Purpose: To evaluate the response to local radiotherapy (RT) for unresectable hepatocellular carcinoma (HCC) and to analyze the dose-response relationship and the treatment-related morbidities.
Methods and materials: Between 1998 and 2002, 59 patients who were treated with localized RT were evaluated. RT was delivered with a curative intent, and the radiation dose was 30-55 Gy (biologic effective dose of 39.0-70.2 Gy(10) using the alpha/beta ratio of 10 Gy) with 2-3 Gy as a daily dose. The tumor response was evaluated by the change in maximum tumor size on serial CT scans, and the morbidity was evaluated by the Common Terminology Criteria for Adverse Events v3.0.
Results: An objective tumor response was achieved in 39 of 59 patients (66.1%) with complete response (CR) in 5 patients and partial response (PR) in 34 patients. More than 50 Gy(10) had a significant response; CR or PR was 72.8% with >50 Gy(10) and 46.7% with < or =50 Gy(10) (p = 0.0299). The 2-year overall survival rate after RT was 27.4% (median survival time: 10 months), and this was affected by the tumor response (p = 0.0640); the 2-year overall survival rate after RT was 50.0% for CR and 21.8% for PR. There was no Grade 3 or 4 acute toxicity, and 3 patients (5.1%) developed gastric or duodenal ulcer.
Conclusions: Radiotherapy for unresectable HCC resulted in 66.1% of tumor response with acceptable toxicity, and the radiation dose seems to be a significant prognostic factor in RT response for HCC.