Radioimmunotherapy for unresectable hepatocellular carcinoma using 131I-Hepama-1 mAb: preliminary results.

Twenty-three patients with surgically verified unresectable hepatocellular carcinoma (HCC) have been treated by intrahepatic arterial administration of 131I-labeled anti-HCC monoclonal antibody (Hepama-1) combined with hepatic artery ligation. Radioimmunoimaging demonstrated that the median tumor/liver ratio was 2.1 (1.1-3.6) at day 5. A decline in alpha-fetoprotein level and shrinkage of tumor were observed in 75% (12/16) and 78% (18/23) of patients respectively. Sequential resection was done in 11 patients (48%) after treatment. The surgical specimens revealed massive necrosis of tumor, but residual cancer cells were found at the edge of the specimens. Anti-antibody was determined in 43% (10/23) of patients 2-4 weeks after the administration of 131I-Hepama-1 mAb. No marked toxic effects were noted. It is suggested that 131I-Hepama-1 mAb might be of value as one of the multimodality treatments for unresectable HCC.