Four-fraction carbon ion radiotherapy for hepatocellular carcinoma: results of a phase II clinical trial

Abstract

4090 Background: Both radicality and minimal invasiveness are essential for the treatment of hepatocellular carcinoma (HCC), because in 85% of all patients the condition is associated with liver cirrhosis. Carbon ion radiotherapy is expected to potentially have both the natures because of its excellent dose distribution and its high cytocidal effect resulting from biologically unique characteristics. Methods: Forty-four patients with histologically documented HCC were treated with 4-fraction carbon ion radiotherapy of 52.8 GyE total dose from April 2001 to February 2003. In this report, thirty-six patients with 36 lesions, whose follow-up periods were longer than one year, were the subjects. Fifteen had recurrent tumors (locally: 9, regionally: 6). Six were at Stage I of the disease, 20 at Stage II and 10 at Stage IIIA according to the UICC criteria (Sixth Edition). Child-Pugh grade was A in 28 and B in 8 patients. Mean maximum tumor size was 4.0 (1.2–7.5) cm in diameter. Anti-tumor effect was evaluated by the best tumor response based on the WHO criteria, cumulative local control rate and overall survival rate calculated by Kaplan-Meier method. NCI-Common Toxicity Criteria (CTC) modified by the Liver Cancer Working Group and RTOG/EORTC criteria were used for evaluation of toxicity. Results: During a median follow-up of 23 (15–31) months, no severe adverse effects and no treatment-related deaths have occurred. As to the best tumor response, the ratio of the number of CR and PR to that of all the lesions was 28/36 (78%). Local control rates were 97% and 89% at 1 and 2 year, respectively. Overall survival rates were 92% and 85% at 1 and 2 year, respectively. Within 3 months after the start of therapy, Grade 3 hepatic reaction according to the modified CTC was observed in 3% out of the subjects. Within 3 to 12 months after the start of therapy, no Grade 3 or more hepatic reaction was observed. None of the subjects died of hepatic failure within 1 year after the start of therapy. Conclusions: Four-fraction carbon ion radiotherapy using 52.8 GyE total dose preliminarily proved to be safe and effective for patients with HCC associated with chronic liver disease. No significant financial relationships to disclose.