LESION-BY-LESION COMPARISON OF COMPUTERIZED-TOMOGRAPHY AND INDIUM-111-LABELED MONOCLONAL-ANTIBODY C110 RADIOIMMUNOSCINTIGRAPHY IN COLORECTAL-CARCINOMA - A MULTICENTER TRIAL

C110 is an anti-carcinoembryonic antigen murine IgG1 monoclonal antibo dy. Indium-111-labeled C110 radioimmunoscintigraphy (RIS) in colorecta l cancer was studied in 51 presurgical patients at four institutions. Planar and SPECT images were obtained at least twice between 48 and 96 hr after injection of 5 mCi/5 mg of In-111 C110. Fifty-one patients h ad 87 biopsy-proven lesions at surgery (57 hepatic, 30 extra-hepatic). Thirty-three patients (64.7%) had positive radionuclide scans, while 32 (62.8%) had positive CT scans (p = NS). While CT was better at over all lesion detection (62.1% versus 56%, p < 0.05), radionuclide scans were better than CT for extra-hepatic disease (60% versus 46.7%, p < 0 .01). Hepatic metastases (52.6%) were visualized by Mab scans to selec tively concentrate radioactivity. Uptake in draining lymph nodes was a significant limitation, making evaluation of these sites difficult. I ndium-111-C110 shows selective uptake in metastatic colorectal cancer, including more than half of all hepatic lesions evaluated.