March 1991

Radioimmunoguided Surgery Using Iodine 125 B72.3 in Patients With Colorectal Cancer

Author Affiliations

From the Memorial Sloan-Kettering Cancer Center, New York, NY (Dr Cohen); the Ohio State University College of Medicine, Columbus (Dr Martin, Ms Mojzisik, and Mr Hinkle); the Cleveland (Ohio) Clinic Foundation (Dr Lavery); the University of Pennsylvania School of Medicine, Philadelphia (Dr Daly); the Ochsner Clinic, New Orleans, La (Dr Sardi); Loma Linda (Calif) University Medical Center (Dr Aitken); and the University of Florida Medical Center, Gainesville (Dr Bland).

Arch Surg. 1991;126(3):349-352. doi:10.1001/archsurg.1991.01410270095015

• Preliminary data using B72.3 murine monoclonal antibody labeled with iodine 125 suggested that both clinically apparent as well as occult sites of colorectal cancer could be identified intraoperatively using a hand-held gamma detecting probe. We report the preliminary data of a multicenter trial of this approach in patients with primary or recurrent colorectal cancer. One hundred four patients with primary, suspected, or known recurrent colorectal cancer received an intravenous infusion of 1 mg of B72.3 monoclonal antibody radiolabeled with 7.4×10 Bq of iodine 125. Twenty-six patients with primary colorectal cancer and 72 patients with recurrent colorectal cancer were examined. Using the gamma detecting probe, 78% of the patients had localization of the antibody in their tumor; this included 75% of primary tumor sites and 63% of all recurrent tumor sites; 9.2% of all tumor sites identified represented occult sites detected only with the gamma detecting probe. The overall sensitivity was 77% and a predictive value of a positive detection was 78%. A total of 30 occult sites in 26 patients were identified. In patients with recurrent cancer, the antibody study provided unique data that precluded resection in 10 patients, and in another eight patients it extended the potentially curative procedure.

(Arch Surg. 1991;126:349-352)