Fig. 4

Biodistribution of [¹⁸F]FPyPEGCBT-c(RGDfK) in nude mice bearing U-87 MG or SKOV-3 subcutaneous tumours. Mice intravenously injected with 3–5 MBq [¹⁸F]FPyPEGCBT-c(RGDfK) were sacrificed and indicated organs were collected after uptake times of 30, 60 or 120 min (a). For the blocking experiments, mice were injected intravenously with 20 mg/kg of c(RGDfV) 5 min prior to [¹⁸F]FPyPEGCBT-c(RGDfK) injection and indicated organs were collected after 60 min of uptake (b). [¹⁸F]FPyPEGCBT-c(RGDfK) uptake in the indicated organs was quantified in a γ-counter and expressed as percentages of the injected dose per gram (%ID/g) (a, b). Tumours-to-blood and Tumours-to-muscle %ID/g ratios were also determined for the uptake time course of [¹⁸F]FPyPEGCBT-c(RGDfK) (c) and the blocked experiment (d). Data are means ± SD (n ≥ 7) and statistical differences were analysed with the one-way ANOVA test followed by Dunnett’s post hoc test as compared with 0.5 h uptake time (c) or with non-blocked 1 h uptake time (d); *p < 0.05, **p < 0.01, #p < 0.001