Fig. 2

Experimental design for systemic study (SYS group) and intraglandular blocking study (CAN group) for the dose-finding in non-tumor-bearing cohort (a, b). The tissue/blood ratios of [¹⁸F]DCFPyL in submandibular salivary glands (SMG) and kidney at 1 h post-injection are shown for the SYS group (panels c, d) and for the CAN group (panels e, f), respectively. Mice were injected either with 50 µl of saline control or with DCFPyL at 1× to 1000× molar equivalent of the systemically injected [¹⁸F]DCFPyL dose. Each value in the graphs represents mean tissue/blood ratios ± SD, n = 5–6 for each group, with statistically significant results (P < 0.05) indicated by asterisk. The CAN 1 × group shows the expected local blocking at the SMG and lack of blocking at the kidneys (tumor surrogate). However, unexpected blocking of the kidneys is seen in the CAN group at the 10–1000× level, perhaps due to “leakage” of DCFPyL from intraglandular administration into the systemic circulation