CCKBR and neoplasm: In vivo, [nat/177Lu]Lu-DOTA-rhCCK-18 revealed a 1.5 and 13-fold increased activity uptake in the tumor (25.4 ± 4.7 %ID/g, Figure 4) at 24 h p.i., as compared to the previously published compound, [177Lu]Lu-(R)-DOTAGA-rhCCK-16 (15.7 ± 3.3 %ID/g), and the parent peptide, [177Lu]Lu-DOTA-PP-F11N (1.9 ± 0.8 %ID/g), respectively, which can be attributed to its significantly higher CCK-2R affinity and internalization [19].