RESUMO
<p><b>OBJECTIVE</b>To evaluate the feasibility and efficacy of radioimmunotherapy with 131 I-labeled humanized anti-HBsAg Fab (131 I-anti-HBsAg Fab) combined with 131 I-labeled anti-nucleus antigen monoclonal antibody chTNT (131 I-chTNT) in nude mice bearing human hepatocellular carcinoma.</p><p><b>METHODS</b>Nude mice bearing subcutaneous human hepatocellular carcinoma xenografts were treated by intratumoral injection of 131 I-anti-HBsAg Fab and/or 131 I-chTNT, and the changes in the tumor size and alterations in the radioactivity concentration in the tumor and non-tumor tissues were observed.</p><p><b>RESULTS</b>The tumor inhibition rate in mice treated with 131 I-anti-HBsAg Fab combined with 131 I-chTNT (73.09%) was significantly higher than that in mice treated with 131 I-anti-HBsAg Fab (47.8%) or 131 I-chTNT (54.26%) alone. Combined treatment also resulted in significantly higher tumor-to-normal radioactivity concentration ratios than the treatment with the single agents.</p><p><b>CONCLUSION</b>Intratumoral injection with 131 I-labeled monoclonal antibodies can increase the radioactivity concentration in the tumor and enhance the efficacy of the radioimmunotherapy in nude mice bearing human hepatocellular carcinoma.</p>