a dimeric complex which requires more energy for the reaction to proceed. This explains the large reactivity difference observed. Radiolabeling of an antibody with specifically designed iodonium salts outperformed conventional arylstannane chemistry approaches in terms of global efficiency (radiochemical yields >90%, conjugation yields ≈ 75%, and simpler purification: no HPLC needed) with excellent preservation of immunoreactivity of the IgG with both radionuclides and less concerns regarding the toxicity of precursors and side products. Discussion/conclusion: In comparison with the conventional arylstannane approach, aryliodonium salts appear as more efficient precursors for preparation of radio-iodinated and astatinated Introduction: SPECT/CT imaging with 111 In-BzDTPA-pertuzumab detected trastuzumab (Herceptin)-mediated HER2 downregulation in human breast cancer xenografts in mice and was correlated with a good response to treatment. This agent is now being studied in a Phase I/II clinical trial sponsored by OICR (PETRA; ClinicalTrials.gov identifier: NCT01805908). Our objective was to develop and characterize a second-generation positron-emitting analogue for PET/CT imaging, 64 Cu-NOTA-pertuzumab F(ab') 2 , to provide greater sensitivity, more accurate radiotracer quantitation and a lower radiation absorbed dose. Materials and methods: To determine the optimal dose, mice with subcutaneous HER2-overexpressing tumours were injected with 5, 50, 100 or 200 μg of 64 Cu-NOTA-F(ab') 2 (2.2±0.6 MBq) and sacrificed at 24 h p.i. for biodistribution. To determine the normal tissue distribution, pharmacokinetics and radiation dosimetry of 64 Cu-NOTA-F(ab') 2 , non-tumour bearing Balb/c mice were administered 50 μg of 64 Cu-NOTA-F(ab') 2 (2.9±0.3 MBq) and sacrificed at select time points. Three groups of mice bearing HER2overexpressing tumours were injected with 64 Cu-NOTA-F(ab') 2 (50 μg; 10.6±0.4 MBq) with or without administration of pertuzumab (1 mg) 24 h before, or with 64 Cu-NOTA-F(ab') 2 prepared from nonspecific human IgG (50 μg; 8.2±1.9 MBq) to demonstrate specificity. Mice were imaged with PET/CT at 24 and 48 h p.i. and sacrificed for biodistribution. Results: The 50 μg dose of 64 Cu-NOTA-F(ab') 2 showed the highest tumour to blood ratio, followed by the 100, 5, and 200 μg doses (18.2±7.2, 15.4±0.8, 14.0±5.0, and 10.9±1.8, respectively). In nontumour bearing mice, only the kidney retained significant radiotracer uptake at 24 h p.i. (49.1±5.9 %ID/g). Initial estimates for t ½ α and t ½ β were 1.2 h and 6.0 h, respectively. The projected total body radiation absorbed dose to humans was 0.02 mSv/ MBq, half that estimated for 111 In-BzDTPA-pertuzumab. Tumour to normal tissue contrast of PET/CT images appeared similar between the 24 and 48 h p.i. imaging time points. Tumour accumulation of 64 Cu-NOTA-F(ab') 2 was significantly higher in mice administered 64 Cu-NOTA-F(ab') 2 without pertuzumab blocking (8.4 ±3.4 %ID/g) relative to mice pre-injected with 1 mg of pertuzumab (3.9±0.5 %ID/g; P < 0.05), and mice administered 64 Cu-NOTA-F(ab') 2 prepared from non-specific human IgG (2.7±0.5 %ID/g; P < 0.05). Discussion/conclusion: 64 Cu-NOTA-F(ab') 2 is HER2 specific and can visualize HER2-overexpressing tumours at 24 or 48 h p.i. with PET/CT imaging. The lower projected radiation absorbed doses for 64 Cu-NOTA-F(ab') 2 compared to 111 In-BzDTPA-pertuzumab may make this a more attractive imaging agent to detect trastuzumabmediated HER2 downregulation in breast cancer. Supported by grants from the OICR Smarter Imaging and High Impact Clinical Trials (HICT) Programs.

OP18
Development of radiohalogenated analogues of a avb6-specific peptide for high LET particle emitter targeted radionuclide therapy of cancer Salomé Paillas 1 , John Marshall 2 , Jean-Pierre Pouget 3 , Jane Sosabowski 1 Introduction: Targeted radionuclide therapy (TRT) of solid tumors has a limited efficacy mainly because these tumours have high radioresistance and take up limited amounts of radiolabeled vectors. Strategies to overcome this include the use of small peptides combined with radionuclides that emit highly cytotoxic particles, namely high linear energy transfer (LET) particles such as alpha particles and Auger electrons. We have chosen to target the epithelial-specific integrin αvβ6, which is weak or absent on normal tissues but is upregulated on many cancers where it is strongly associated with reduced survival. One targeting vector is a 20 mer peptide, A20FMDV2 which we have previously used to image αvβ6-positive tumours with SPECT (In-111) or PET (F-18, Ga-68). The peptide showed extremely high kidney retention when radiolabelled with radiometals, but this was not seen with the F-18 analogue. Due to anticipated dose-limiting toxicity in kidney for radiometal-based TRT, we have developed a peptide suitable for radiohalogenation with the Auger electron emitter I-125 and the alpha particle emitter At-211. Materials and methods: The 20 mer high affinity αvβ6-targeting peptide, A20FMDV2 used in previous work has been derivatised to contain a trimethylstannyl benzamide moiety so that it can be radiolabelled with I-125 and At-211. The peptide has been radiolabelled with I-125 and radioligand binding and internalization assays have been carried out in cells that overexpress αvβ6 and compared with that of the 111In-DTPA-A20FMDV2 studied previously. Clonogenic assays have been carried out on both the nonradiolabelled peptide and the radiolabelled analogue in both αvβ6-positive and negative cells to determine the effect of high LET irradiation. Results: Radiolabelling efficiency with I-125 was >91 % and the analogue showed high binding affinity and rapid internalisation. Clonogenic assays showed that the non-labelled peptide alone was able to inhibit cell growth and that this effect was not seen on αvβ6negative cells. This effect was enhanced when radiolabelled with a high LET particle emitter. Discussion/conclusion: The αvβ6-specific peptide when radiolabelled with a high-LET particle emitter shows promise as an agent for targeted radionuclide therapy.

OP19
Ligand Specific Efficiency (LSE) as a guide in tracer optimization Emmanuelle Briard 1 , Yves P. Auberson 1 , John Reilly 2 , Mark Healy 2 , David Sykes 3 1 only if the nonspecific binding remains constant. This work aimed at identifying an index taking into account the relationship between these two parameters, to guide optimization from the early stage of tracer development projects. Materials and methods: Similarly to the Ligand Efficiency (LE) index, we explored the usefulness of the Ligand Specific Efficiency index (LSE), which we defined as the ratio between affinity (expressed as e.g. pIC 50 or pK d ), and the logarithmic value of the experimental non-specific binding measurement, CHI(IAM). [Jiang] LSE provides a measure of affinity, normalized to non-specific binding. It shows how efficient the ligand is at binding to the desired target, compared to all other non-specific binding partners.
Results: A series of well-described PET tracers was evaluated to set the LSE threshold. This analysis showed that an LSE > 5 and preferably LSE > 5.4 is required for a successful tracer. This concept was applied to the development of a prostacyclin receptor (IPR) tracer. Our chemical starting point was Ro1138452, [Clark] which we selected based on encouraging overall properties, including a high affinity for IPR (Ki = 0.23 nM). In contrast, its CHI(IAM) value of 58 clearly indicated a high tendency for non-specific binding. Despite such high non-specific binding, Ro1138452 has a LSE value of 5.1, which is close to the minimum value that would be expected for a successful PET tracer. This raised hope that some improvement in binding specificity would allow the use of a close derivative for imaging purposes. The use of LSE during the IPR tracer optimization will be presented. Discussion/conclusion: LSE is based on a rather intuitive concept, in the sense that a good PET tracer candidate should have the optimum balance of affinity and binding specificity. It is a convenient index to evaluate and compare molecules based on measured, rather than in silico values, and is applicable independently of target and chemotype. It is a useful index from the beginning of a project, facilitates the selection of the most promising scaffold and guides their optimization.

OP23
The radiosynthesis of an 18F-labeled triglyceride, developed to visualize and quantify brown adipose tissue activity Andreas Paulus 1 , Wouter van Marken Lichtenbelt 1 ,Felix Mottaghy 2,3 , Matthias Bauwens 1,3 Introduction: Brown adipose tissue (BAT) is an interesting type of tissue that receives major interest as a target to combat obesity. It was (re-)discovered in 2009, when PET-CT studies with [ 18 F]-FDG showed its presence and metabolic activity even in adult humans [1]. It is however difficult to quantitatively assess this metabolic activity using [ 18 F]-FDG, as BAT mainly uses lipids as an energy source. Radiolabeled fatty acids, such as [ 18 F]-FTHA, can provide useful information, but are not optimal considering the lipid uptake mechanism BAT is not based on singular fatty acids, but instead triglycerides (in lipoproteins). As such, we aim to develop a radiolabeled triglyceride, hoping this will shed more light on the lipid burning of BAT, thus allowing to calculate the impact of BAT on the total metabolism of the human body. Methods: A fatty acid (C 16 ) BODIPY-Fl dye is radiolabeled with F-18 using an F-18/F-19 exchange reaction of the boron-fluoride core of the BODIPY dye to yield a bimodal PET/fluorescent imaging tool. BODIPY-C 16 is esterified with 1,3 -Diolein and assistance of thionylchloride yielding the resulting fluorescent triglyceride (TG). In vitro experiments with BODIPY-C 16 are conducted to investigate the applicability the dual-modality imaging probe.
Results: BODIPY-C 16 could be radio-labeled in a Lewis Acid assisted F-18/F-19 exchange reaction in a reasonable yield (66%, not corrected for decay) and a final purity after C18 Sep-Pak purification of more than 97%. Esterification of BODIPY-C 16 resulted in a BODIPY-TG with a yield of more than 90% within 30 minutes. First in vitro experiments showed specific uptake of BODIPY-C 16 in BAT and WAT as the compound was located within the lipid droplets of the cell. Direct radiolabeling of the BODIPY-TGL was also successful (60% yield, >97% purity). Discussion/conclusion: First experiments implied radiolabeled BODIPY-C 16 is a promising BAT PET tracer with the opportunity to resolve its metabolic character on a sub-cellular level due to its dual-modality. In vivo imaging of radiolabeled BODIPY-C 16 and BODIPY-TGL, incorporation into micelles as well as further in vitro experiments will be conducted in the near future to investigate the applicability of this tracer in lipid metabolism imaging of BAT.

OP24
Influence of the fluorescent dye on the tumor targeting properties of dual-labeled HBED-CC based PSMA inhibitors Baranski, Ann-Christin 1 , Schäfer, Martin 1 , Bauder-Wüst, Ulrike 1 , Haberkorn, Uwe 2 , Eder, Matthias 1 , Kopka, Klaus 1 Introduction: Image-guided cancer surgery using fluorescence imaging has high clinical impact and already shows potential to improve the outcome of oncological surgery (1). As first clinical experiences with the 68 Ga-labeled PSMA-targeting inhibitor Glu-urea-Lys-Ahx-HBED-CC (PSMA-11) demonstrated high and specific tracer uptake in prostate cancer lesions a fluorescence dye conjugate of PSMA-11 might represent a promising bimodal tracer. The combination of preoperative staging by means of PET/CT and PET/MRI, followed by image-guided surgery will further improve the accuracy of detecting PSMA-positive tumor lesions by merging the strengths of both techniques. Therefore, various fluorescent dyes were conjugated to the inhibitor PSMA-11 to determine the impact of the dye conjugation on the ligand's in vitro and in vivo characteristics. Materials and methods: The optical-dye labeled tracer PSMA-HBED-CC-FITC, PSMA-HBED-CC-AlexaFluor488 and PSMA-HBED-CC-IRDye800CW were synthesized based on PSMA-11. The binding properties were analyzed in a competitive cell binding assay followed by internalization experiments in human PSMA expressing LNCaP cells. Biodistribution studies were performed in LNCaP tumor-bearing mice (BALB/c nu/nu) to determine specific tumor uptake and pharmacokinetic properties. Results: Comparative cell binding experiments revealed a high affinity to PSMA expressing cell lines for all conjugates, which is in line with the values obtained with the reference 68 Ga-PSMA-11. The radiolabeled fluorescent-dye conjugates showed specific cell uptake and were effectively internalized into the PSMA expressing cell line LNCaP. First in vivo results indicated slightly varying pharmacokinetic properties depending on the fluorescent dye. The FITC-and AlexaFluor488-conjugates revealed a higher tumor uptake compared to 68 Ga-PSMA-11, while a minor, but still satisfying uptake was detected for the IRDye800CW-conjugate. Discussion/conclusion: Conjugation of a fluorescent dye to the wellestablished imaging agent PSMA-11 showed rather minor dyedependent impact on cell binding properties, tumor uptake and the pharmacokinetic characteristics. In order to further improve the biodistribution profile of the IRDye800CW-conjugate, structural optimization will be done. These first preclinical results emphasize the potential of a dual-labeled PSMA inhibitor to serve as a multimodal imaging agent, enabling sensitive pre-, intra-and post-therapeutic identification of metastases with one and the same molecule.

OP25
[18F]MEL050 as a melanin PET tracer : fully automated radiosynthesis and evaluation for the detection of pigmented melanoma in mice pulmonary metastases Chaussard M 1,2 , Hosten B 1,2,4 , Vignal N 1,2,4 , Tsoupko-Sitnikov V 1,2 , Hernio N 1,5 , Hontonnou F 1,5 , Merlet P 1,2,5 , Poyet JL 3,5 , Sarda-Mantel L 1,2,5 , Rizzo-Padoin N 1 Introduction: Melanoma is a highly malignant cutaneous tumor of melanin-producing cells. Early detection of melanoma is the best way to reduce mortality. Several radiolabeled imaging probes have been evaluated for melanoma imaging. MEL050 is a synthetic benzamide-derived molecule that specifically binds to melanin with high affinity. Our aim was to implement a fully automated radiosynthesis of [ 18 F]MEL050, including HPLC purification and formulation, using for the first time, the AllInOne radiosynthesis platform (Trasis, Ans, Belgium), and to validate this PET radiotracer in vivo in a mouse model of melanoma. Materials and methods: [ 18 F]MEL050 was synthesized using a one-step bromine-for-fluorine nucleophilic heteroaromatic substitution. Briefly, [ 18 F]MEL050 was prepared from a bromoprecursor, using no-carrier-added 18F-KF-Kryptofix 222 (dimethylformamide, 150°C, 6 min), followed by preparative HPLC purification (C18 column (300x7.8 mm, 7 μm), isocratic elution with acetonitrile/20 mM ammonium bicarbonate (20:80, v/v), 3.0 ml/min) and cartridge-reformulation (Sep-Pak® Plus C18 environmental) of the collected fraction. Radiochemical and chemical purity, stability and specific activity measurements were monitored using analytical HPLC. Chemical identity of the labeled compound [ 18 F]MEL050 was assessed by co-injection with non-radioactive standard MEL050. Experimental model of pulmonary metastatic melanoma was obtained by IV injection of B16-F10 cells in NMRI mice. Mice (n=8) were imaged 15 days after inoculation, using INVEON microPET/CT device (Siemens), after IV injection of 0.36 ±0.04MBq/g of [ 18 F]MEL050. Dynamic and static acquisitions were acquired from time of injection to 2h after tracer injection. The maximum percentage of [ 18 F]MEL050 Injected Dose per g of lung tissue (%ID/g Max) was determined using ROIs manually drawn on 1h-post injection PET images, and correlated to ex-vivo findings. Results: The fully automated radiosynthesis of [ 18 F]MEL050 required an overall radiosynthesis time of 60 min, with an endof-synthesis yield of 20-26% (n=12). Isocratic semi-preparative HPLC allowed efficient separation of [ 18 F]MEL050 from the reaction mixture. The radiotracer was consistently produced with radiochemical purity higher than 99%. The specific activity was in the range of 177-325GBq/μmol and the product stability was maintained at RCP>98% over 6 h. PET Introduction: Urea-based inhibitors of the prostate-specific membrane antigen (PSMA) are well known and promising candidates for the diagnosis (1, 2) and therapy of prostate cancer. The aim of the project was the development of F-18 labeled PSMA ligands based on the theranostic compound PSMA-617. The compounds evaluated during the preliminary experiments showed a high uptake in non-target organs caused by their relatively high lipophilicity. Therefore we currently reduce this lipophilicity by the addition of charged amino acids to the linker region of our PSMA inhibitors (3). Materials and methods: The PSMA binding motif Glu-NH-CO-NH-Lys was synthesized by a well-established method (4) using solid phase chemistry and subsequently an amino acid linker was built up by fmoc-based solid phase peptide synthesis (SPPS). The nonradioactive reference compounds were also prepared analogically and eventually conjugated by 6-fluoronicotinic acid. After separation from the resin and deprotection the peptidomimetics were labeled using the TFP-ester of 6-[ 18 F]fluoronicotinic acid as prosthetic group. The K i values of all compounds were determined by competitive binding assays on PSMA-positive LNCaP cells against 68 Ga-PSMA-10 (5) using the respective cold reference compounds. Additionally, the cellular internalization of the radiofluorinated ligands was determined. Results: All 18 F-labeled PSMA-inhibitors presented in this study showed low nanomolar affinities towards PSMA, usually paired with high internalization ratios of more than 15 %, shown in vitro. Among those PSMA-1007 showed an outstandingly high internalization ratio of about 70 % while the K i was in the typical range (6 nM). Hence PSMA-1007 was further evaluated in vivo. The organ distribution showed a high and specific tumor uptake of 8.0±2.4 %ID/g. Finally, the PSMA-targeting potential of PSMA-1007 was further demonstrated by dynamic μPET experiments. Discussion/conclusion: Based on our experience with PSMA-617 and preliminary results we developed a series of radiofluorinated PSMA inhibitors with high affinities and internalization ratios. Among those a promising candidate for further translation into the clinic has already been found. This candidatenamely PSMA-1007is currently transferred into first-in-man studies. Nevertheless further optimization of the lead compound is still ongoing.

OP27
A novel radiolabeled peptide for PET imaging of prostate cancer: 64Cu-DOTHA2-PEG-RM26 Mansour Nematallah 1 , Paquette Michel 1 , Ait-Mohand Samia 1 , Dumulon-Perreault Véronique 2 , Lecomte Roger 1,2 , Guérin Brigitte 1,2 Introduction: The Gastrin-Releasing Peptide Receptor (GRPR) is overexpressed in a wide variety of prostate cancers, hence its interest as a potential biomarker. As such, previous work used different radiolabeled GRPR-binding peptides to specifically target tumors in vivo (1, 2). Recently, we synthesized a novel bifunctional chelator bearing hydroxamic acid arms, called DOTHA 2 , for which our group demonstrated fast and stable complexation to 64 Cu (3). The goal of this study was to develop a GRPR antagonist, D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 (RM26), conjugated to the novel [ 64 Cu]-DOTHA 2 to visualize prostate tumor by PET imaging. Material and methods: DOTHA 2 -PEG-RM26 was synthesized on solid support. The inhibition constant (K i ) was measured on PC3 cells. Dynamic PET images were acquired during 60 minutes after bolus administration on nu/nu male mice bearing PC3 tumors. Biodistribution studies were performed at different time points, using balb/c male mice and nu/nu male mice bearing PC3 tumors. To assess specific binding, a cohort received 500 nmol/kg of unlabeled peptide 15 minutes prior tracer injection for both PET and dissection studies. Results: The K i of Cu-DOTHA 2 -PEG-RM26 was in the low nanomolar range (0.68 nM). DOTHA 2 -PEG-RM26 complexed 64 Cu with fast kinetics at room temperature. The radiopeptide showed high stability, low residual activity in various tissues and fast clearance in normal mice. Small animal blocking experiments showed a significant uptake drop compared to tracer by biodistribution in the GRPR-rich pancreas for both balb/c and nu/nu mice (respectively p< 0.05 and p < 0.01 at 30 min). A significant uptake decrease from 5.3±0.8%ID/g to 3.4 ±1.4%ID/g was also observed in PC3 tumors when unlabeled peptide was added in biodistribution experiments at 30 minutes, whereas a significantly reduced tumor uptake was also assessed by PET imaging from 20 to 60 minutes (p<0.05) post-injection. Discussion/conclusion: The use of [ 64 Cu]-DOTHA 2 -PEG-RM26 is promising for visualizing prostate tumors. These preliminary data suggest that DOTHA 2 can be used to develop many other peptide-and protein-derived PET tracers. Material and methods: [ 18 F]Amylovis® was synthesized by nucleophilic substitution of the tosyl group of the precursor. Thirty five healthy male Balb/C mice of 10-12 weeks were divided into 6 groups of 5 animals each and injected with similar doses of [ 18 F]Amylovis® through a lateral tail vein. Blood samples were collected and the animals were sacrificed at 5, 15, 30, 45, 70 and 180 minutes. Organs of interest were removed and washed with saline. Radioactivity of blood, plasma, urine, faeces, brain, cerebellum, heart, liver, stomach, spleen, bowel, colon, left kidney, muscle, bone and tail was measured in a well counter. To assess protein binding, plasma samples were diluted with acetonitrile and centrifuged at 4000 g. Pellets of proteins and supernatants were separated and their radioactivity measured in a well counter. RadioTLC analysis of plasma were performed for the same purpose in silicagel 60 and mobile phase of acetonitrile/water (95/5). 20μL of each supernatant was analysed by HPLC-RP using a C18 column and acetonitrile/water (75/25) as mobile phase to identify plasma metabolites. Pharmacokinetic parameters (AUC, t 1/2 , C max , Cl, V ss ) were calculated using non-compartmental analysis (NCA). Dynamic PET/CT images of healthy and transgenic APPSwe/ PS1dE9 mice were acquired for 2.5 h after i.v. administration. Immunohistochemistry of control and transgenic mice brains were performed to identify β-amyloid plaques. Results: [ 18 F]Amylovis® crossed blood brain barrier. PET/CT images showed significant differences between healthy and transgenic mice, expressed in Cortex to cerebellum SUV ratio, with maximum difference at 30 minutes. Postmortem studies of immunohistochemistry showed also differences in healthy vs transgenic mice (amyloid positive). Plasma T 1/2 of 37 min. No significant protein binding was observed. Renal and hepatic pathways were the main excretion routes. Some amount of in vivo degradation metabolites appeared in blood from 1 h post-administration. Conclusion: [ 18 F]Amylovis® could be a promising PET radiotracer for amyloid plaques visualization. Introduction: Colony stimulating factor-1R (CSF-1R) is also called as Feline McDonough Sarcoma (FMS), is a type-III kinase receptor. FMS widely expressed and considered to regulate development, maintenance and functioning of mononuclear phagocyte lineage such as monocytes, macrophages, dendritic cells, langerhans cells, microglia and osteoclasts 1 . Over expression of FMS have been implicated in number of disease states including cancer, rheumatoid arthritis, Crohn's disease and Bone disorders. FMS also known to play a key role in microglia differentiation and activation and assuming that it was key mediator in neuroinflammatory process. Materials and methods: All the chemicals and reagents used in the experiments were obtained from commercial sources and used without any further purification. Synthesis of 5-cyano-N-(4-(4-methylpiperazine-1-yl)-2-(4-methylpiperidin-1-yl)phenyl)furan-2-carboxamide and 5-cyano-N-(2-(4-methylpiperidine-1-yl)-4-(piperazine-1-yl)phenyl)fur an-2-carboxamide molecules were done according to literature methods available with slight modifications for radiolabeling experiments 3 . The [ 11 C]-methyl triflate reacts with the precursor in presence of a base at room temperature for 2 minutes gives the carbon-11 radiolabeled [ 11 C]BA-1 which was purified by using semi-preparative reversed-phase high pressure liquid chromatography (RP-HPLC). The peak corresponding the reference compound will be collected and checked for the purity using analytical RP-HPLC. Baseline biodistribution study was performed at 2, 10, 30 and 60 min. respectively. Blocking experiment (10 mg/kg cold compound) was performed at 30 min time point in healthy female adult mice n=3 and compared with vehicle treated batch. In vitro autoradiography experiments were carried on rat brain slices by incubating tracer and cold blocking solution. MicroPET imaging studies were performed on a Focus™ 220 microPET scanner with female rats. Results: Reference and precursor molecules were synthesized with comparable purities and yields reported in the literature, the radiochemical yield (Alkylation yield with [11C]CH3I) 60 % and radiochemical purity of 98 % and specific activity (n=5) 247.3 GBq/μmol. Biodistribution study shows higher tracer uptake into the brain % ID 4 at 2 min time point, main route of excretion via renal and hepatobiliary circulation. High lung uptake was observed with % ID 14 at 2 min. Blocking with cold compound did not observe any blocking effect in brain but we observed blocking in peripheral organs like liver and spleen, also observed slight blocking in pancreas and kidneys. We did not observed any blocking with in vitro autoradiography experiments. Baseline microPET scans suggests good uptake of tracer into brain with SUV 1.2 but with blocking we did not observed any blocking effect despite we observe higher uptake in brain with SUV 2. Discussion/conclusion: We successfully synthesized, [ 11 C]-BA1. In preclinical evaluation we did not observe any significant blocking effect in the brain, we are currently looking for other high affinity molecules for CSF-1R.

OP31
In vivo imaging of the MCHR1 in the ventricular system via Introduction: The melanin concentrating hormone receptor 1 (MCHR1) is predominately expressed in the lateral hypothalamus and is playing a key role in energy homeostasis and obesity. Recently, it has been shown that the MCHR1 is expressed in the ependymal cells of the 3 rd ventricle where it is involved in the regulation of cilia beat frequency [1]. This beating facilitates cerebrospinal fluid circulation, which is crucial for brain function, as defects in ventricular cilia result in hydrocephalus. Our aim was to investigate the potential of the MCHR1 ligand [ 18 F]FE@SNAP [2] for PET-imaging of the MCHR1 in the ventricular system. Materials and methods: In vivo experiments were conducted in naïve male Sprague Dawley rats. For small-animal PET/CT/MR experiments, rats were anesthetized by isoflurane. 25min after [ 18 F]FE@SNAP iv injection (47.8±1MBq; SA: 19.7±6GBq/μmol), vehicle (baseline group, n=3) or 15mg/kg SNAP-7941 (blocking group, n=3) were administered through the tail vein. 75min after tracer injection, the rats were sacrificed. Radioactivity concentrations in brain were calculated and expressed as SUVs. In another set of experiments, [ 18 F]FE@SNAP (51.3±26MBq; SA: 36.1±28GBq/ μmol) as well as vehicle (baseline group, n=3) or 15mg/kg SNAP-7941 (blocking group, n=3) were injected into conscious freely moving rats via a permanent catheter implanted into the jugular vein, thus excluding an influence of anaesthesia. 45min after tracer application, rats were sacrificed, the brain was removed and cut for ex vivo autoradiography. Subsequently, brain slices were put on Phosphor Imager plates for exposure and analyzed with a Cyclone Phosphor Imager the following day. Regions of interest (ROIs) were drawn for the hypothalamic region, the ventricle and a non-target region. ROIs resulted in normalized DLU/ mm 2 ); ratios of ventricle/non-target were calculated. Results: PET/CT/MR experiments: the SUV in the ventricular system was 0.73±0.11 for the baseline group and 0.34±0.07 for the blocking group, which represents a significant reduction. Ex vivo autoradiography showed a distinct uptake in the ventricular, which was significantly reduced in the blocking group. Conclusion: [ 18 F]FE@SNAP evinced specific uptake in the ventricular system of naïve rats regardless their state of consciousness and is therefore a suitable imaging agent for cilia beat function.

OP32
Synthesis of the first carbon-11 labelled P2Y12 receptor antagonist for imaging the anti-inflammatory phenotype of activated microglia B. Janssen 1 , D.J. Vugts 1 , G. Introduction: Activated microglia are a hallmark of neuroinflammation (NI), which in turn is associated with neurodegenerative diseases. The P2Y 12 receptor (P2Y 12 R) is upregulated in the antiinflammatory phenotype of activated microglia, and is not expressed on macrophages and other brain cells. Therefore, P2Y 12 R could be an interesting new target for PET imaging of microglial activation in NI. Recently, a series of P2Y 12 R antagonists with high binding affinity was reported. Based on this series, the purpose of the present study was to label urea derivative 5 (IC 50 = 6 nM) with carbon-11. Materials and methods: The synthesis of sulfonylurea 5, as reference, and azetidine amine 3 and sulfonyl azide 6, as precursors for the radiosynthesis of [ 11 C]5, is depicted below. Carbon-11-labelling was performed via a rhodium(I)-mediated [ 11 C]CO carbonylation reaction [4,5]. [ 11 C]5 was evaluated using in vitro autoradiography of healthy mouse brains and ex vivo biodistribution and radiometabolite analyses in healthy male Wistar rats. Results: Compound 5 and precursors 3 and 6 were successfully synthesised.
Introduction: HDAC6 has been reported as a regulator in numerous diseases ranging from different kinds of cancers (ovarian, breast, prostate,..) to neurological deficiencies (Alzheimer's disease, Huntington's disease, amyotrophic sclerosis,..) [1,2]. Still many characteristics and functions of HDAC6 in these pathologies are unrevealed. Hence, we aim to develop a selective HDAC6 PET tracer to visualize the dynamics of HDAC6 in normal and disease states. Recently, Lu and coworkers synthesized [ 11 C]KB631, a highly potent (IC 50 =1.4 nM) and selective (3700-fold selectivity against HDAC1) PET tracer for HDAC6 imaging in the brain, which showed similar pharmacokinetic properties as tubastatin A [3]. However, [ 11 C]KB631 showed low brain bioavailability [4]. In this regard we opted to use this tracer as a more peripheral imaging agent. The radiosynthesis was redesigned and preliminary results were obtained with a biodistribution study and autoradiography experiments in brain and tumor slices. Materials and methods: [ 11 C]KB631 was synthesized through methylation of the corresponding precursor (300 μg) with [ 11 C]-MeI in anhydrous DMSO (250 μL) at 100°C for 4 min. The biodistribution was studied in NMRI-mice at 2, 10, 30 and 60 min (n = 3/time point) post injection (p.i.). Organs and tissues were harvested and radioactivity was counted in a gamma-counter. Autoradiography studies were carried out with [ 11 C]KB631 on wild-type Wistar rat brain tissue and PC3/LNCaP prostate tumor slices. Slices were incubated with 18.5 MBq/400μL (brain) or 18.5 MBq/250 μL (tumor) of tracer with/without 100 μM of cold authentic reference compound (KB631) or nonstructural related pan-HDAC inhibitor Suberoylanilide hydroxamic acid (SAHA) [5]. Results: Based on prep HPLC integration, the methylation yield was 55 % with a radiochemical purity of 97 % and a specific activity of 48 GBq/μmol. Biodistribution studies indicated low brain uptake (<0.1 %ID at 2, 10, 30 and 60 min) and renal and hepatobiliary excretion. Autoradiography experiments showed regional binding. Binding in brain/tumor slices was highly displaceable in the presence of 100 μM non-labeled reference KB631 (up to 90% for brain, PC3 and LNCaP) or 100 μM SAHA (73% brain, 39% PC3 and 59% LNCaP). Discussion/conclusion: We successfully radiolabeled and evaluated a potential carbon-11 labeled radiotracer for in vitro and ex vivo visualization of HDAC6. However, biodistribution studies indicated low brain uptake, peripheral potency still needs to be further examined. Autoradiography studies showed regional and displaceable binding. Furthermore, radiometabolite studies followed by μPET on a mice tumor model will be performed. (2), potentially enabling P-gp studies in centres without an on-site cyclotron. These analogues showed specific P-gp substrate behaviour, but metabolic stability was poor. The purpose of the present study was to assess whether deuterated analogues would have better metabolic stability.

Materials and methods:
To a dried 18 F/K 2.2.2 /K 2 CO 3 complex, 2bromoethyl-d 4 -tosylate in DMF was added and reacted for 10 min at 90°C to obtain 2-bromo-[ 18 F]fluoroethane-d 4 . This was distilled at 100°C through an AgOTf column at 200°C into a cooled (0°C) vial containing 1.5 mg of (R)-normethyl verapamil (1a) and 3 mg of K 2 CO 3 in ACN. While stirring, this reaction mixture was heated at 120°C for 15 min and purified by HPLC, resulting in 1b. Tracer 2b, 3b and 4b were obtained by direct fluorination of precursors 2a, 3a and 4a and only 2b required final Boc-deprotection with TFA. 1b and 2b were administered to Wistar rats, and the level of labelled metabolites was measured in blood plasma and brain samples. Results: 1b, 2b, 3b and 4b were obtained in a radiochemical yield of 3, 6, 5 and 10%, respectively, a purity >98% and a specific activity >80 GBq·μmol -1 . Results of the metabolite analysis are presented. The deuterated analogues showed improved metabolic stability compared with the non-deuterated compounds. Discussion/conclusion: Labelling of tracers 1b-4b was successful. Although, both 1b and 2b showed significantly increased metabolic stability, total intact tracer levels at 15 min are still lower than desired. The resulting effect of increased metabolic stability for PET imaging will be evaluated in P-gp KO mice. To determine the effect of a deuterated N-methyl group, tracer 3b and 4b were designed and still need to be evaluated for metabolic stability. Introduction: Pulmonary arterial hypertension (PAH) is a disease in which pulmonary arterial obstruction increases vascular resistance, leading to right ventricular failure [1]. Inhibition of transforming growth factor-β (TGF-β) signalling via activin-receptor-like kinase 5 (ALK5) prevents progression and development of pulmonary hypertension [2]. To further understand the role of ALK5 in PAH, the purpose of this study was to synthesize a carbon-11 labeled ALK5 tracer (IC 50 = 5.5 nM) [3] and to assess its potential as a positron emission tomography (PET) ligand for measuring ALK5 expression and activity in vivo. Materials and methods: The [ 11 C]ALK5 tracer was synthesized by a carboxylation reaction. The radiolabeling was carried out by heating [ 11 C]CO 2 , the precursor molecule, isobutyl iodide and BEMP in DMSO for 10 minutes at 75°C. The tracer was evaluated using biodistribution and metabolite studies in Wistar rats (n=4 per time point at 15 and 60 min). In addition, specific binding was assessed using autoradiography on ALK5 expressing MDA-MB-231 tumor sections. Results: The [ 11 C]ALK5 tracer was synthesized with a yield of 18±6 %, a specific activity of 116±31 GBq·μmol -1 and a purity of > 95 %. The tracer showed a normal biodistribution ex vivo and a moderate stability in vivo. The autoradiograms presented binding of the tracer to the tumor sections. Pretreatment of the tumor sections with ALK5 blocking agents (EW-7197, SB-431542 and the ALK5 inhibitor) decreased the binding of the tracer significantly. Conclusion: The ALK5 tracer was synthesized successfully, and initial in vitro and ex vivo studies indicate its potential as a putative tracer of ALK5, warranting further in vivo evaluation. In-EGF-Au were 7.2 and 2.5. Conclusion: An 111 In-labelled EGF-Au-PEG nanosystem was developed. It enabled targeted delivery of a high 111 In payload to an EGFR-positive cancer model that can be potentially exploited for molecularly targeted radiotherapy. Challenges with an excess of glutathione and cysteine and Log P values were also investigated. Furthermore, 1 and 2 were applied to study in vivo stability and the pharmacokinetic profiles on healthy rats. Results: 1 and 2 were obtained in high yield (RCY > 90%). Log P values demonstrate the hydrophilic nature of the radiolabelled peptides: -1.43 for 1; -2.087 for 2. No significant variations in RCPs of both the complexes were observed in challenge experiments with an excess (10 mM) of glutathione and cysteine. A high in vitro stability was observed for both complexes after incubation in human and rat sera as well as in rat liver homogenate; a fast degradation of 2 was detected in kidneys homogenate. 1 retains a high receptor affinity (K d =7.1 ± 0.5 nM). Biodistribution data of 1 display a favorable pharmacokinetic profiles characterized by a fast blood clearance and elimination from normal tissues. A rapid excretion via the renal pathway was observed according to the high hydrophilic character of the radio-conjugate. The effect of the cyclization on the pharmacokinetic profile of 2 was reflected in a reduction of the blood clearance and of the elimination from the other organs, in particular, from excretory organs such as liver and kidneys. Conclusion: Compared with the linear peptide, cyclization negatively affects the biological properties of NAP-NS2 peptide by reducing its binding affinity for MCR1R (Ki: 0.9±0.3 nM for NAP_NS1; 7.1±2.4 nM for NAP_NS2) and decreasing the overall excretion rate of the corresponding [ 99m Tc(N)(PNP3)]-labeled peptide from the body as well as its stability. Thus only the linear [ 99m Tc(N)(PNP3)-labeled peptide is suitable for further investigations in tumor bearing animals. This research was supported by MIUR through PRIN 20097FJHPZ-004 and FIRB "RINAME"2010-RBAP114AMK. Introduction: Preclinical studies demonstrated that [ 68 Ga]NODAGA-RGD allows imaging of integrin α v β 3 expression using PET. Here we present all data (quality control, toxicological study, and dosimetry estimation) necessary to initialize clinical studies, the establishment of the remote controlled synthesis, and data from the phase I clinical study. Methods: Labelling was carried out in a remote controlled synthesis unit under clean room conditions. Quality control included TLC, HPLC, GC, pH control, Ge-breakthrough, half-life, endotoxin content, and control of sterility. Storage stability after 4 h was studied and dose estimations based on animal data were carried out using OLINDA. Sprague-Dawley rats were used for an extended single dose toxicity study. The phase I clinical study included 9 patients with hepatocellular carcinoma (HCC). Static scans at 5, 30, and 60 min p.i. including 5 bed positions each were performed using the Discovery 690 PET/CT. Blood was sampled 30 and 60 min p.i. and urine 60 min p.i. and used for stability studies via HPLC. Results: [ 68 Ga]NODAGA-RGD could be produced in high radiochemical yield and radiochemical purity (HPLC and TLC >99%). The pH in the final isotonic saline formulation was approx. 6. Ethanol content was between 2.5 and 3.0% v/v. No detectable 68 Ge-germanium was found. LAL test revealed 0.7 EU/ml. Sterility tests showed that all samples met the specifications according to Ph. Eur.. No radiolysis of the tracer was found in the formulated solution. The single dose toxicity study showed that the compound was well tolerated in animals. This was confirmed by the clinical study where no severe side effects were observed. High metabolic stability of [ 68 Ga]NODAGA-RGD was found based on the analysis of blood and urine samples. The static scans showed rapid tracer elimination from the body with low background activity in almost all organs. The calculated effective dose was 21.5±5.4 μSv/MBq. Unfortunately, the investigated tumors did not show increased tracer accumulation indicating no or low integrin α v β 3 expression. Conclusion: This study revealed that [ 68 Ga]NODAGA-RGD can be easily produced under GMP conditions and met the requirements for the clinical use. The phase I clinical study with patients bearing HCC did not allow identification of the lesions but demonstrated rapid elimination from the body, high metabolic stability and low radiation burden. The low tracer accumulation in the tumor might be related to low receptor expression, thus further studies are needed to verify the integrin α v β 3 imaging properties. Introduction: In the Netherlands, a modified "light" version of the European GMP, i.e. GMP-z, for the (kit-) production of registered radiopharmaceuticals for individual patients in hospital pharmacies is in effect. However, GMP-z does not allow to synthesize radiopharmaceuticals for clinical trials or therapeutic applications, in which case the European GMP applies. At the MUMC, a growing interest in performing in-house clinical trials with new radiopharmaceuticals and in the synthesis of radiotherapeuticals led to the decision of upgrading the current Radiopharmacy facility. Several restrictions applied: radiopharmaceuticals will not be sold to third parties and the surface area of the entire facility is limited to 55 m 2 (including the production lab, QC lab and separate sluices for personnel and goods). Additionally, the facility had to allow both preparation of routine 99m Tc-compounds as well as GMP-grade radiopharmaceuticals. This study examines the time line of implementation for such a small scale facility and may be relevant to other hospitals considering to comply with this regulation. Materials and methods: A team was founded late 2012, including a radiochemist, QA officer, radiopharmacist, radiation safety officer, clinical physicist and a construction project leader (totaling nearly 5 fulltime-equivalents). User requirements for the facility, hotcells and laboratory equipment were determined. Preliminary building plans were drawn up and several expert companies chosen, specialized in HVAC, cleanroom construction and area and radiation monitoring. Results: For the hotcells, a successful Factory Acceptance Test was performed in February 2015. Construction of the new facility started end of May 2015, starting with the planned installation of the hotcells for which removal of a section from the outer wall was necessary. The second phase of the reconstruction (setting up of a GMP-compliant cleanroom) is scheduled to start January 2016, leading to full operability in April 2016 and, upon inspection by the Dutch Inspectorate (IGZ), GMP-compliant production is expected by the end of 2016. Discussion/conclusion: It is essential to have a high degree of inhouse expertise when starting a radiopharmacy building project. Completely documented construction planning, based on a solid list of requirements, takes 2-3 years to build up and is a necessity to allow timely and high-quality construction.

OP45
Setting up a GMP production of a new radiopharmaceutical Forsback, Sarita 1 , Bergman Jörgen 1 , Kivelä Riikka 2 1 Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland; 2 Turku University Hospital, Hospital Pharmacy, Turku, Finland Correspondence: Forsback, Sarita -Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland EJNMMI Radiopharmacy and Chemistry 2016, 1(Suppl 1):OP45 Introduction: Good Manufacturing Practice (GMP) sets strict requirements for the manufacturing conditions, synthesis and quality of radiopharmaceuticals. Robust production and quality control methods for radiopharmaceuticals are essential for diverse and effective clinical utilization of Positron Emission Tomography (PET). This presentation describes the set up procedure of a new radiopharmaceutical in Turku PET Centre (TPC). All issues other than directly related to GMP such as toxicology, labeling chemistry, analytical methods or documentation for the authorities (i.e. IMPD) are not discussed here. Materials and Methods: Quality standards and product specification are expressed in EU (Annex 15 Qualification and Validation, revision into operation 1 Oct 2015) and European Pharmacopoeia (8 th Edition). The setup of a new radiopharmaceutical at TPC requires existence of the following: Established quality system, Documentation system, Competent personnel, Classified clean rooms, Qualified equipment, System for material management. Initially the specifications for critical materials and primary packing materials of the new radiopharmaceutical must be defined. At TPC specifications for new radiopharmaceutical are: Appearance, Identification, Radioactivity, Radionuclidic identity, Radionuclidic purity, Radiochemical purity, Chemical purity, Residual solvents, Content of ethanol, pH, Sterility, Bacterial endotoxins, Shelf life. Results: After ensuring that the production of a new radiopharmaceutical is robust and repeatable and all analytical methods including sterility and endotoxin tests are validated, the process can be validated according to a written validation plan. In addition bioburden (number of bacteria living on the drug solution before sterilization) must be determined. The aseptic processing of operators must also be confirmed by performing media fills (the performance of an aseptic manufacturing procedure using a sterile microbiological growth medium in place of the drug solution). At TPC the process validation includes three consecutive process validation batches which shall fulfill all specifications for the given radiopharmaceutical. This also qualifies the operator for production. Additional batches must be done in order to qualify more operators. Finally, process validation and documentation is compiled. Process validation report, method description for preparation and quality control and master batch record are written. Discussion/conclusion: After all documentation has been accepted by QA, the new radiopharmaceutical is ready for clinical production and all changes to the process must be performed via change control process. Introduction: The combination of different imaging modalities has received increasing interest over the past decade, as it enables to overcome the limitations of a single imaging modality and ensures enhanced interpretation of diseases and abnormalities in vivo. Dual modality PET/MRI imaging agents, such as radiolabeled magnetic nanoparticles, are promising candidates for a number of diagnostic and therapeutic applications (i.e. MRI-magnetic hyperthermia and radiotherapy). The aim of the present study is to evaluate the efficacy of 68 Ga labeled Fe 3 O 4 superparamagnetic iron oxide nanoparticles (SPIONs) coated with DPD phosphonate, as potential PET/MRI imaging agents. Materials and methods: SPIONs coated with biocompatible DPDphosphonate were radiolabeled with positron-emitting Gallium-68 to quantify the accumulation of the nanoparticles in vivo. In vitro stability studies, in PBS, saline and human serum, were performed to evaluate their aqueous solubility in vivo. In vivo biodistribution study was performed in 9 healthy mice at 30, 60 and 120 min postinjection. Results: 68 Ga-Fe 3 O 4 -DPD SPIONs presented high radiolabeling yield (95%) and proved stable in vitro. The in vivo study exhibited significant liver and spleen uptake at all examined time points in healthy mice, whereas minor fractions attained in other organs. A small fraction of radiolabeled nanoparticles presented in bones is indicative of high affinity of phosphonate to bone tissue. The biodistribution profiles between 68 Ga-Fe 3 O 4 -DPD SPIONs and free 68 Ga-acetate were also compared, indicating different pharmacokinetic behavior for 68 Ga-acetate, with no target tissue and excretion via the kidneys. Conclusion: 68 Ga-Fe 3 O 4 -DPD SPIONs demonstrated high radiolabeling efficiency and in vitro stability and satisfactory in vivo behavior. Cytotoxicity studies to explore the potential toxic effects of the nanoparticles, as well as biodistribution studies in tumor models, are in progress.

OP49
Fast PET imaging of inflammation using 68Ga-citrate with Fe-containing salts of hydroxy acids Introduction: 68 Ga-citrate is one of the radiotracers for PET imaging of inflammation/infection. Gallium (like iron) has high affinity to blood transport proteins (e.g. transferrin) due to their similar physical/chemical properties [1]. One of the functions of transport proteins is delivery iron (gallium too) to inflammation/infection foci for inclusion in metabolic pathways related with eradication of pathology [2]. But excessive gallium bindings with proteins are cause of slow blood clearance, long accumulation time in foci (24-72 h) and exception of application possibility of the short-lived 68 Ga (T½ = 1,13 h) unlike 67 Ga (T½ = 78,26 h). Injection of additional nonradioactive chemical agents (e.g. Fe 3+ containing salts of hydroxy acids: citrate, tartrate, lactate, etc.) competing with gallium to the protein joining (blocking of its metal binding capacity) is one of the ways to solve formulated problem. It can be used for correction of 68 Ga-citrate pharmacokinetics for increasing of the blood clearance, accumulation in foci and fast imaging. Materials and methods. 68 Ga-citrate without/with extra injection of Fe 3+ containing salts (citrate, tartrate, lactate, malate, and ascorbate) was injected mice with modeled lung infection (was got using intra lung injection of cell suspension of E. coli; acute phase of infection was evoluted for 3-4 days). PET/X-RAY Genisys4 (Sofie Bioscience, USA) was used for noninvasive PET imaging with subsequent reconstruction of imaging and their analysis (value of clearance, distribution volume). Scanning time is 10 min.
Results: I. v. injection of Fe 3+ containing salts of hydroxy acids blocked the metal-binding capability of transferrin serum and others and allowed decreasing gallium-68 radioactivity in blood significantly and increasing accumulation in inflammation (3-5 time). It allowed receiving more informative PET-images of inflammation early (for 30-60 min after injection). Pharmacokinetic parameters proved it. Discussion/conclusion. There was no statistically significant difference between 68 Ga-citrate accumulation for different inflammation model because PET imaging is indication of pathological processes and isn't their identification. Introduction: In the installation of methionine as our latest tracer we chose the Eckert and Ziegler Modular-Lab PharmTracer as production module, utilizing the so called «wet-method» for producing methyl iodide. After complete installation in the hot cell, a simplified version of Ph.Eur (Ph Eur monograph 1617) release criterions was used, and the product was found to pass. HPLC showed excellent radio purity and the installation was completed. Materials and methods: Homocysteine thiolactone, iodic acid, 0.1M lithium aluminum hydrid in THF, potassium dihydrogen phosphate were used in the C11-Met synthesis, Methods used are described in Ph.Eur, with the exception of chiral HPLC, in which an Astec Chirobiotic T column with 70:30:0.02, MeOH:-H 2 O:HCOOH eluent was employed. Results: During later analyses for residual solvents in connection with a GC-PQ, THF was found present in the product, 3-4 times above recommended level. The HPLC method in the Ph.Eur is 10 minutes, however, by increasing acquisition time, a radio peak appeared at about 18 minutes in the chromatogram. This peak was about 10-15% of total radio signal, meaning the required radio purity limit in Ph.Eur was not met. When analysing for enantiomeric purity, which was not initially done, about 12% of the d-enantiomer was found, not meeting the Ph.Eur limit. Increasing the flow of helium during the azeotropic distillation decreased residual solvent, and subsequently the ICH residual solvent limits was met. The radio peak in the HPLC was found to be methyl iodide (MeI) which is adsorbed and co-eluted from the C-18 Sep-Pak cartridges. Eckert and Ziegler proposed a rearrangement of the module tubing and a new synthesis template program enabling direct helium flushing of the C-18 Sep-Pak. By the use of this new configuration, removing excess MeI was achieved and the radio purity limits described by the Ph.Eur monograph was finally met. Different protocols are called for in the initial phase dissolving the precursor in ethanol and NaOH solution, however, tweaking these had little effect of the enantiomeric purity. Different batches of precursor was later analysed for enantiomeric purity. Large discrepancies were found between batches which directly influenced the enantiomeric ratio of the final product. Conclusion: Great care should be taken in the installment of new synthesis systems, and all available tests should be run before system installation is approved. The Ph.Eur. methods may not always be sufficient to prove radio or chemical purity, even if a monograph exist. Introduction: The interest in 68 Ga-tracers has been growing strongly over the last years, mainly due to new developments in prostate cancer imaging and therapy. 1,2 In collaboration with IBA, we have established an automated synthesis of 68 Ga-labelled peptides including 68 Ga-DOTA-TATE/-NOC, 68 Ga-PMSA-11 and 68 Ga-PSMA-617 on Synthera®. Materials and methods: During the tests, an IBA Synthera® and the new Synthera® Extension module were used. 68 Ga was obtained initially from an old iGG 100 generator in 5 mCi. The final tests were carried out in combination with a new GalliaPharm 68 Ge/ 68 Ga generator loaded with 50 mCi. A modified standard nucleophilic IFP TM (IFP™ FDG) was designed for the synthesis process. Synthera® Extension was used for the elution of the generator. The eluate was loaded on a Chromafix PS-H + cartridge and the hydrochloric acid waste -which contains most of the 68 GeCl 4 -was transferred into the waste container. The activity was eluted from the cation exchange cartridge using a solution of 5 M sodium chloride in 0.1 N hydrochloric acid 3 and transferred directly into the reaction vessel which was pre-loaded with precursor in 1.5 M HEPES buffer. Labelling was carried out at 95°C for 7 minutes. Purification was performed using a Sep-Pak® Light C18 cartridge. The product was eluted with a 1:1-mixture of ethanol/water and dispensed into the final vial through a sterile filter. Further dilution was performed with 0.9% saline by passing through the sterile filter. The peptides were synthesized in a GMP-compliant qualified area at ABX. For the DOTA-peptides, stock solutions were prepared (1 mg/ml) and freezed. For PSMA-11, vials with 10 μg of precursor were used. Results: With 50 μg of DOTA-TATE, DOTA-NOC and PSMA-617, the final radiolabelled products were obtained in >60% uncorrected yield. For PSMA-11, only 10 μg of precursor were used. The radiochemical purity was >98% in all cases. The Ph. Eur. spot test for HEPES was performed and showed HEPES < 200 μg/V with V being 12 to 14 ml. The pH of the final solution was 5 to 5.5. Ethanol content was < 10%. Discussion/conclusion: We have developed a dedicated disposable IFP cassette for the IBA Synthera® and Synthera® Extension modules, which delivers all common 68 Ga-tracers in high yield. The use of dedicated single -use Gallium-68 IFP TM allows for production of 18 F-FDG on the same module with no cross-contamination. Results: According to our knowledge, this is the first time that GMPproduction of 15 O labeled water using IBA 18 MeV proton cyclotron is described. The method was validated and met all pharmacopeia specifications, and was subsequently approved for patient studies. The practical production yield of 15 O labeled water using this method was ranged between 1300-1700 MBq measured in the syringe. This method is suitable for multiple batches within a time frame of 8 minutes. After validation more than 50 patient runs were performed with a reliability of > 99 %. Conclusion: A new production method for 15 O-labeled water using Cyclone 18 and dedicated chemistry module from IBA was described and qualified according to GMP regulations. It was demonstrated to be suitable for clinical use.

PP04
In Introduction: Cancer caused by abnormal cell proliferation has become a very common disease in recent years. Nuclear imaging has a significant place in cancer diagnosis. Photosensitizers (PS) such as chlorine, phthalocyanine, porphyrin and tetraprol derivatives are come up PDT applications. Furthermore, PSs accumulate selectively in the tumor tissue compared to normal tissue. Therefore, such compounds labeled with a radionuclide can be used as a probe for nuclear imaging. In present study, we synthesized a new Subphthalocyanine (SubPc) and Zinc phthalocyanine [Zn(II)Pc] and determined in vitro nuclear imaging potential. Materials and methods: SubPc and Zn(II)Pc were synthesized according to published methods of Ince et al.The radiolabeling with 131 I via iodogen method was carried out and optimization conditions (pH, amount of iodogen and reaction time) were determined. We will use EMT6/P (mouse mammary carcinoma), HeLa (human cervix adenocarcinoma) Hep G2 (human liver hepatocellular carcinoma), HT-29 (human colon colorectal adenocarcinoma), WI38 (human normal lung fibroblast) cell lines for the intracellular uptake studies. The intracellular uptake efficiency of 131 I labeled Pcs are determined according to published study of Ocakoglu et al. in mentioned cell lines.
Results: We observed that the radiolabeling efficiencies of SubPc and Zn(II)Pc were significantly high (91.9±3.1% and 97.2±1.4%, respectively). The optimization conditions were determined as pH 9, 1 mg amount of iodogen and 30 minutes of reaction time for SubPc; pH 7, 1 mg amount of iodogen and 45 minutes of reaction time for Zn(II)Pc. In vitro cell line studies are in progress.
Introduction: In recent years, photodynamic therapy (PDT) gained speed in cancer treatment. This method is based on two steps. Firstly, a photosensitizer (PS) is accumulated in cancer tissue then flowed by light irradiation. During a photoreaction Type II, energy transfer occurs between the PS and molecular oxygen (O2), the exposed photosensitizers produce highly toxic singlet oxygen (1O2). The singlet oxygen is responsible for the cell damage.1-3 Pthalocyanines have high tumor uptake efficiencies. This property allows them to be used as bifunctional agents for PDT and nuclear imaging. In the present study, symmetrical Zn(II)Pc 1 and unsymmetrically substituted Zn(II)Pc 2 were synthesized and examined as a bifunctional agent for nuclear imaging and PDT. Materials and methods: Zn(II)Pcs were synthesized according to a published procedure. 4 The Zn(II)Pcs were radiolabeled with 131I by using iodogen method. Optimization conditions of radiolabeling (pH, amount of iodogen and reaction time) were determined. Biodistribution studies were performed with Albino Wistar female healthy rats. The radiolabeled Zn(II)Pcs were injected into the tail vein of each rats and then the rats were sacrificed at 30, 60 and 120 min post administration. Tissue samples were collected and counted using a Cd(Te)-RAD-501 single channel analyzer. In vitro the photodynamic therapy studies, EMT6/P (mouse mammary carcinoma), HeLa (human cervix adenocarcinoma) cell lines were used. Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light (650 nm) at the doses of 10-30 J/cm2. Results: The Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabeled with 131I with high efficiency (93.4±1.6% and 91.4±1.6%, respectively). The results of biodistribution study showed that radiolabeled Zn(II)Pc 1 has high uptake on lung, large intestine, ovary and pancreas. However, the uptake of radiolabeled Zn(II)Pc 2 was determined as to be statically significant in pancreas and large intestine. Zn(II)Pc 1 was showed no phototoxic effect in both cell lines although PDT activity of Zn(II)Pc 2 in HeLa cell line was determined. Conclusion: In conclusion the radiolabeled Zn(II)Pc 1 might be a promising imaging agent for lung, ovary pancreas, and colon tumors. However, the radiolabeled Zn(II)Pc 2 might be a promising nuclear imaging agent for colon and pancreas tumors, also promising PDT agent for cervical tumors. Results: For best resolution and avoiding an excessive back-pressure to the PDA cell (<70 bar) the capillary between PDA and γ-detector should be as short as possible. This was realized by placing the γdetector in 30 cm distance to the PDA-detector on a special table. Three different flow cells were applied: a) Raytest standard flow cell (5 μL), b) Raytest 2" capillary holder equipped with a UPLC capillary 0.004" ID (9/5/2 nL), c) self-build lead insert with a 5 mm hole and UPLC capillary (2 nL). By injecting 400 kBq of [ 18 F]fluspidine and using the different flow cells, γ-signals having a peak width between 0.13 and 0.20 mm and a peak intensity 750 -4400 cps were obtained. The capillary holder (5 nL) and the self-build insert (2 nL) showed a comparable peak width, but differentiated sensitivity. To determine the minimum detectable level samples between 170 kBq and 8 kBq of [ 18 F]fluspidine were injected; with 15 kBq of [ 18 F]fluspidine a good signal to background ratio of 6:1 was achieved. Conclusion: By performing radio-U(HPLC) with a GABI Star γ-detector equipped with a Raytest 2" capillary holder (5 nL), γ-signals with good sensitivity and peak width can be obtained. In addition, the self-build flow cell insert (2 nL) gave the highest sensitivity and the best signal to background ratio. Introduction: Several studies are available, which highlight the use of Schiff based as ligands for radio-labeling, but very little work has been reported with Marcepto compounds. It is desirable to include such compounds in the design of radiopharmaceuticals due to their importance in the biological system. Materials and methods: Equimolar Lcysteine and salicylaldehyde in distilled water and ethanol were heated to form a white colored ligand. The product formed was analyzed using FT -IR, thermo gravimetric analysis and elemental analysis. Radiolabeling of the ligand was performed using 99m Tc from 99 Mo generator. SnCl 2 .H 2 O was used as a reducing agent. Radio TLC was performed using SG plates, 0.9% NaCl and acetone as the mobile phases. Geiger Muller counter detected the counts on the SG plates. After quality control the radiolabeled drug was injected IV into the animal ear. Scanning was performed under the gamma camera. Results: Ligand synthesis was verified from IR indicating the presence of the closed ring structure Thiozolidine ring 1 . IR showed absence of chromophore group hence the ligand was colorless. DSC peaks indicated the reaction type as endothermic. Ligand appeared to be stable in DMSO. Effective radiolabeling was achieved using lyophilized tin chloride pyrophosphate cold kit in NaCl (0.9%). Optimization of ph, temperature and radioactivity was done using DOE. Maximum radiolabeling was achieved at pH 5.Animal study was performed for bio distribution of the radiopharmaceutical. 99m Tcligand uptake was seen in the soft organs immediately after injection. The areas showing higher radiotracer uptake were kidney (20 %), liver (35 %), bones (15%) and brain (10 %). Delayed images showed the radiotracer retention in the soft organs as well as in the spine of the animals. Comparative study was performed using 99m Tc -MDP and 99m Tc PHYTATE. Conclusion: Salicylaldicysteine is efficiently labeled with 99m Tc and is suitable in simultaneous scanning of liver, kidney and brain. Due to uptake in all soft organs in dynamic flow followed with delay images, radiotracer retention in the brain is worth consideration. This indicates the ability of drug in crossing the blood brain barrier. This study also highlights the importance of sulfur containing ligands in brain scanning

PP08
Radiolabelling of poly (lactic-co.glycolic acid) (PLGA) nanoparticles with 99mTC R Iglesias-Jerez 1 , Cayero-Otero 2 , L. Martín-Banderas 2 , A. Perera-Pintado 3 , I. Introduction: Radiolabelled nanoparticles have gained a widespread application in the diagnosis and therapy of several diseases (inflammation/infection, cancer, and others). PLGA Nanoparticles (NPs) prepared by solvent emulsion evaporation method [1] have shown more suitable characteristics with regard to those produced by nanoprecipitation: better size, a higher homogeneity and higher encapsulation efficiency. The combination of 99m Tc + PLGA nanoparticles (platforms with excellent biodegradability and biocompatibility) could allow obtaining a suitable nanosystem for theranosis. The aim of the present work is to optimize the radiolabelling of PLGA nanoparticles with 99m Tc. Materials and methods: PLGA nanoparticles were prepared using the nanoprecipitation method [1]. Then, 5 mg of lyophilized NPs were dispersed in 1 mL 0.9% NaCl and stored in a vacuum vials. Different amounts of stannous chloride dehydrate in aqueous solution (30, 20, 4, 2, 1 and 0,1 μg) were added. Then, was added ≈74 MBq (2 mCi) of 99m Tc in 1 mL of 0.9% NaCl. Finally, the suspension was incubated for 10 min. 99m Tc -NPs suspensions were analyzed by thin layer chromatography (TLC) with silica gel strips (10 x2,5 cm). With 0.9% NaCl as the mobile phase, free pertechnetate ran with the front, meanwhile particles stayed in the start. Using a solution of pyridine: acetic acid: water (3: 5: 15), radiocolloids remained at start, NPs migrated with Rf = 0.3 and free pertechnetate moved with Rf = 0.7-0.8 [2]. Results: Using 1 μg of SnCl 2 *2H 2 O as a reducing agent, PLGA nanoparticles (without surface modification) were labeled with 99m Tc with a yield ≥ 90 %.PLGA nanoparticles size ranged from 160-180 nm in diameter with an electric surface of -36 mV. After radiolabelling, particles increased in size up to a diameter ≈ 380 nm. Conclusions: Results obtained, indicate that the procedures of nanoparticle synthesis, radiolabelling and quality control were reproducible and right to design a biodegradable nanosystem suitable for in vivo theranosis. Introduction: The Gastrin Releasing Peptide (GRP) receptor has high expression on prostate cancer cells. Consequently, bombesin, a 14-amino acid peptide that binds with high affinity to GRP receptors, has been widely studied for the development of radiopeptides for application in prostate cancer imaging. To overcome some limitations of radiolabelled peptides, we developed a small molecule non-peptidic radiotracer targeting GRP receptors. Small molecules offer various advantages over peptides since they can be suitably designed to modulate potency, selectivity, lipophilicity, and cell permeability and do not suffer from poor tissue penetration, poor serum stability, and quick elimination. The aim of the present study is to develop a non-peptidic fluorine-18 PET radioligand with antagonist properties, for visualization of GRP receptors. PD-410 ((S)-3-(1H-indol-3-yl)-N-[1-[5-(2-fluoroethoxy)pyridin-2-yl]cyclohexylmethyl]-2-methyl-2-[3-(4-nitrophenyl)ureido]propionamide) was selected as potent compound for 18 F-radiolabelling (K i was 38 ± 2 nM). Methods: [ 18 F]PD410 was synthesized by reaction of [ 18 F]fluoroethyl tosylate with the corresponding phenol precursor in presence of NaH followed by HPLC-purification. Cell experiments were carried out with PC3 cells to determine cell uptake, efflux and in vitro binding affinity. Results: In contrast to other [ 18 F]fluoroethylation reactions, RCY was low (<5%) because of substantial defluorination. The uptake of [ 18 F]PD410 in PC3 prostate cancer cells gradually increased within 60 minutes of incubation, thereafter reaching a plateau. The maximum cellular associated radioactivity was found to be 70%. Non-specific binding accounted for 40%. The efflux kinetics of [ 18 F]PD410 showed rapid dissociation of the tracer, remaining only 6% of the tracer within 120 min. This radioactivity decreased exponentially with a half-life of 13 minutes.  Materials and methods: The extent of 18 F-fluorination of labeling precursor was followed via radioTLC (EtAc:hexane 1:2). The HPLC purification was performed using Waters C18 XBridge 250 x 10 mm column, 0.05M NH 4 OAc:EtOH, 50:50, 3 ml/min, UV 254 nm. For SPE purification 1.2 mL of aqueous 25% EtOH was added to the reaction mixture (5 mg of precursor, 0.6 mL of DMF) to prevent precipitate formation. The resulting solution was passed through the Sep-Pak tC18 Plus Long cartridge. The cartridge was then rinsed with 2 mL of 50% aq. EtOH allowing for complete removal of the precursor. The product, [ 18 F]FEDMBT, was recovered by successive elution of the cartridge with 2 and 1 mL of 55% aq. EtOH. Results The [ 18 F]FEDMBT was prepared via direct nucleophilic fluorination of the corresponding tosyl precursor 1 . Under optimal reaction conditions (kryptofix 2.2.2., DMF, 140°C, 5 min) a high 18 F-incorporation rate of 80-85% was achieved. The HPLC purification afforded the product in >99% radiochemical purity and RCY of 55% (decay corrected). Isolated product fraction was mixed with phosphate buffered saline to adjust the pH and ethanol concentration, without final re-formulation step. Fractionated SPE purification afforded product with >99% RCP and 60% RCY (decay corrected). While SPE technique allowed for complete removal of precursor, a minor chemical impurity (not identified) remained in the final formulation. Work is being undertaken now to resolve this issue. Discussion/conclusion: An optimized synthesis of [ 18 F]FEDMBT afforded product with radiochemical purity and high yield. It can be easy automated using TracerLab FX-N Pro platform. The suggested "HPLC free" SPE purification can be applied in the production of  Introduction: 99mTc is the radionuclide most widely used in diagnostic nuclear medicine. It is available from 99Mo/99mTc generators, where 99Mo is obtained by a fission reaction in nuclear reactors. Direct reactions using proton beams [e.g. 100Mo(p,2n)99mTc] are a reliable and relatively cost-effective method to fulfill the shortage of this isotope given the imminent closure of the existing old reactors. However, the results of LARAMED project from the LNL-INFN showed that the extracted solution of 99mTc from the proton-bombarded 100Moenriched target contains small quantities of several technetium radioisotopes (93Tc, 94Tc, 95Tc, 95mTc and 96Tc) [1]. The aim of this work was to estimate the total contribution of technetium radioisotopes to the patient radiation absorbed dose after administration of four radiopharmaceuticals prepared with technetium-99m obtained from the 100Mo(p,2n)99mTc reaction. Methods: The internal radiation absorbed doses of pertechnetate, sestamibi, hexamethylpropyleneamine oxime (HMPAO), and disodium etidronate (HEDP) radiopharmaceuticals, were assessed considering both technetium-99m prepared from the 100Mo(p,2n)99mTc reaction as well as from generators. Time-integrated activity in the main source organs [Ã(rs,TD)] for each radioisotope was calculated using the radiopharmaceutical biokinetic models published by the International Commission on Radiological Protection (Publication 53 and 80, ICRP). OLINDA/EXM 1.1 software was applied for dose calculations using an adult male phantom as a program input and the above Ã(rs,TD) calculated values. The total absorbed dose in the target organs, produced by the mixture of technetium radioisotopes, was calculated for 3 time periods after 100Mo irradiation.
Results: The amounts of other technetium radioisotopes in the 99mTc-radiopharmaceuticals produced a low increase of radiation doses. Bone marrow is the organ that exhibited the highest difference between the dose obtained from the generator-produced 99mTc and the accelerator-produced one. For example, HEDP bone marrow dose (4.41E-03 mSv/MBq) showed an increase in the of 8.5% (4.79E-03 mSv/MBq), 11.8% (4.93E-03 mSv/MBq) and 17.7% (5.19E-03 mSv/MBq) using 99mTc obtained at 9, 14, and 19 h after 100Mo irradiation, respectively. The corresponding differences for sestamibi, pertechnetate and HMPAO were less than 8%, 10% and 14% for the same irradiation times. Conclusion: The increase of radiation doses caused by 93Tc, 94Tc, 95Tc, 95mTc and 96Tc, compared with the dose from 99mTc is relatively low. However, its impact should not be underestimated. Administering the labeled radiopharmaceuticals at least nine hours after the target irradiation is advisable to reduce the irradiation caused by the other technetium radioisotopes. Introduction: The use of pharmacokinetics modeling in preclinical nuclear medicine is very limited although it is well known that such models could be valuable tools to study radiopharmaceutical-properties1. Nowadays, the preclinical evaluation of new radiopharmaceuticals is still focused only on biodistribution studies, mainly because of the lack of currently available user-friendly specialized programs to assist researchers in calculating radiopharmacokinetic parameters. Methods: A dedicated spreadsheet software to calculate pharmacokinetic parameters such as tracer-biological half-life (T1/2), mean residence time (MRT) for each compartment, as well as the fraction of the tracer leaving the compartments per unit time (transfer rate constant, TRC), has been developed. The menu-driven spreadsheet software is based on five-Compartment Kinetic Model (CoKiMo). CoKiMo was used to study pharmacokinetic parameters of 11 99mTc-nitrido complexes, reported as potential myocardial perfusion-imaging agents (MPIAs), of general formula [99mTcN(DTC-Ln)(PNP)]+ (DTC-Ln= alicyclic dithiocarbamates; PNP= diphosphinoamine)2, and the results were compared with those of 99mTc-Sestamibi and 99mTc-Tetrofosmin. Biodistribution studies for all MPIAs have been performed in Sprague-Dawley rats (n = 312) to determine organ uptake. Results: MPIAs time-activity curves have been obtained using CoKiMo for 5 compartments, by interpolation of organ activity values measured at different time points. Curves have been integrated to calculate T1/2 and MRT in the studied organs of all MPIAs. Subsequently software employs a module with implemented optimization procedure, dedicated to calculate the values of the TRCs. Finally, CoKiMo calculations were validated by comparison with two different software: Olinda/Exm and SAAM II. [99mTcN-(PNP)]+-complexes showed a faster blood and liver clearance as compared to 99mTc-Sestamibi and 99mTc-Tetrofosmin, in agreement with some previous reported studies2. However, it was found that when CoKiMo pharmacokinetic data were used, a wide quantitative comparison between all MPIAs was possible, which in fact, was not possible using only the biodistribution data. The analysis of the results showed that 99mTcN-PDTC3 turned out to be the best candidate for translation into clinical practice due to its rapid and high heart uptake, and fast liver and lung clearance, which enabled an early visualization of myocardial tissue. Conclusion: CoKiMo proved to be an easy to use and flexible specialized software to study the kinetic of a great number of pharmaceuticals labeled with an unlimited number of radionuclides. Therefore, it can be a useful tool for an extensive preclinical characterization of new radiopharmaceuticals. Introduction: PEGylation is a methodology that is commonly used to improve the PK profile of radiotracers. In recent years biocompatible poly(2-alkyl-2-oxazoline)s (PAOx) gained a lot of attention as alternative to PEG because of their much higher chemical versatility. PAOx can be equipped with side-chain functionalities, allowing loading multiple targeting molecules, while the chain-end can be selectively radiolabeled. We previously evaluated the PK behavior of 89 Zr-labeled poly(2-ethyl-2-oxazoline)s ( 89 Zr-PEtOx) in a molecular weight (MW) range of 5-110kDa using μPET imaging. While we found the expected increase of circulation time with increasing MW, the 5kDa [ 89 Zr]-PEtOx demonstrated unusual high kidney retention. We now developed [ 18 F]-PEtOx 5kDa and compared its pharmacokinetic behavior to [ 89 Zr]-PEtOx 5kDa. Materials and methods: PEtOx was radiolabeled with 18 F using SPAAC. For this, PEtOx was first derivatized with bicyclononyne (BCN). Automated 18 F-labeling of BCN-PEtOx was performed by reaction of azidoethyl tosylate with azeotropically dried 18 Ffollowed by distillation of the formed [ 18 F]-fluorethylazide into a second reactor for reaction with BCN-POX. The reaction mixture was purified using a PD-10 cartridge and QC was performed using a Zenix-C 80Å column. To evaluate the PK profile, C57BL/6 mice (n=4) were intravenously injected with [ 18 F]-BCN-PEtOx (16.47±1.68Mbq,~100μg) and dynamically scanned over the first 2h. Volumes of interest were delineated for heart, liver and kidneys to calculate standard uptake values (SUV).
Results: [ 18 F]-BCN-PEtOx was obtained with a RCY of 4.30% (n=4, decay corrected to EOB) and a RCP of 100% after PD-10 purification. As was previously demonstrated for [ 89 Zr]-PEtOx 5kDa, μPET imaging revealed rapid and complete blood clearance of [ 18 F]-PEtOx 5kDa (SUV=2.42±0.16 at 10min pi and SUV=0.27±0.08 at 1h pi). Peak liver uptake related to perfusion was reached within 1min pi (SUV=2.92 ±0.18) and quickly decreased (SUV=0.50±0.03 at 10min pi and SUV=0.07±0.00 at 1h pi) indicating only minor contribution of the liver in the clearance of [ 18 F]-PEtOx 5kDa. The kidneys displayed a high initial uptake (SUV=5.67±0.87 at 3.75min pi versus 7.58±2.54 at 3.75min pi for [ 89 Zr]-Df-PEtOx 5kDa) but where [ 89 Zr]-Df-PEtOx 5kDa was not cleared from the kidneys (SUV=2.36±0.84 at 24h pi), [ 18 F]-PEtOx 5kDa showed a fast and almost complete clearance (SUV=0.27 ±0.08 at 1h pi and SUV=0.12±0.05 at 2h pi). Conlusions: [ 18 F]-PEtOx 5kDa is quickly cleared from the body and does not display high kidney retention. The unusual kidney retention of [ 89 Zr]-Df-PEtOx 5kDa is therefore most likely related to endocytosis and lysosomal degradation of the radiolabeled polymer followed by trapping of radiometal 89 Zr in the proximal tubules. Discussion/conclusion The nucleophilic fluorination of Ni II -based labeling precursor offers potential novel route towards a new derivative of DOPA with 18 F-label in the α-fluoropropyl group. Preparation of precursor employing methoxy methoxy (MOM) protective groups instead of mesyl ones, something that should resolve the deprotection problem, is currently in progress. This study was supported by SNF grant IZ73ZO_152360/1. Introduction: [18F]Clofarabine has recently emerged as a promising radioligand for in vivo imaging of deoxycytidine kinase activity using PET. In the reported protocols by Shu and Wu (1,2), 3 is prepared in a two-step process with an intermediate purification that proceeds with 10-15% radiochemical yield (RCY). We herein report a simplified procedure for the preparation of 3, in which the intermediate purification was eliminated. Materials and methods: [18F]Fluoride was produced using a GE PETtrace cyclotron and dried azeotropically with acetonitrile (MeCN), potassium carbonate and kryptofix (K2.2.2). Radiofluorination was performed in MeCN at 90 oC for 20 minutes, after which solvents were removed in vacuo and deprotection was performed using 10% trifluoroacetic acid (TFA) in dichloromethane (DCM) at room termperature (rt) for 5 min. Following an additional evaporation, the crude product was dissolved in mobile phase and purified using semi-preparative HPLC (ACE, C18, 5μm, HIL 250×10 mm, eluted with MeCN: aq. NH4OH (0.6%) 90.5:9.5 (v/ v) at 6 mL/min). 3 was isolated from the eluent using a C-18 SepPak cartridge (Waters) and formulated for intravenous injection in a solution of ethanol and phosphate buffered saline (10:90). Results: The radiochemical conversion (RCC) of 18F-fluoride into 3 was between 25-30%. Higher reaction temperatures or prolonged heating did not improve the RCC. Removal of MeCN from the reaction mixture prior to deprotection was found to be essential and may be ascribed to the known inhibiting properties of MeCN on trityl-group hydrolysis (3). By-product formation, sometimes observed when refluxing 2 with aqueous HCl, could be effectively eliminated by employing mild conditions for the deprotection (10% TFA in DCM, rt, 5 min) without compromising the RCY. No intermediate purification was required in the process, that produced >99% radiochemically pure 3 in 20% RCY with a specific activity >100 GBq/μmol. Discussion/conclusion: A simplified one-pot radiosynthesis of 3 was developed in which intermediate purification was eliminated. The RCY is on par with previously reported protocols for 3 synthesis. Introduction: In vivo imaging of estrogen receptor (ER) densities in human breast cancer is a potential tool to stage disease, guide treatment protocols and follow-up on treatment outcome. Among various techniques to detect ligand-ER interaction both positron emission tomography (PET) and fluorescence imaging have received ample attention. Materials and methods: In this study we use 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as a fluorescent probe and precursor for 18 F-labelling to develop estradiol-based ligands for ER. The synthesis involves attachment of a BODIPY moiety to the C17α-position of estradiol using Sonogashira cross coupling reaction of iodo-BODIPY and various 17α-ethynyl estradiol (EE2) derivatives. Confocal laser scanning microscopy was used to monitor cellular uptake of the EE2 conjugates after 1 h of treatment without and with estradiol to block ER. Flow cytometric analysis was performed to determine the relative fluorescence in the nuclei. The relative binding affinities to the estrogen receptors (ERα and ERβ) was assessed by a competitive radiometric assay. Results: The Sonogashira coupling reaction of EE2 derivatives with iodo-BODIPY(1:1 molar ratio) in THF/toluene (1/2) and using PdCl 2 (PPh 3 ) 2 as catalyst, NEt 3 as a base and CuI at room temperature gave the desired EE2-BODIPY conjugates in 45-86% yield (after purification by silica gel column chromatography). In vitro fluorescence imaging of the basic EE2-BODIPY conjugate confirmed ER-mediated uptake by the nuclei of ER-positive MC7-L1cells. Discussion and conclusion: The synthesis of a series of EE2-BODIPY conjugates was achieved via Sonogashira cross-coupling in moderate to very good isolated yields. Our in vitro nuclear cell uptake and receptor binding results warrant further studies to evaluate the potential of the EE2-BODIPY conjugates for fluorescence/PET imaging of breast cancer that overexpress ER. Fluor-18 labelling of the BODIPY moiety of the conjugate, and in vivo fluorescence/PET imaging studies, are in progress. has recently demonstrated its potential in individual first-in-man studies gaining importance above all in view of its theranostic application as it can be labelled also with 90-Yttrium and 177-Lutetium. In this study the two 68Ga-labelled radiotracers were synthesized using an automatic Modular-Lab Eazy synthesizer (Eckert & Ziegler) and the reliability of the system was validated to guarantee preparations of pharmaceutical grade. Materials and methods: The system was assembled with a disposable cassettes and the vials were filled with commercial precursors and ready to use pharmaceutical grade reagents. After clicking the start button the following steps were performed: a 1850 MBq GalliaPharm 68Ge/68Ga generator (Eckert & Ziegler) was eluted with 0.1 M HCl by a peristaltic pump by passing through a cation exchange cartridge into a waste vial. The cartridge was dried and the blocked activity was eluted with 0.55 ml of a 5.5 M HCl/5 M NaCl solution into the reaction vial pre-filled with 40 ug of precursor (PSMA-11 or PSMA-617) and 2.6 ml of Sodium Acetate/HCl/EtOH buffer. The reactor was heated at 110°C for 4 (PSMA-11) or 8 (PSMA-617) minutes. The mixture was diluted with 7 ml of 0.9 % NaCl solution and transferred into the final product vial by passing through a light CM cartridge and a sterilizing filter. Results: Both radiopharmaceuticals were produced in high yield. Starting from an activity of 700±20 MBq the radiochemical yield were 75.6±10 and 75.2±7 % for PSMA-11 and PSMA-617, respectively (n = 5) after 15 minutes. RCP was assessed by HPLC and was always > 98 % (for 68Ga-PSMA-11 the sum of the peaks of the two isomers was considered). All the preparations were sterile and the endotoxin content was < 0.5 EU/ml. Discussion/conclusions: The Modular-Lab Eazy synthesizer works with a new technology which uses a pressure distribution system to transfer the liquid instead of solenoid valves or stopcocks. A disposable, easy to assemble cassette allows the synthesis of 68Ga-PSMA-11 and 68Ga-PSMA-617 in high RCY and quality. Introduction: 89Zr has received considerable interest as a positron emitting radionuclide for immuno-PET imaging due to the excellent nuclear and physical properties. Recently we reported that fusarinine C (FSC) is a promising alternative chelator for 89Zrbased PET imaging agents, exhibiting superior stability and kinetic inertness as compared to 89Zr-desferrioxamine B ([89Zr]DFO). [1] Here we designed FSC derivatized chelators for 89Zr labeling which were expected to on the one hand improve the stability of 89Zr-complexes by saturating the 8 coordination sphere of 89Zr and on the other hand, reduce the number of functionality making it suitable for the conjugation to monoclonal antibodies. Materials and methods FSC(succ)2 and FSC(succ)3 were synthesized by FSC reacting with succinic anhydride, and FSC(succ)2AA was synthesized by FSC(succ)2 reacting with acetic anhydride. The complexation properties of FSC(succ)2AA and FSC(succ)3 with Zr4+ were studied by reacting with ZrCl4. For in vitro evaluation partition coefficient, protein binding property, serum stability as well as acid dissociation and transchelation studies of 89Zr-complexes were evaluated and compared with  Introduction: [ 11 C]CO 2 and [ 11 C]CO are undoubtedly highly versatile radiolabeling agents with many applications. The formation of [ 11 C]CO from [ 11 C]CO 2 has become convenient and difficulties have been overcome for its further implementation in radiochemistry. Likewise, many reactions are being explored and many applications are already possible. [1] However, there is still a need for expansion of the carbon-11 chemistry toolbox. We here present unprecedented Michael addition reactions with carbon-11 labeled synthons 1 -3 as Michael donors. Methods: The synthesis of [ 11 C]Methyl acrylate 1 was performed with [ 11 C]CO 2 by fixation in a Grignard reaction with vinyl magnesium bromide (0.16M in THF) and subsequent Fisher esterification under acidic conditions. Alternatively, a palladium-mediated carbonylation reaction with [ 11 C]CO [2] in the presence of tert-butanol or tritylamine with vinyl-halides afforded [ 11 C]Tert-butyl acrylate 2 and [ 11 C]Trityl-acrylamide 3. Michael addition reactions were performed with N-(diphenylmethylene)glycine tert-butyl ester 4 by adding the synthons to the reaction solution using TBAF as a base in DMSO. Synthon 1 was distilled into the reaction mixture. Synthons 2 and 3 were purified by solid-phase extraction and the Michael addition was performed at 100°C for 5 min, respectively. Results: The synthesis of 1 was successful with over 70% radiochemical conversion (RCC) and >95% radiochemical purity determined by HPLC. After screening and optimization 2 was obtained in 79 ± 10% and 3 in 73 ± 5% RCC. The subsequent conjugate addition yielded [ 11 C]N-(diphenylmethylene)-glutamic acid 5-methyl 1-tert butyl ester 5 in 90 ± 5%, [ 11 C]N-(diphenylmethylene)-glutamic acid di-tert butyl ester 6 in 93 ± 6% and [ 11 C]N-(diphenylmethylene)-glutamine 5-trityl 1-tert butyl ester 7 in 78 ± 3% RCC.

Conclusion:
The successful synthesis of 1 -3 has been achieved in good radiochemical yields. Furthermore, conjugate addition to 5 -7 is possible and we are currently working on expanding the variety of reactions with these small synthons.

PP21
In vitro studies on BBB penetration of pramipexole encapsulated theranostic liposomes for the therapy of Parkinson's disease Introduction: Brain penetration and targeting is hard due to complex structure with different barriers such as blood-brain barrier (BBB) with blood-cerebrospinal fluid (CSF) interface and CSF-blood interface. Although these tight and rigid barriers protect brain, they also prevent penetration of molecules, drugs and radiopharmaceuticals for diagnosis and therapy of many neurodegenerative diseases. Parkinson' s disease (PD) is assumed to be one of the most frequently observed neurodegenerative disease among geriatric disorders. PD comprises motor symptoms resulting from the death of dopamine generating cells in the substantia nigra. By using the imaging modalities such as single photon emission computed tomography (SPECT), the decline in the accumulation of specific radiotracer in the striatum can be detected. For PD treatment, limited brain penetration of drug is a major concern. Passively or actively targeted, nanosized drug delivery systems such as liposomes have different interests for either therapy or diagnosis. Recent studies generally depend on the development of new delivery systems, theranostics, in which diagnosis can be managed together with therapy by evaluating therapeutic effect. Materials and methods: Theranostic liposomes were formulated by polyethylene glycole (PEG) coated, nanosized, either neutral or positively charged, 99m Tc labeled for SPECT imaging and pramipexole encapsulated for PD therapy. Their characterization and in vitro release kinetics were evaluated. In vitro penetration of both formulations was evaluated in a BBB cell co-culture model. Results: Both neutral and positively charged liposomes showed proper characterization with about 10% encapsulation efficiency and around 100 nm particle sizes. All formulations fitted to the first-order release kinetics. Both formulations were found BBB permeable in cell culture studies with fluorescent images and fluorospectroscopy. Conclusion: Promising characterization and release profiles were obtained with theranostic liposomes for both diagnosis and therapy of PD. Both neutral and positively charged formulations found BBB permeable in vitro. In vivo animal studies are continuing to obtain more accurate data. (The authors thank to Abdi Ibrahim Ilaç for Pramipexole. This study was supported by the grant of TUBITAK, Project No: 112S244).

PP22
Factors affecting tumor uptake of 99mTc-HYNIC-VEGF165 Filippo Galli 1 , Marco Artico 2 , Samanta Taurone 2 , Enrica Bianchi 2 , Bruce D. Introduction: Angiogenesis promotes tumor growth and metastatization and its principal effector is the vascular endothelial growth factor (VEGF) secreted by cancer cells and other components of tumor microenvironment. Nowadays, many anti-angiogenic therapies have been developed and radiolabelled VEGF analogues may provide a useful tool to non-invasively evaluate the efficacy of such drugs. Aim of the present study was to radiolabel the human VEGF-A165 analogue with 99mTechnetium (99mTc) and evaluate the expression of VEGFR in both cancer and endothelial cells in the tumor microenvironment by nuclear medicine imaging and immunohistochemistry. Material and methods: The human VEGF-A165 analogue was radiolabelled with 99mTc using succinimidyl-6-hydrazinonicotinate hydrochloride as a bifunctional chelator. In vitro quality controls were performed to assess its retained structure and biological activity. In vivo studies included biodistribution studies and tumor targeting experiments in athymic nude CD-1 mice bearing xenograft tumors from ARO, K1 and HT29 cell lines. Immunohistochemistry was performed on excised tumors to evaluate VEGF and VEGF receptor (VEGFR) expression in the lesion and endothelial cells. Results: The analogue was labelled with high labelling efficiency (>95%) and high specific activity, with retained biological activity and structural integrity. Tumor targeting experiments revealed a focal uptake of radiolabelled VEGF165 in tumor xenografts with different tumor-to-background ratios. Immunohistochemical analysis tumors revealed an inverse correlation between VEGF and uptake of the radioactive hormone. A positive correlation between radioactive VEGF165 and VEGFR1 was also observed. Conclusion: Radiolabelled human VEGF-A165 is a promising radiopharmaceutical to image angiogenesis and evaluate the efficacy of anti-angiogenic drugs. However, VEGFR imaging may suffer from quenching effects of endogenous VEGF produced by cancer and other cells of the microenvironment.  Introduction: Among radioisotopes for targeted therapeutic applications, 188Re is very promising, thanks to its suitable properties (βemitter, Emax = 2.12 MeV, t1/2 = 17 h, γ-emission of 155 keV, conveniently obtained through a generator), and to the fact that it is a homologous element to 99mTc, the radioelement of choice in nuclear medicine. Inside the "Vectorisation & Radiotherapy" Axis of the Canceropole Grand Ouest and the IRON Labex, our teams have developed a strong expertise on the chemistry and targeting of rhenium labelled radiotracers, from bench to bedside. Some examples of what we have been developing are given below. 188Re-labelled Lipiodol: We have developed a stable and efficient labelling of Lipiodol with 188Re as a potential treatment for HCC. A phase 1 clinical trial is currently running. 188Re-labelled particles: 188Re has been used to label micro-and nanoparticles. Radiolabelled starchbased microspheres are investigated in HCC, while lipid nanocapsules, also investigated in HCC and adenocarcinoma models, gave prominent results in glioma, for which transfer to clinic is underway. 188Re-labelled peptides: We are also developing a new bifunctional chelate for the Re(I) tricarbonyl core, able to link a biomolecule (peptide, protein…). Conclusions: For more than 15 years, our teams, working closely together, have developed a series of potential therapeutic radiotracers, some of which are now investigated in man, or about to be. Introduction: PET molecular imaging and receptor binding peptides are emerging as powerful tools for imaging. Somatostatin analogues labeled with 68Ga are the most widely used and have proven useful for the management of patients with neuroendocrine tumors. However, within the past few years several other receptor binding compounds labeled with 68Ga have shown promising results with potential clinical applications in PET centers that lack in site cyclotrons. The aim of this study was to develop a single vial kit solution for the production of 68Ga radiopharmaceuticals for clinical applications. Materials and methods: Chemical precursors DOTA-NOC, DOTA-RGDfK dimer, DOTA-Ubiquicidin (29-41), and PSMA-11 were acquired from ABX. Gallium-68 was obtained from an ITG generator while labeling was performed in an iQS module (ITG GmbH). Stock solutions of different concentrations were prepared by dissolving the precursors in 0.25M NaOAc. Aliquots of 100 μl of the stock solutions were dispensed in Eppendorf vials and stored at -20°C. For labeling, the aliquots were diluted with 900 μl of 0.25M NaOAc, mixed with 4 ml of 68GaCl3, and incubated for 10 min. Purification was made by SPE eluting the product with 1ml 50% EtOH. Final product was diluted with physiological saline and sterilized by filtration (0.22 μm, Millex-GV). Radiochemical purity (RCP) was determined by gradient HPLC using a Nova-Pak C18 column (3.9 x 150 mm), 2.5 ml/min flow rate. Eluents were A=0.1N TFA and B=MeCN. Results: Non-decay-corrected yields (mean±SD, n=10) were 60±12, 61±6, 56±10 and 70±10% for NOC, RGD, UBI and PSMA, respectively. RCP was >98% for all the radiopharmaceuticals. HPLC retention times were 0.5±0.1 min and 2.5±0.2 min for free 68 GaCl 3 and labeled compounds, respectively. No 68 Ge was detected in the final product. Conclusion: This labeling method using a single vial kit solution is simple, efficient and reliable, suitable to be used for the production of a variety of 68Ga radiopharmaceuticals for clinical diagnostic applications. Introduction: The clinical demand for 68Ga-labelled peptides is constantly rising, but the achievable radioactivity per batch is limited by the inventory of the 68Ge/68Ga generator. One possible approach to raising the radioactive yield is to merge the radioactive contents of two 68Ge/68Ga generators for one batch of 68Ga-peptide. The key to this method can found in frame with the cationic purification (1) merging two generator eluates. Our aim was to establish this method in the synthesis of 68Ga-DOTANOC. Material and methods: The experimental setup considered two 1.85 GBq (50 mCi) iThemba 68Ge/68Ga-generators with calibration Feb/15 and Oct/15 and a Scintomics GRP synthesis module. SC-01 peptide cassettes including the reagents were applied in the synthesis of 68Ga-DOTANOC. The automatic synthesis sequent was modified by us as followed: After the initial conditioning of the C18-SPE with ethanol, water and subsequent drying with N2 the "older" 68Ge/ 68Ga-generator was eluted with 7 mL 1M HCl by the motor syringe. 10 mL water was added for dilution, and the mixture was transferred over a PS-H+ SCX column (Machery-Nagel). The sequent stopped for the manual change of the generator tube. After continuing the sequent, the "newer" Generator was eluted in the same manner as described above. Once washing and drying the valve seats, 68Ga was delivered from PS-H+ into the reaction vessel with a solution of 1.4 mL 5M NaCl and 0.2 mL 6M HCl. The further labelling with 40 μg precursor in HEPES were performed as usual. Results: We found in our preliminary experiments more the 98% of the theoretical 68Ga radioactivity after "double elution" adsorbed on the PS-H+ SCX cartridge. About 15 % of 68Ga retained on the PS-H+ SCX after transfer of the 68GaCl3 into the reaction vessel. The followed labelling of 68Ga-DOTANOC revealed an uncorrected yield of >40%. Conclusion: The promising preliminary results with a yield of 1.1 GBq 68Ga-DOTANOC (EOS) in a merging operation of an "old" and a "new" 68Ge/68Ga generator indicates a high potential for improvement in routine preparation. Therefore, we extend our synthesis system with an additional valve actuator unit, which should handle the 68Ga elution from both generators automatically and under GMP conditions.  (1). This limit test is performed by TLC and developed by the exposing to iodine vapour. Alternatively, an HPLC method for HEPES has been published (2). Our aim was to approve this method of the quality control of 68Gapeptides. Material and methods: 68Ga-peptides (68Ga-DOTANOC, 68Ga-DOTATOC, 68Ga-DOTATATE) were synthesised with a Scintomics GRP synthesis module using SC-01 cassettes. The determination of HEPES was performed by HPLC Agilent 1260 equipped with a DAD detector on an Obelisc N column (4.6 x 150 mm, Sielc Technologies): isocratic eluent 20% ACN/80% water/0.05% phosphoric acid; 0.8 mL/min; UV detection at 195 nm. Results: Due to the polar characteristic of the Obelisc N column, a good separation of the sulfonic acid HEPES was achieved with a retention time of about 9 min. A system suitability test with a solution of 100 μg/mL HEPES and 1 μg/mL gentisinic acid was introduced. The analysis method was successful validated according to ICH in a concentration range of HEPES from 10 μg/mL to 200 μg/mL. This assay of HEPES was applied effectively in the *Theoretical starting activity of both 68Ge/68Ga-generator corrected to elution start of the second one refinement of synthesis sequence to the 68Ga-peptides. The accurate measurement of HEPES did help us to optimise the automatic workup of the reaction mixture via C18-SPE, that we reach an HEPES content in the final solution below 10 μg/mL routinely. A disadvantage of the Obelisc N is that the HPLC column is very sensitive to alcohol and neutral media. To avoid damage, for the Obelisc N column an acid media of about pH 2 must use to store. Otherwise due to irreversible deactivation of groups on the column material the signals of NaCl from the sample will shift in the retention time and interfere with the signal of HEPES, which disables the interpretation of the analyse results. Conclusion: We have demonstrated that HEPES impurities in 68Gapeptides can analyse by HPLC with respect to the limit of the European Pharmacopoeia. We validated this analysis method and used it in the development of the preparation of 68Ga-peptides. The HEPES determination by HPLC replaces in our laboratory the test by TLC and is integrated into the parametric release of our routinely prepared 68Ga-peptides. Materials and methods: 99mTc(I)-L complex was prepared by a two-step procedure involving the preparation of the precursor [99mTc(CO)3(H2O)3]+, followed by the addition of L. The labelling efficiency and challenge with histidine and cisteine were determined using gradient HLPC. The in vitro stability of the radiochemical complex was determined in saline and human plasma. TCA precipitation method for determining the percentage of complex bound to proteins was very useful. Lipophilicity measurements were done by solvent extraction method with noctanol. The overall complex charge was determined by electrophoresis on paper strips (Whatman no. 1) after exposure to a constant voltage (300 V) in phosphate buffer (pH 7.4) for 1 h. Organ distribution studies were carried out on normal and tumor-bearing mice (c57). Results: Radiolabeling yield was higher than 98% and remained high and practically unchanged at 24h post-labeling. 99mTc(I)-L complex was stable and resistant histidine challenges. The percentage of protein binding was 19.62±2.02%. It showed a lipophyilic character. Biodistribution data, 5 min post injection, showed a very high uptake in liver and intestine. The majority of the radioactivity of 99mTc(I)-L complex was eliminated via the liver into the intestine. The organ distribution in B16-melanoma-bearing mice showed increase in uptake by the tumor.
Discussion/conclusion: 99mTc(I)-L complex revealed high radiochemical purity and stability in vitro, without any measurable decomposition. A significant difference of 99mTc(I)-L complex uptake between melanoma model and the normal mice was observed. Biodistribution studies showed high tumor uptake in B16-melanomabearing mice. This study indicates that 99mTc(I)-L complex may be a potential agent for melanoma detection. Introduction: The synergistic interaction between hyperthermia and radiation therapy is based on the heat effect that may make some cancer cells more sensitive to radiation or harm other cancer cells that radiation cannot damage. In the present work two different types of magnetic nanoparticles (MNPs), Fe3O4-Naked and polyethylene glycol 600 diacid functionalized Fe3O4 (Fe3O4-PEG600), were synthetized in order to compare their efficiency as radioactive vectors. They were 90Y-labeled for the potential use in localized hyperthermia-radionuclide therapy. Materials and methods: MNPs were synthesized by co-precipitation of ferric and ferrous salts in a basic solution. Radiolabeling was performed by mixing 0.5 mL of aqueous Fe3O4-Naked and Fe3O4-PEG600 MNPs suspension with 37 MBq 90YCl3 (0.001 mL) and incubating at room temperature on a shaker for one hour. Radiolabeled particles were then separated from free 90Y activity by precipitation with the help of permanent magnet. Radiolabeled MNPs were further used for in vitro stability studies in saline and human serum, and in vivo biodistribution studies in normal Wistar rats. Discussion/conclusion: The Fe3O4-PEG diacid MNPs showed high phase purity and favorable physicochemical and magnetic characteristics for in vivo use. The obtained SPA value for Fe3O4-PEG diacid MNPs (200 W/g) indicates that these MNPs could be used as heating agents for in situ magnetic fluid hyperthermia protocols. Besides, high labeling yield (97%) and in vitro and in vivo stability of 90Y-labeled-PEGylated magnetite nanoparticles create opportunities for their use in the combined radio-hyperthermia cancer treatment.

Materials and methods:
The generator outlet is connected to an unmodified FDG-type disposable cassette with the appropriate reagent set and loaded onto the synthesizer. Once the automated process is started, vacuum elution takes place using only 1.1 mL of a 0.1 M HCl solution from the generator integrated reservoir. No purification being required, Ga-68 activity is directly sent to the reaction vessel.
DOTA-NOC labeling is conducted as follows: a solution of 50 μg peptide in 1 mL 250 mM acetate buffer at pH 5 is added and the mixture is heated at 120°C for 5 min. The reaction bulk is then loaded on an HLB cartridge and washed with 10 mL of water. 68Ga-DOTA-NOC is then eluted with 1 mL of EtOH/water 65:35 v/v mix followed by 1 mL of saline 0.9% and collected through a 0.22 μM Millex®-GV filter into a sterile vial containing 8 mL of saline 0.9%. PSMA-11 labeling is conducted as follows: a solution of 10 μg peptide in 1 mL 1.5 M acetate buffer at pH 4.5 is added and the mixture is heated at 95°C for 5 min. The reaction bulk is then loaded on a Sep-pak® Light C18 cartridge and washed with 10 mL of water. 68Ga-PSMA-11 is then eluted with 2 mL of EtOH/water 1:1 v/v mixture followed by 2 mL of phosphate buffered saline (PBS) and collected through a 0.22 μM Millex®-GV filter into a sterile vial containing 6 mL of PBS.
Results: 68Ga-DOTA-NOC is produced in r <20 min with 81.5±5.2 % radiochemical yield (RCY) (decay-corrected-d.c.) and 68Ga-PSMA-11 is produced in 13 min with 97.4±2.5 % RCY (d.c.). Reported process times include generator elution and formulation. In both cases, final products show high radiochemical purity (TLC > 97 % and 99 % respectively). Discussion/conclusion: Automated processes for the production of both 68Ga-DOTA-NOC and 68Ga-PSMA-11 have been successfully achieved using a commercial synthesizer and a 68Ge/68Ga generator. The labeling procedures are straightforward and efficient, thanks to the low elution volume and high purity of the generator eluate (no need for fractionation or post-elution purification). Introduction: Mono-product facilities are turning to multi-product to cope with decreasing prices of [18F]-FDG (FDG) and to support R&D programs. The aim is to demonstrate that in the same facility and equipment, a busy research program can be safely integrated into commercial production. Materials and methods: To be able to safely combine both activities a risk-assessment should be designed to identify key control points. The use of a fully automated platform (e.g. IBA Synthera) and its disposable cassettes can prevent human errors, reduce risk of crosscontamination and improve reliability. A production schedule, training and labeling procedures should also be considered. . BV Cyclotron VU in Amsterdam is a private company with a GMP-compliant PET production facility. Since the 90's FDG is delivered for the Dutch hospitals (annual output of > 7300 patient doses (11 TBq)). FCH and FBB (Florbetaben) are also commercially produced with annual output >1400 (1.7 TBq) and >340 patient doses (1.1 TBq), respectively. Besides the commercial productions there is also room for an R&D program, e.g., currently improvement of the production of FCH is examined.
Discussion/conclusion: As a conclusion, the sites described have been functioning for several years and are able to safely combine commercial daily production while keeping a highly active R&D program with more than ten different tracers developed for pre-clinical and clinical applications. Introduction: There is a continued interest for development of radiolabeled RGD peptides as integrin αvβ3 receptor targeted molecular probes possessing favorable pharmacokinetic behavior.1,2 In this study, two click chemistry modified cRGDfK peptide analogues have been synthesized 3 and radiolabeled with [99mTc(CO)3(H2O)3]+ precursor. Comparative in vivo evaluation of the two radiotracers was carried out to determine the pharmacokinetics and integrin αvβ3 targeting potential. Materials and methods: cRGDfK was functionalized with N3CH2COOH and N3PEG7COOH at ε-amino group of lysine. The two azidemodified derivatives (with PEG7and without) were then clicked with propargyl glycine to introduce a tridentate chelating unit for radiolabeling with [99mTc(CO)3(H2O)3]+ precursor. The radiotracers, 99mTc(CO)3-Pra-Tz-CH2-cRGDfK and 99mTc(CO)3-Pra-Tz-PEG7-cRGDfK were analyzed by HPLC. Analogous rhenium complexes were synthesized for characterization of 99mTc(CO)3labeled radiotracers. Biodistribution study of the two radiotracers was carried out in C57BL/6 mice bearing αvβ3-positive melanoma tumors. The radioactive preparation (~3.7 MBq/animal, 100 μL) was injected intravenously through the lateral tail vein. At different time intervals after injection (30, 60, and 180 min), the animals (n = 4/time point) were sacrificed and the relevant organs excised for measurement of retained activity. Results: The two radiotracers, 99mTc(CO)3-Pra-Tz-CH2-cRGDfK and 99mTc(CO)3-Pra-Tz-PEG7-cRGDfK were prepared in >90% radiochemical yield and exhibited excellent stability in saline as well as in serum. Maximum tumor uptake was observed at 30 min p.i. for the two radiotracers and was higher for 99mTc(CO)3-Pra-Tz-PEG7-cRGDfK (4.11 ± 0.51 %ID/g) as compared to that for 99mTc(CO)3-Pra-Tz-CH2-cRGDfK (3.01 ± 0.77 %ID/g). Tumor accumulation of both the radiotracers reduced to 50-60% during blocking studies with cold cRGDfK peptide, suggesting receptor-mediated uptake of radiotracers. Conclusion: The two neutral 99mTc(CO)3 radiotracers prepared exhibited receptor mediated uptake in melanoma tumor. Increased tumor uptake on introduction of PEG7 unit was compromised with slow clearance from other organs. Further modification of the peptide with a different spacer or a smaller PEG unit may lead to more favorable pharmacokinetics. Introduction: The shortage of 99Mo (fission) has renewed interest in alternative technetium-99m production methods either in nuclear reactor starting from 98Mo or in accelerator with 100Mo as a target material. Adsorption chromatography on alumina is not sufficient for alternative production methods due to high amount of Mo in the dissolved target solution. Several chromatographic resins were described for the separation of pertechneate from molybdate including Dowex or ABEC. Here we focused our attention on application of AnaLigTc-02 resin for efficient recovery of 99mTc from large molybdenum excess. Methods: To simulate a target dissolution mixture, 10 mL of sodium molybdate solution and a small amount of Na99mTcO4 in NaOH or (NH4)2CO3 was delivered on the column containing 100 mg of AnaLig resin using the flow rate of 0.4 mL/min. Before 99mTc elution, the column was fed with 3 mL of sodium hydroxide or ammonium carbonate solution and subsequently with 1.5 mL of water. The 99mTc was recovered in 5 mL of water. The eluate and other effluents activities (one after introduction of Mo solution and two after rinsing columns in term with NaOH or (NH4)2CO3 solution and water) were measured with the dose calibrator Capintec CRC-55tR. The sorption yield was studied as a function of NaOH and (NH4)2CO3 for concentration of 1.05, 1.4, 2.8 and 4.2 M for the former and 0.5, 1.5 and 2.5 M for the latter. Results: Best 99mTc recovery was obtained in 2.8M NaOH or 1.5M (NH4)2CO3 solution. Under these conditions, more than 86% adsorption and elution were achieved. Most 99mTc losses occurred during rinsing the column with water, even approaching 10% of activity and due to rinsing the column with NaOH or (NH4)2CO3 after sorption Tc-99m on Analig resin (up to 3.5%). The activity retained on the column was around 1% for solution in NaOH and about 3% for (NH4)2CO3, respectively. . The use of this radioligand as a clinical marker is highly dependent on the robustness of the radiochemical process used for its preparation.
[18F]FECNT has been previously synthesized in a two-step chemical process with 16% decay-corrected yield in total time of 150 min. Recently, more effective (25-33% decay-corrected yield, 80-90 min) one-step synthesis of [18F]FECNT by direct nucleophilic [18F]fluorination from N-mesyloxy precursor was reported in literature. However, the use of a mesylate as a leaving group in such a nucleophilic substitution reaction has some drawbacks. Mesylates are rather hard to detect using UV-absorption, which complicates the final HPLC purification of the radiotracer and also characterized by higher susceptibility to decomposition. Herein, we reported a fully automated synthesis of [18F]FECNT from the chlorinated precursor, which was earlier found to be the most stable of the studied halo-and sulfonyloxy-analogues. Materials and methods: The commercially available SynChrom [18F] R&D synthesis module was readily configured for the one-step synthesis according to conditions achieved for the fluorination with non-radioactive fluoride. The radiolabelling process involved a classical [18F]fluoride nucleophilic substitution from the chlorinated precursor (5mg) was performed at 110°C for 12 min. Crude product was purified using preparative HPLC and SPE methods. Results: The obtained yields for a chlorine-for-[18F]fluorine substitution of 59±12% (n=5) were higher than those (45-48%) reported for the [18F]FECNT batches prepared from the N-mesyloxy precursor. The total synthesis time was 80-90 min and [18F]FECNT batches of about 2.0±0.5 GBq (n=3) with high radiochemical purity over than 99% were obtained with 32±7% overall decay-corrected yields. These yields were comparable with previously reported results for the onestep synthesis of [18F]FECNT and significantly higher than yields obtained in two-step syntheses [2]. The specific activity of the final [18F]FECNT product was 55 GBq/μmol, which is consistent with literature synthesis results (38-72 GBq/μmol) of this radiotracer and sufficient for the DAT density determination in the human PET imaging studies. Discussion/conclusions: In this study, the new chlorinated precursor was successfully used for one-step automated radiosynthesis of [18F]FECNT. Considering these promising results as well as longterm storage stability of this precursor, reported procedure may provide a straightforward and reliable method for the production of radiotracer suitable for human use. Introduction: The in-time diagnosis of bacterial infection is extremely significant for the accurate treatment. Nuclear medicine scintigraphic imaging is an excellent non-invasive method of whole-body scanning, allow to determinate infectious foci in all parts of the body, based on pathophysiological changes which occur earlier in the infection process. The aim of this study was to perform gamma scintigraphy studies with bacterial infected and sterile inflamed rats with newly developed radiopharmaceutical 99mTc-amoxicillin sodium (99mTc-AMOX). Method: E.coli suspension was intramuscularly injected into the right thigh muscle of rats to create infection model. Turpentine oil was intramuscularly injected into the left thigh muscle of rats to create sterile inflammation model. After the infection and sterile inflammation focus were allowed to develop for 24 hours swelling appeared and gamma scintigraphy studies were performed. 99mTc-AMOX (3.7MBq) was intravenously injected via tail vein to the rats. After administration of radiopharmaceuticals, serial static images were acquired at different time intervals (5 minutes, 1, 2, 3, 4 and 5 hours post injection). Results: The uptake of 99mTc-AMOX following intravenous administrations was assessed on static images. The images depicted rapid distribution throughout the body and uptake in the bacterial infected and sterile inflamed thigh muscle within one hour after injection. There was a higher activity in both bacterial infected and sterile inflamed thigh muscle as compared to healthy thigh muscle. For quantitative evaluation, regions of interest were drawn around the target (infected and inflamed thigh muscle) and non-target (healthy thigh muscle) regions of the rats. The 99mTc-AMOX uptake was calculated by dividing the average counts per pixel within the region of target to the average counts per pixel within the region of non-target. Conclusion: Based on the in vivo studies, 99mTc-AMOX has higher uptake in infected and inflamed thigh muscle than healthy muscle. The data suggest that 99mTc-AMOX remained at the infection and inflammation foci during the whole experiments, there being no statistically significant differences in the ratios during the studied period (p≥0.05). Introduction: Infection detection by nuclear medicine imaging techniques based on pathophysiological changes which appear much earlier than anatomical changes in the infection process (1,2). To develop a better infection imaging which will accumulate efficiently to inflammatory foci, clear rapidly from background tissue, discriminate between bacterial infection and sterile inflammation, cost low and prepare easily we labeled amoxicillin sodium (AMOX) with 99mTc. The aim of this study is to prepare 99mTc-AMOX in a simple method with good labeling efficiency and evaluate the ready to use cold kit formulation thus making it available to the other nuclear medicine centers. The stability of 99mTc-AMOX in human serum was identified; sterility and pyrogenicity of the radiopharmaceutical was estimated. Method: To investigate the optimum radiolabeling conditions, radiolabeling was tested with different concentrations of reducing (stannous chloride and stannous tartrate) and antioxidant (ascorbic acid) agent. Radiochemical analysis was performed with Radio Thin Layer Chromatography (RTLC) and Radio High Performance Liquid Chromatography (RHPLC) studies. Two different freeze dry kits were formulated with optimum labeling conditions and stability, sterility and pyrogenicity of the kits were performed. Results: The effect of reducing agent concentration on the radiochemical purity was evaluated and optimum reducing agent amount found 200 μg. Under these conditions labeling efficiency was around 90%. In the presence of ascorbic acid, stability of the complex was slightly increase while labeling efficiency for early hours was not affected significantly. According to the experiments, the formation of the 99mTc-AMOX complex was very fast and reached the radiochemical purity over 95 % in 15 min after radiolabeling. While keeping other reaction conditions constant and varied the pH of the reaction from 4.8 to 7.4 radiochemical purity was slightly decreased. 99mTc-AMOX was found stable during to 24 hours incubation in saline and human serum. Kits were labeled with 37MBq, 185MBq and 370 MBq 99mTc. Slightly decrease in radiochemical purity was observed with increasing of radioactivity. According to sterility test, since there was no growth in batches, kits were sterile. Also gel clot test showed that kits were pyrogen free. The freeze dry kits developed in this study were found to be stable with a shelf-life of six months when preserved at both at +5 ±3°C and +25±2°C/60 ±5% RH. Conclusion: Simple method for radiolabeling of AMOX with 99mTc has been developed and standardized. Labeling efficiency of 99mTc-AMOX was assessed by both RTLC and RHPLC and found higher than 90%. The resulting complex was quite stable and labeling of ˃90% was maintained for up to 6 hours. Two different freeze dry kits was developed and evaluated. Based on the data obtained from this study, both products was stable for 6 months with high labeling efficiency.  and 170°C Experiments were repeated in acetonitrile, dimethylsulfoxide, tert-butanol and different P1:P3 ratios (1:1 and 1:5). Products were purified by distillation and analyzed (radio-TLC, radio-HPLC). Factor-H was reacted with an azido-(PEG)4-carboxylate linker (azido-PEG) targeting protein amino groups. Factor-H (1.6nmol in 250μl of pH 9 PBS buffer), was reacted (4h at RT) with 48nmol of NHS-activated azido-PEG. The azido-protein was purified by ultracentrifugation, suspended in water and lyophilized. 5- Introduction: Production of 18F-flumazenil from 2-nitroflumazenil under GMP conditions is primarily performed with manipulators or custom built radiosynthesis modules with fixed components, as the use of N,N-dimethylformamide (DMF) at 160°C prohibits the use of commonly available disposable cassettes. Cassettes for the GE TRA-CERlab MXFDG synthesis modules are commercially available in different materials. ROTEM Industries and GE Healthcare use polysulfone as the main component, and it is known that this polymer is not compatible with DMF. Cassettes from ABX are reportedly more chemical resistant, with polypropylene as its main constituent. The aim of this work was to establish a robust automated radiosynthesis procedure for 18F-flumazenil on the GE TRACERlab MXFDG, where staff previously trained on the same equipment can easily perform the radiosynthesis. Materials and methods: Fragments of the ABX FDG cassette were exposed for 1 or 24 h to various solvents including acetonitrile and DMF at room temperature (RT) or 60°C to assess its chemical resistance. A new synthesis sequence was written for the GE TRACERlab MXFDG. A non-radioactive test run was performed with the ABX FDG cassette, and radiosynthesis was carried out with the cassette components replaced by chemically resistance manifolds (ABX). Results: Incubation of the PP ABX FDG cassette fragments in acetonitrile at RT showed no macroscopic influence on the polymer while the fragment became soft and mouldable at 60°C. Visible changes occurred after 1 h incubation with DMF, with the polymer having completely dissolved after 24 h, regardless of temperature. To verify the implication of these results on a 1 h radiosynthesis, a test run was performed using the same cassette material and synthesis conditions without radioactivity. Parts of the manifold was found to have cracked, and a valve blockade was observed due to polymer melting. Radiosynthesis was carried out with the manifolds replaced by chemically resistant ones, and 18F-flumazenil was successfully obtained in 4 % decay corrected yield.

PP36
Conclusions: Disposable cassettes assembled with chemically resistant manifolds is a requirement for the automated synthesis of 18Fflumazenil from 2-nitroflumazenil using the GE TRACERlab MXFDG synthesis module. Neither reagent kits nor program sequences are hitherto commercially available, but GMP grade production can nonetheless be successfully carried out with modifications on existing equipment.

PP39
The Introduction: Targeting short peptides are gaining interests in the molecular imaging field. Choosing the radioisotope to label those peptides is a challenging stage in the process of identifying the right imaging modality. Method: All needed reagents and solvents were used with no further purifications unless it's necessary. Peptide used was purchased from GenScript and used without further purifications. Reaction progress was monitored using both radio-analytical thin-layer chromatography (Radio-TLC) and high pressure liquid chromatographic (Radio-HPLC). Radio-HPLC analyses were carried out on semi-preparative Phenomenex C-18 (250 mm x 10 mm). Radiolabeled peptide was detected with the eluting of 0.065% TFA in water and 0.05% TFA in MeCN at 2 ml/min applying gradient elution mode. Radiochemical yields were calculated based on the Radio-HPLC collections. Sodium Citrate Buffer (PH=7.5) wa the Radio-TLC mobile phase. Synthesis of DOTA-Peptide Conjugate: 9.97 E-7 mol of the intended peptide dissolved in DMSO reacts with 1.18 E-6 mol of (DOTA-NHS-ester) that was prepared in MeCN. The reaction was done in a phosphate buffer with PH=8 and heating at 90°C for 30min. 68G -labeling of DOTA-Peptide: 68G solution was added to 60 μg of conjugated DOTA-Peptide in 100 μl of HEPES buffer (PH=4) and the mixture allowed to react for 30 min at 80°C. Result: [68G-DOTA-Peptide] was analyzed on Radio-HPLC; the ration time of the product was 8.4 min and Radio-TLC checks for the collected product confirm the high radiochemical purity. Discussions: The labeled peptide is produce in good radiochemical yields and high radiochemical purity. Initial biological works are ongoing to evaluate its imaging potential mainly on a melanoma cell line. The findings will be presented.

PP41
Is validation of radiochemical purity analysis in a public hospital in a developing country possible? N Mambilima 1,2 , SM Rubow 1,2 1 University Teaching Hospital, Lusaka, Zambia; 2 Stellenbosch University, Stellenbosch, South Africa Correspondence: SM Rubow -University Teaching Hospital, Lusaka, Zambia EJNMMI Radiopharmacy and Chemistry 2016, 1(Suppl 1):PP41 Introduction: Pharmacopoeial or manufacturer's radiochemical purity (RCP) analysis methods are not always practical in a hospital setting, leading to modifications or substitution with quicker, simplified, or cost effective analytical procedures. This study aimed to determine whether appropriate validation procedures based on ICH Q2A and Q2B guidelines are feasible in a resource limited environment, such as most hospital radiopharmacy settings in Southern Africa. Materials and methods: Alternative RCP test methods for Tc-99m sestamibi involving the use of Whatman 31 ET (Wh) and Schleicher and Schuell (SS) chromatography paper were used. Locally procured Macherey-Nagel (MN) aluminium oxide TLC strips were intended as control method, as strips described in the manufacturer's instructions were unavailable. All analyses were performed on the 3 different strips in parallel, and in triplicate. In-house prepared Tc-99m sestamibi, colloid and pertechnetate were assumed to be 100% pure. Samples containing mixtures of varying concentrations of the radiochemical components were analysed. Results from tests performed by different operators were used to judge intermediate precision, and time delay between spotting and developing was used to evaluate robustness. Results: RCP of sestamibi without added impurities was 99.8%±0.0% MN, 99.5%±0.1% for Wh and 99.3%±0.2% for SS strips. Addition of pertechnetate and colloid to Tc-99m Sestamibi after completion of kit reconstitution, resulted in values for sestamibi higher than the calculated RCP for all 3 methods. The radiochromatogram scanner's limit of detection and limit of quantitation were determined. Discussion and conclusion: Due to the unexpected high RCP values after addition of impurities to sestamibi, all the analytical methods lacked specificity and accuracy. The MN test method showed exceptionally high values for sestamibi due to co-elution of the free pertechnetate with sestamibi. The MN RCP test method could therefore not be used as a reference standard. All three methods met the acceptance criteria for repeatability, intermediate precision, and robustness. Validating an analytical procedure in a hospital setting is only possible once some important prerequisites are met, such as availability of specified materials for the reference procedure, reliable reference standards, and availability of HPLC for radiopharmaceuticals that have impurities other than pertechnetate and colloid. A template validation protocol for TLC and paper chromatography was developed. . Nevertheless the purification of the crude product by means of semipreparative HPLC is unsatisfactorily time consuming (retention time t R ≈ 23 min). Therefore, the aim of this study was to establish a new set of conditions, which can reduce the retention time of the product and consequently reduce the total time of the synthesis. Methods: [ 18 F]FEPPA was synthesized as described elsewhere [3] with minor modifications in a Nuclear Interface synthesizer (GE Healthcare, Sweden). Briefly, the tosylate precursor dissolved in acetonitrile was added to the azeotropically dried [ 18 F]fluoride and the reactor was heated at 90°C for 10 minutes; after cooling, the reaction was quenched with a solution 50:50 acetate buffer:acetonitrile (pH=3,6) and automatically injected onto a semipreparative HPLC Column (Merck Chromolith® RP-18e, 100×10 mm). The product fraction was collected in water and the new aqueous solution was passed through a pre-conditioned C-18 plus SepPak cartridge. Finally, the product was eluted with ethanol and formulated with saline and phosphate buffer. Introduction: Indium-111 and gallium-68 labelled octreotide derivatives [1] are widely used in SPECT and PET imaging of somatostatin receptor expressing tumours and pancreatic dysfunction. In perspective of advantages of fluorine-18 (favourable half-life, high production capacity, low β-energy), more recently, derivatives based on Introduction and aims: Zein is the major storage protein of maize, with a "GRAS" status, that can be easily processed to form nanoparticles. Due to its amphiphilic character, mucoadhesive properties and a relatively high resistance to the effect of digestive enzymes, the resulting nanocarriers offer great potential for oral drug delivery purposes.The aim is optimization of 99m Tc radiolabelling of different kind of zein nanoparticles (ZNP) and the study by molecular imaging of their biodistribution in Wistar rats after oral gavage. The evaluated nanoparticles were bare zein nanoparticles (ZPN) and decorated with 3 different slippery polymers (ZNP-A, ZNP-B and ZNP-C). Materials and methods: All nanoparticles were prepared by a desolvation technique. For this purpose, zein were first dissolved in an ethanol:water solution, obtained by the addition of an aqueous solution and spray-dried. NP were pre-tinned with SnCl 2 and labelled with 99m TcO 4 -. Different SnCl 2 concentrations ranging from 0.005 to 1.0 mg/mL were used for radiolabelling optimization. RCP was analysed by radio-TLC. For biodistribution studies 4 MBq (0.33mg NP) of 99m Tc-nanoparticles were used per animal (n=12). SPECT/CT studies were performed 1,2,4,6 and 8h post-administration. SPECT acquisition protocol was set to account for radionuclide decay. For quantitative analysis data sets were exported to PMOD software and VOIs drawn over CT images on stomach and intestine, count ratios calculated in respect to total animal counts and maximum counts normalized to the last image (8h) for each nanoparticle type. Resuts: Radiochemical purity was >95% for ZNP-A and NPZ using [SnCl 2 ]=0.5 mg/mL, while 1.0 mg/mL was needed for ZNP-B and ZNP-C to get similar results. SPECT/CT images showed that unmodified NPZ had a biodistribution in stomach and intestine almost constant during the first 4 hours. 99m Tc-NPZ-B had a higher stomach mucoadhesion while 99m Tc-NPZ-A showed a similar behaviour but with faster gastric drainage and 99m Tc-NPZ-C quickly moved to intestine. All these results were confirmed by the ratios obtained from PMOD processed images. Conclusions: All Zein nanoparticles could be easily radiolabelled with 99mTc with >95% RCP. The results show a clear relationship between the biodistribution and the superficial properties which the coating material gives to the nanoparticle. Introduction: 68Ga-DOTANOC is an excellent radiopharmaceutical for imaging neuroendocrine tumours and gives superior quality images to equivalent peptides labelled with 111In. For that reason, we have been developing our 68Ga-DOTANOC radiolabelling service over the past 3 years. It is essential that we provide a high quality product and that the production is robust, reproducible and in line with GMP. Therefore, we have reviewed our quality data from the production of 68Ga-DOTANOC Materials and methods: 68Ga-DOTANOC has been prepared using an iTG 68Ge/68Ga generator and iQS fluidic labelling module. DOTA-NOC (ABX) 50-100 μg was dissolved in 0.25M sodium acetate and heated for 5 min at 110°C before elution of the generator in 4mL 0.05M HCl. The reaction was allowed to proceed for 10 min before purification over a Sep-Pak C8 Plus cartridge eluted with 50% ethanol and washed with 0.9% NaCl. The generator was flushed each day with 5ml 0.05M HCl when not used for radiolabelling and with 20ml 0.05M HCl on Monday mornings. The 68Ga-DOTANOC product was tested for free 68Ga and colloids by TLC and analysed by HPLC, pH was measured, endotoxin content assessed and radioactivity, volume and the presence of particles were checked prior to release of the product. 68Ge content and sterility were assessed retrospectively. Results: A total of 746 elutions were carried out between May 2013 and December 2015, the average elution yield was 85.5%. The average production yield (decay and generator yield corrected) was 66.5%. The average 68Ge breakthrough was 0.0028% for the 68Ga elution but 68Ge was not seen in the 68Ga-DOTANOC product. 296 production batches were made with 7 failures (2.4%) and these could all be put down to human error (leaks in the fluidic path, incorrect purification method etc.) and so have been minimised with training. No product has failed quality control tests for any reason. 499 patients have been imaged with the average number of patient's per production run being 1.7.

PP42
Discussion/conclusion: The preparation of 68Ga-DOTANOC is a very robust process giving a high quality product in a very reliable manner. In spite of high 68Ge content in the 68Ga elution with the iTG generator, the product has negligible 68Ge content. The product has very low levels of 68Ga colloids and negligible amounts of free 68Ga and gives a very clean HPLC trace. We conclude that this method of production gives a safe, high quality product.

PP46
In vivo biodistribution of adult human mesenchymal stem cells I (MSCS-ah) labeled with 99MTC-HMPAO administered via intravenous and intra-articular in animal model. Introduction: The application of adult human mesenchymal stem cells from bone marrow (MSCs-ah) is being considered a promising treatment of musculoeskeletal injuries, however, their trafficking and homing are still controversial issues with further studies needed. Our work is focused on in vivo biodistribution of 99mTc-HMPAO labelled MSCs-ah after both intravenous and intra-articular injection in an animal model. Materials and methods: 2 x 106 MSCs-ah isolated from bone marrow of healthy subjects using SEPAX system were suspended in 1 ml of PBS and labeled with up to 9.3 Bq/cel of 99mTc-HMPAO. Radiolabeled cell suspensions were administered to 8 adult male New Zealand rabbits (3.5-4 k) randomized in two groups. In group A (n=4), cell suspensions were administered via intravenous (marginal ear vein) and in group B (n=4) by intra-articular injection. After dynamic acquisition of images every 30 s for 25 min, whole body static images in anterior projection at 1,6 and 24 hours were acquired, previous sedation. No immunosuppressive agents were administered. Results: Early immune response to xenogenic MSCs-ah was not detected during the study. Neither adverse reaction nor technical complications were registered, so any and every animal was recruited for the study. In group A, high retention of the activity was observed in lung parenchyma, with kidney and bladder visualization from the start, and biliary and abdominal uptake from 1h, maintaining the pattern of distribution at 24h, with no significant activity in liver and spleen. Group B show activity in heart, spleen, liver, kidneys and bladder from the start to the late acquisition of 24h, with biliary and intestinal uptake from 6 h. No activity was observed in the lung parenchyma in this group. Discussion/conclusion: Exogenous MSCs-ah administered via intravenous are trapped mainly in lungs, with slight posterior retrafficking to other organs. On the other hand, no lung trapping is observed after intra-articular injection, pointing out the suitability of this route of administration for the therapeutic potencial of MSCs-ah in musculoskeletal pathology.

PP47
Synthesis of [ 18 F]F-exendin-4 with high specific activity Lehtiniemi P 1 , Yim C 2 , Mikkola K 1 , Nuutila P 1 , Solin O 1,2 performed at an injected dose of 1 MBq (0.02 nmol DOTA-peptide) at 30min, 4h, 24h, 48h, 72h and 168h p.i. (5 animals/group). Dose extrapolation to humans was based on linear scaling of injected activity per gram tissue between animals and humans and computed using OLINDA software. For experimental radionuclide therapy the animals were injected with both 177Lu-labelled DOTA-peptides at two different dose levels of 15 and 30 MBq corresponding to 0.6 and 1.2 nmol peptide (6 animals/group). For up to five weeks after treatment tumour volume and body weight was evaluated in comparison with a control group injected with physiological saline. Results and conclusion: Biodistribution studies in tumour-bearing mice revealed an uptake of >3.5% ID/g for both 177Lu-labelled DOTA-peptides in the A431-CCK2R-tumour 30min p.i.. This uptake remained stable for 4h p.i. and declined to >2% ID/g at 24h p.i.. A much lower uptake was observed in the A431-mock tumour. The tumour-to-kidney ratio resulted to be in the order of 3. In the experimental radionuclide therapy a clear therapeutic effect could be observed. In comparison to the control group the mean tumour volume doubling time of A431-CCK2R-tumours was increased by a factor of 1.8 and 2.6 in the 15 and 30 MBq group, respectively. For the A431-mock-tumours lower factors of 1.2 and 1.7 were observed in both treatment groups proving a receptorspecific effect. On the basis of dosimetric extrapolation to humans first therapeutic applications in patients should start with 4 repeated administrations of 3-5 GBq to limit the cumulative kidney dose to <27Gy. Based on patient individual dosimetry accompanying the first therapy the injected activity may be adapted accordingly.

PP49
Synthesis of radiopharmaceuticals for cell radiolabelling using anion exchange column Socan A 1 , Kolenc Peitl P 1 , Krošelj M 1 , Rangger C 2 , Decristoforo C 2 Introduction: 111In labelled radiopharmaceuticals are extensively used for cell labelling in routine clinical practice. Being members of coordinating radiometals group 68Ga and 89Zr are suitable candidates for synthesis of radiopharmaceuticals used for cell labelling. Due to its half life (78,4h) 89Zr labelled radiopharmaceuticals, could possibly enable long-term "in vivo" cell tracking with several attractive clinical applications (imaging of infection and inflammation, stem cell therapy). Aim of study was to develop a novel, versatile approach to prepare tracers (oxine, tropolone) using concentration on an anion exchange column. Materials and methods: The column (SepPAK QME) was washed with 2 ml of water. Samples of 68Ga, 111In, 89Zr-HEPES (0,5M, 1M) solutions, samples varying in pH (3-9) and volume were prepared and applied on column. Activity retained on, activity washed from column and pH of the solution were measured. Samples of 0.3 ml ligand solution (tropolone:1mg/ml, water; oxine:1mg/ml, 20%, 50% EtOH) were applied on the column and incubated. The column content was washed with 2 ml of PBS. Activity and pH measurements were performed as described above. Complex formations were analyzed using extraction method into octanol. Results: With 68Ga-HEPES (1M) yield of activity retained on the column was above 89% and was not pH (3.7-7.3) and volume dependent (0.5-2.5ml). Yield of 68Ga-oxine solution (20%EtOH) was between 43-77% with pH between 6.1-7.4 and extraction into octanol above 96%. Yield of activity retained on column with 111In-HEPES (1M) varied 31-98% and was pH and volume dependent. Yield decreased with volumes applied greater than 0.5 ml and pH bellow 4. Yield of 111In-tropolone solution was between 41 -61% with pH between 6-6.7 and extraction into octanol above 82%. Yield of 111In-oxine solution (20%EtOH) was between 41-96% and extraction into octanol above 92%. 89Zr-HEPES (0.5M) yield of activity retained on column was above 96% and was not pH (5.5-9) and volume dependent (0.3-1.5ml). Yield of 89Zr-tropolone solution was above 85% with pH between 7-7.5 and extraction into octanol above 94%. Yield of 89Zr-oxine solution (50%EtOH) was between 25-71% with pH between 7-9 and extraction into octanol above 86%. Conclusion: Concentration of coordinating radiometals 111In, 68Ga and 89Zr on an anion exchange column in HEPES allows on-column formation of tracers (oxine, tropolone) in very small volumes suitable for cell labelling with good yields and quality. This is a versatile and promising tool to prepare tracers on automated systems further used for cell labelling and potentially suitable for clinical practice.
Introduction: The development of dry kits containing the active ingredient and suitable excipients permits more efficient use of 68Ge/ 68Ga radionuclide generators, despite the limitations in the variety of generator eluent's composition and pH. Our aim was to develop a dry kit formulation for 68Ga radiolabeling of the PSMA inhibitor, PSMA-11 (Glu-CO-Lys(Ahx)-HBED-CC). Methods: A series of experiments on "wet" labelling in the presence of various amounts of sodium acetate and ascorbic acid were performed taking into consideration the challenge to find the composition of buffering agents ready to maintain pH value between 4 and 5 after addition of various volumes of 68Ga eluate (volumes of 1-4mL 0.1M HCl). For quality control of the 68Ga-PSMA-11 the RP-RadioHPLC (Kinetex C18 150mm; A: 0.1%TFA/H2O, B: 0.1%TFA/CAN) was used with gradient conditions (according to M. Eder et al. Pharmaceuticals 2014, 7, 779-796) as well as in isocratic elution (optimally set to 17% B) which visualized the radiolabelled and non-labelled PSMA-11 in UV chromatogram. The radiochemical purity also was tested by TLC (ITLC SG; 1: 0.9%NaCl/MeOH 80/20 v/v; 2: 0.9%NaCl/MeOH/ 25%NH3, 80/20/5 v/v/v; 3: 1M NH4OAc/MeOH 50/50 v/v). Results and discussion: Ascorbic acid (25mg/mL) added to the "wet" labelling mixture increased the radiolabeling yield (98.8%) compared to the labelling performed in acetate buffer only (95.0%). It also increased the buffering capacity of the formulation. These results were further used to formulate the dry kit composition using 30μg of PSMA-11, 60mg of sodium acetate and 12,5mg of ascorbic acid. The yield of 68Ga labelling of PSMA-11 from the freeze-dried kit was > 95%. The biodistribution of such prepared 68Ga-PSMA-11 was investigated in healthy Balb/c mice (n=5) after intravenous injection of 0.1mL (38 MBq/mL) (at 15, 30, 60 and 120min). 68Ga-PSMA-11 was rapidly cleared from the blood and excreted by kidney route with >70% urine elimination at 1h p.i. These results confirmed high stability of the 68Ga-PSMA-11 complex in vivo, with low contribution of free gallium-68, which circulates longer in blood stream. It is worth noting that the addition of ascorbic acid changes the biodistribution of free gallium and favors its blood clearance. This is probably due to the formation of week Ga complex with ascorbic acid which blocks Ga access to ferritin, hence resulting in lower liver and spleen accumulation. Introduction: The low energy electrons emitted in the Auger cascade of certain isotopes are expected to have a disproportionately high radiobiological effect. This is seen as the effect of the multiplicity and predominance of very low energy electrons in dose delivery. Despite many years of research in Auger emitters, only few direct measurements of the radiobiological effect of such Auger cascades have been published. One problem in making such fundamental dose-effect experiments is the method to bring Auger-emitting isotopes inside the cell and close to the nucleus in a predictable and quantifiable manner. Only when the location, activity, and time-activity profile are known it is possible to compare the observed damage with damage induced by the same dose and dose rate given by external irradiation. We have used the biological uptake of the Auger-emitting potassium analogue Cs-131 (9.7 d) into mammalian cells in culture as a test system for measuring the dose-effect of Auger electrons. Materials and methods: Cs-131 was repeatedly extracted from Ba-131 (11.5 d) made by high flux neutron irradiation at ILL (6 to 10 days at (1.1-1.3) 1015 n.cm-2s-1) of either natural Ba (17 mg as carbonate) or 49% enriched Ba-130 (0.15 mg as nitrate). Such targets were dissolved in hydrochloric acid, and re-precipitated with ammonium carbonate. The supernatant was spiked with sodium hydroxide, then dried and fired, leaving cesium-131 as a chloride salt with NaCl carrier. The re-precipitated targets were stored for 1-2 weeks for buildup of Cs-131, and then the process can be repeated. We have milked up to 4 batches of useful Cs-131 activity from a single activated barium batch from ILL. The harvested, 131Cs/NaCl salt was dissolved in water to reach isotonicity, and was offered to V-79 and HeLa cells in normal growth media. The cells invariantly up-concentrated the cesium activity, reaching a plateau after 8-10 hours. Results: Using enriched Ba-130, higher activity is obtained, but even with natural barium activities up to 80 MBq have been available repeatedly for the uptake experiments. Under optimal conditions, the cells in culture can reach intracellular activities over 1 Bq/cell during 4 hours incubation. The alkali-metal nature of cesium gives us reasons to assume a homogeneous intracellular distribution, allowing a first-principles calculation of the absorbed dose. With this method and unique isotope, we can compare the effect of equivalent absorbed doses of external gamma and internal, predominantly Auger delivered dose.  Introduction: Prostate cancer (PCa) is the most common cancer in men and the second most common cause in cancer-related deaths. 68Ga-RM2 is a nona-peptide with optimized binding sequence for Gastrin Releasing Peptide receptor (GRPr) which is overexpressed in PCa.1 In clinical studies 68Ga-RM2 has demonstrated its ability for detection of primary prostate cancer with high specificity due to its low uptake in normal prostate and in benign hyperplasia.2 Recent studies showed further potential of 68Ga-RM2 for detection of recurrent PCa and for imaging of estrogen receptor positive breast cancer.3,4. To provide 68Ga-RM2 for further clinical research, robust methods for preparation of this promising tracer are needed. Herein we describe the results of automated synthesizer based 68Garadiolabelings of RM2 as well as of simplified "shake-and-bake" kitpreparations. Materials and methods: The automated 68Ga-radiolabeling was optimized on a PharmTracer module (Eckert&Ziegler). The influence of several scavengers was investigated, as well as a processes with and without subsequent purification via C18 cartridge. Optimized conditions were used on further synthesizers (Scintomics, ITG). In a second approach, a simplified kit preparation was established. The 68Gagenerator eluate was added directly into a vial containing RM2precursor, buffer and scavenger. The vial was heated and optionally buffer was added for pH-adjustment. Results: Automated procedures on various synthesizers provided up to 850 MBq of 68Ga-RM2 in >70% uncorrected yield in 20 min including purification and formulation. The radiochemical purity was >97% (HPLC and TLC) if ascorbic acid was used as scavenger. The simple and easy to use kit preparation approach provided 68Ga-RM2 in 90% uncorrected yield and purity of >95%. Discussion/conclusion: 68Ga-RM2 can be reliably obtained on automated synthesizers as well as by a simple "shake-and-bake" kit preparation strategy. Both methods provided 68Ga-RM2 in high yields and high radiochemical purity.

PP55
Synthesis of pancreatic beta cell-specific [18F]fluoro-exendin-4 via strain-promoted aza-dibenzocyclooctyne/azide cycloaddition Cheng-Bin Yim 1,2 , Kirsi Mikkola 1,2 , Pirjo Nuutila 1,2 , Olof Solin 1,2 1 Turku PET Centre, University of Turku, Turku, Finland; 2 Åbo Akademi University, Turku, Finland Correspondence: Cheng-Bin Yim -Turku PET Centre, University of Turku and Åbo Akademi University, Turku, Finland EJNMMI Radiopharmacy and Chemistry 2016, 1(Suppl 1):PP55 Introduction: Diabetes has dictated many lives, and its lifetime treatment has accumulated into one of the most costly medical conditions, and yet, its pathophysicology is still undisclosed. However, efforts to develop sensitive noninvasive methods to quantify beta cell mass, which underlies the development of diabetes, have been challenged by the low abundance (1-2 %) and high dispersion of beta cells in the pancreas [1]. Recent preclinical studies using 18Flabelled exendin-4 showed specific targeting of pancreatic islets and insulinomas with favourable clearance kinetics that would potentiate clinical utility [2]. The focus of the present study is the radiosynthesis of a novel 18F-labelled exendin-4 analogue with a clear clinical prospective for imaging pancreatic beta cell mass. Materials and methods: The synthesis of [18F]fluoro-exendin-4 is depicted in Scheme 1. The dried [18F]fluoride-Kryptofix complex was reacted with tosylated prosthetic compound 1 in dimethylsulfoxide at 80°C. After chromatographic isolation, the 18F-labelled azide 2 was allowed to react with cyclooctyne-derivatised exendin-4 in ethanol/water at 60°C for 30 min. Isolation and radiochemical analysis of [18F]fluoro-exendin-4 was performed using high performance liquid chromatography (HPLC) with radiodetector. Results: Preliminary results showed efficient reaction between prosthetic reagent [18F]2 and exendin-4 precursor with a radiochemical yield of 30 %. The absence of major radioactive by-products assured neat purification using HPLC. The average isolated yield of [18F]exendin-4 after HPLC purification was 180 MBq starting from 3.5 GBq aqueous [18F]fluoride. Discussion: Currently, the scope of this reaction is being explored and its labelling conditions optimized. Preclinical studies with [18F]fluoroexendin-4 will include in vivo stability, in vivo distribution kinetics, and dosimetry calculations in healthy and diabetic animal models. Introduction: Automated modules for target processing and production of radiopharmaceuticals become to be a more and more required in both R&D and routine practice. However, it turns out that available systems for processing of targets for radiometal production and for labeling performed via microfluidic technology are still rather limited. Our aim was to develop a multipurpose automated systems for processing solid state targets and for operating microfluidic PMMA-based chip. Materials and methods: Stingray -Automated microfluidic system. The device is a versatile automated system that allows for control of variety of processes performed on a microfluidic chip. The system makes possible operations like precise mixing, separation, extraction or smallscale nanoparticle formation. It consists of 3 independent inlets for 3 different mobile phases with an in-built degasser, 4 peek solenoid valves, 2 independent nano piston pumps, 2 selectors (6/7), 2 manual inject valves with 100 μl loop volume (adjustable), 2/10 valve, 3 check valves and unique automated manifold for inserting microfluidic chip. This platform offers enough variability of reaction parameters and allows for a repeated return of a sample to the microfluidic chip. It may enhance the yield dramatically. CRABversatile platform for separation, formulation and simple labelling processes. The main parts of the system are two reactors, two selectors, peristaltic pump, 3/2 way valves, and the column. Prime reactor R1 allows for transport solid target material from shielding container to process position and for handling liquid target content. It is leakproof for 5 bars. There is an in-built solid phase extraction (SPE) column for separation processes driven by peristaltic pump and solvents. Four positions are available for uploading the solvents into the reactor R1 or on the SPE column. Splitting the separated radionuclide from the target matrix, including enriched material, is enabled thanks to the smart software checking the column output activity and controlling the splitting valves position. Final activity concentration can be precisely set via the case software without losses on the walls of reactor R2. There are 3 positions for uploading the solvents to the reactor R2 for formulation or for simple labelling steps like chelation. Results and conclusion: Both automated platforms are versatile, reliable tools that offer user-friendly settings for wide range of processes. Stingray is operable up to 200 bar back pressure allowing thus the flow rate of 20 ml/min. Crab was tested on separation of 61Cu and 64Cu from Ni targets in 99% separation yield of copper radionuclides and almost quantitative recovery of target matrix.