Imaging of Recurrent Intestinal Carcinoma with Indium‐lll‐labeled Anti‐carcinoembryonic Antigen Monoclonal Antibody CEA102

CEA102 is a mouse immunoglobulin Gl monoclonal antibody (mAb) that detects an epitope of carcinoembryonic antigen (CEA). The biodistribution and imaging characteristics of indium‐111‐labeled (111‐In)‐mAb CEA102 were studied in 1 primary and 9 extrahepatic recurrent intestinal carcinoma patients. Evaluation included antibody pharmacokineties and assessment of antibody distribution in surgical specimens, in comparison with whole body imaging using a gamma camera, and imaging with single photon emission computed tomography. Selective mAb CEA102 localization to tumor tissue was demonstrated in 7 patients with tumors over 2 cm in size, and the external images correlated well with the results of surgical inspection, pathological examination, and tissue radioactivity measurements. Tumor: serum ratios ranged from 0.20:1 to 3.22:1, and serial biodistribution study of “regions of interest” also demonstrated a high radioactivity in the tumor. These results indicated the potential exploitability of the 111‐In‐labeled mAb CEA102 in radioimmunodetection of primary and extrahepatic recurrence of CEA‐positive intestinal carcinomas.