The value of immunoscintigraphy in the detection of recurrent colorectal cancer.

The aim of this prospective study was to determine whether anti-carcinoembryonic antigen (anti-CEA) scintigraphy is a useful additional technique in the diagnosis recurrence of colorectal cancer. Forty patients with suspected recurrence of colorectal cancer, underwent immunoscintigraphy (IS) and helical computed tomography (CT) in the 2 weeks before surgery. Surgical findings were used to evaluate the performance of the imaging techniques. Suspected areas on IS and CT were systematically explored. Helical CT was found to be superior to IS for the liver, the sensitivity and specificity of CT being 100% and 90%, respectively, vs 53% and 100% for IS. However, IS was better than CT for the detection of extra-hepatic abdominal recurrence: sensitivity and specificity of IS were 100 and 82% respectively vs 33 and 82% for CT. Seven cases of peritoneal carcinomatosis were overlooked by helical CT. Our results indicate that IS improves detection of extra-hepatic abdominal recurrence of colorectal cancer. Immunoscintigraphy is valuable as a guide to the treatment strategy and operative procedures.