KDR and prostate cancer: PET imaging in a prostate cancer xenograft (PC3) mouse model demonstrated significant and sustained accumulation of 64Cu-DOTA-GU40C4 in VEGFR-2-positive PC3 tumors at 1, 4, and 20 h p.i. (2.25 ± 0.24, 2.15 ± 0.34, and 1.90 ± 0.18 %ID/g, respectively).