Comparative tumor dose from 131I-labeled polyclonal anti-ferritin, anti-AFP, and anti-CEA in primary liver cancers.

Results of dosimetric studies are reported for 30 patients with hepatoma and 5 patients with primary hepatic cholangiocarcinoma who received treatment with 131I-labeled polyclonal antibodies. Studies included liver and tumor volume computations from X-ray CT scans, in vivo quantitation of the activity of radiolabeled antibodies in hepatic tumors and normal liver tissue, and effective half-life measurements. Twenty-two patients with hepatoma were administered 131I-labeled polyclonal anti-ferritin. Five hepatoma patients, who were AFP-positive, were administered anti-alpha-fetoprotein (AFP). Three patients with AFP-positive hepatomas received both 131I-labeled anti-ferritin and anti-AFP in a bolus. The five cholangiocarcinoma patients were treated with 131I-labeled anti-carcinoembryonic antigen (CEA). For administered activities of 30 mCi on day 0 and 20 mCi on day 5, mean values of the radiation dose to hepatomas were approximately 1100 rads for anti-ferritin, 350 rads for anti-AFP, and 960 rads for the combination of anti-ferritin and anti-AFP. Polyclonal anti-ferritin has, therefore, become the antibody of choice in the treatment of hepatoma. The radiation dose to cholangiocarcinomas from 131I-labeled anti-CEA and administered activities of 20 mCi on day 0 and 10 mCi on day 5 was approximately 620 rads. Total-body irradiation for these injection schedules ranged from 30 to 50 rads.