IMAGING OF RECURRENT INTESTINAL CARCINOMA WITH INDIUM-111-LABELED ANTICARCINOEMBRYONIC ANTIGEN MONOCLONAL-ANTIBODY CEA102

CEA102 is a mouse immunoglobulin G1 monoclonal antibody (mAb) that det ects 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 car cinoma patients. Evaluation included antibody pharmacokinetics and ass essment 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 s urgical inspection, pathological examination, and tissue radioactivity measurements. Tumor:serum ratios ranged from 0.20:1 to 3.22:1, and se rial biodistribution study of ''regions of interest'' also demonstrate d a high radioactivity in the tumor. These results indicated the poten tial exploitability of the 111-In-labeled mAb CEA102 in radioimmunodet ection of primary and extrahepatic recurrence of CEA-positive intestin al carcinomas.