Results of the First Prospective Study of Carbon Ion Radiotherapy for Hepatocellular Carcinoma with Liver Cirrhosis

Purpose: To evaluate the toxicity and antitumor effect of carbon ion radiotherapy for hepatocellular carcinoma within a Phase I-II trial.

Methods And Materials: Between June 1995 and February 1997, 24 patients with histopathologically proven hepatocellular carcinoma were treated to 15 fractions within 5 weeks in a step-wise dose-escalation study. The disease stage was Stage II in 10, IIIA in 6, and IVA in 8 patients. The Common Toxicity Criteria, Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer criteria, and Child-Pugh score were used to evaluate toxicity. The antitumor effect was evaluated by the tumor response, cumulative local control, and survival rates.

Results: During a median follow-up of 71 months (range, 63-83 months), no severe adverse effects and no treatment-related deaths occurred. The Child-Pugh score did not increase by >2 points after the start of therapy. In 78% and 75% of all patients, the score did not increase by >1 point in the early and late phase, respectively. The overall tumor response rate was 71%. The local control and overall survival rate was 92% and 92%, 81% and 50%, and 81% and 25% at 1, 3, and 5 years, respectively.

Conclusion: Carbon ion radiotherapy appears safe and effective for patients with hepatocellular carcinoma. Additional clinical studies using a larger subject group are required to confirm the therapeutic efficacy.