PURPOSE: Recent reports have shown that a portion of the liver can tolerate higher radiation doses, which can be further accomplished by the application of 3-dimensional conformal radiotherapy (3-DCRT). The purpose of this study was to investigate the efficacy and toxicity of 3-DCRT combined with transcatheter arterial chemoembolization (TACE) for HCC in the cirrhotic patients. METHODS AND MATERIALS: From 1994 to 2000, 50 HCC patients with liver cirrhosis (LC) were included in this study. The degree of LC was Child A in 38 and Child B in 12. The UICC stages were II in 12, III in 16, and IVa in 22. The mean tumor size was 8.3+/-3.5 cm. Patients were treated with TACE and then followed by 3-DCRT within 7-14 days. 3-DCRT planning was used to define both the target and normal liver volumes. The total dose of radiation (mean 50.1+/-8.3 Gy) was determined by the fractional volume of normal liver receiving 50% of the isocenter dose. RESULTS: A partial response (PR) was observed in 33 patients (66%). A subsequent surgical resection was successful in three patients, showing complete necrosis in one and near total necrosis in two. Most common acute toxicity was alteration in liver function test (13 patients) and none of the patients showed an acute toxicity more than grade 3. Subacute and chronic toxicity involved radiation induced liver disease (RILD) (six patients) and gastrointestinal toxicity (seven patients; ulcer in five and hemorrhagic mucositis in two). The actuarial survival rate at 3 years was 43% from the commencement of radiotherapy. CONCLUSIONS: Radiotherapy using 3-DCRT combined with TACE can achieve a substantial tumor response and survival rate for HCC in the cirrhotic patients.