A gamma-detecting probe for radioimmune detection of CEA-producing tumors. Successful experimental use and clinical case report.

The detection of tumors with radiolabeled antibodies against CEA is possible; however, current nuclear medicine scanning cameras rarely detect tumors smaller than 2 cm in diameter. One of the limitations to tumor detection is the inability to place a detecting camera near a deeply seated intra-abdominal tumor. A hand-held gamma-detecting probe, suitable for intraoperative use, was designed to locate radioactive tumors. Experimental work with CEA-producing colon tumor xenografts in nude mice suggests this probe is more sensitive than external scanners in detecting small tumors. A case report documents the clinical use of this new intraoperative probe.