Immunoscintigraphy in the follow-up of patients operated on for carcinoma of the sigmoid and rectum. Preliminary report with a new monoclonal antibody: B72.3.

Thirty patients who had curative surgery for sigmoid and rectal carcinoma were studied by immunoscintigraphy using a new monoclonal antibody: B72.3 radiolabeled with Iodine-131 (I-131) or Indium-111 (In-111). Results were compared with other conventional diagnostic procedures such as computed tomography, ultrasound, endoscopy, and tumor markers. Seven patients had local recurrences and/or distant metastases. Immunoscintigraphy identified all local recurrences (five cases) that were confirmed by CT and was able to localize three of five liver metastases (two false-negatives). Furthermore, immunoscintigraphy also recorded a false-positive. Preliminary use of B72.3 shows good potential for the evaluation and detection of neoplastic sites.