High detectability of metastatic colorectal carcinoma with In-111 ZCE 025 monoclonal antibody

Twelve patients with colorectal carcinoma were studied with In-111-labeled monoclonal antibodies (MoAb) to carcinoembryonic antigen, type ZCE 025. Patients received 5.0 mCi of In-111 ZCE 025 at doses of 2.5-20.0 mgMoAb and were imaged 3 and 6 days after infusion. In-111 MoAb imaging detected 19 of 23 tumor sites (82% detection rate); confirmed at surgery, autopsy, and on diagnostic radiography. With respect to tumor sites, MoAb imaging detected 12 of 12 lymph node metastases, three of four lung metastases, two of two local recurrences, and two of five primary tumors. The high detectability of metastases from colorectal carcinoma with In-111-labeled ZCE 025 demonstrates the potential use of this antibody as a diagnostic and therapeutic agent