CCKBR and neoplasm: Similarly, the tumor-to-kidney ratio increased from 2.22 ± 1.01 at 1 h to 4.16 ± 3.43 at 48 h despite its renal clearance, and the tumor-to-stomach ratio increased from 4.83 ± 1.46 at 1 h to 13.36 ± 6.42 at 96 h, suggesting minimal interference of physiologically expressed CCK2R. These results quantitatively support the high tumor specificity and prolonged retention of [177Lu]Lu-DOTA-CCK2R-dimer in vivo (Figure 3C, Table S5).