Tumour imaging of bladder carcinomas and their metastases with 111indium-labelled monoclonal anti-CEA antibody BW 431/26.

Fifty-one patients with muscle-infiltrating bladder carcinoma (T2-T4, N0-3, M0-1) were studied with a new imaging technique using murine monoclonal antibody directed against the carcinoembryonic antigen (CEA). A total number of 67 investigations were performed. The intact 111indium-labelled antibody (BW 431/26, Behringwerke Marburg) detected 86% of primary tumours, 93% of local and 75% of distant metastases whether there was an elevated CEA level in serum or not. Immunohistologically (avidin-biotin-peroxidase method) positive frozen tissue sections from tumour biopsies stained with the same monoclonal anti-CEA antibody, thus confirming the presence of the CEA antigen in vitro. The method was of much higher sensitivity in detecting even very small metastases than X-ray computed tomography (86% versus less than 30%). The specificity was in the region of 90%. The response to chemotherapy (MVEC regimen) was shown by repeated studies demonstrating reduced uptake (partial remission) or no accumulation (complete remission) in the second immunoscan. We suggest immunoscintigraphy of bladder tumours and their metastases as an additional method in preoperative staging and postoperative care.