Immunoscintigraphy of colorectal carcinoma with monoclonal antibody 791T/36

A monoclonal antibody 791T/36 prepared against a human osteogenic sarcoma has been used to detect primary and metastatic colorectal carcinoma by external imaging of patients infused with 131I-labelled antibody. Positive images were obtained with 8/11 primary colon tumours, 5/12 rectal tumours and 14/15 secondary and recurrent tumours. Positive tumour localization of radiolabelled antibody was confirmed by imaging and radioactivity counts on resected specimens. None of five patients with benign colorectal disease showed positive images and only 2/12 other gastrointestinal cancers were detected.