PURPOSE: To evaluate the efficacy of combined therapy involving intra-arterial hepatic chemoinfusion through a percutaneously implanted port and external irradiation for the treatment of advanced hepatocellular carcinoma. MATERIALS AND METHODS: Fifteen patients (12 males and 3 females; mean age=47.5 years) with advanced hepatocellular carcinoma localized in one lobe and with portal vein thrombosis (stage IVa) were included in this study. To permit chemoinfusion through the hepatic artery, a Chemoport(R); was implanted percutaneously in the right inguinal area via the femoral artery. Initial external radiation therapy lasted five weeks (44 Gy in a daily fraction of 1.8 Gy), with concurrent intra-arterial hepatic infusion of 5-fluorouracil. This initial treatment was followed by five cycles of intra-arterial hepatic infusion of cisplatin and 5-fluorouracil for three consecutive days every month. Two and six months after treatment was begun, the patients underwent CT scanning and angiography, and their response was assessed in terms of change in tumor size and vascularity, the degree of portal vein thrombosis and arterio-portal shunt, and alpha-fetoprotein levels. Any complications arising from this combined therapy and the clinical status of each patient were also followed up during the treatment period. RESULTS: The response rates at months 2 and 6 were 60% and 33.3%, respectively. One patient (6.7%) showed complete remission, and serum alpha-fetoprotein levels decreased significantly in all patients who responded. In five of the twelve patients, the thrombi in the main portal vein showed marked regression. The one-year survival rate was 30% and the median survival period was 10.6 (range, 3.7 to 28) months. The complications arising after treatment involved the catheter-port system (n=2) or were due to gastroduodenitis (n=9). CONCLUSION: In these patients with advanced hepatocellular carcinoma and portal vein thronbosis, combined therapy involving hepatic arterial chemoinfusion through a Chemoport(R) and external irradiation achieved favorable results. Further controlled studies aimed at evaluating the prognostic factors involved are, however, required.