Whole‐body Autoradiography of Tumor‐bearing Hamsters with a New Tumor Imaging Agent, Indium‐111‐labeled Porphyrin

We have synthesized a new tumor imaging agent, (111)In‐labeled porphyrin ((111)In‐ATN‐2). In order to image transplantable pancreatic carcinoma in Syrian golden hamsters, we investigated the biodistribution of (111)In‐ATN‐2 72 hr after injecting the agent by means of whole‐body autoradiography. The efficacy of the agent was compared with that of (67)Ga citrate. The images with (111)In‐ATN‐2 were found to be clearer than those with (67)Ga citrate. Tumor‐to‐tissue radiodistribution ratios of the former were higher than those of the latter. Thus, (111)In‐ATN‐2 seems to be more useful for tumor diagnosis.