Radioimmunoguided surgery using iodine 125 B72.3 in patients with colorectal cancer
A. M. Cohen, E. W. Martin Jr, I. Lavery, J. Daly, A. Sardi, D. Aitken, K. Bland, C. Mojzisik and G. Hinkle
Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
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 x 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.
