Two-fraction carbon ion radiotherapy for hepatocellular carcinoma

Abstract

15134 Background: In Japan, most patients with Hepatocellular Carcinoma (HCC) have liver cirrhosis, an advanced hepatic disorder, and they often require repeated therapies owing to the multicentric nature of carcinogenesis in the cirrhotic liver. Therefore, both radical effect and minimal invasiveness are essential for the treatment of HCC. However, there were no therapies satisfying both of these essential requirements for every-sized HCC. The purpose of this trial was to evaluate the safety and efficacy of two-fraction carbon ion radiotherapy (CIRT) for HCC. Methods: Eligibility criteria for this study were as follows: biopsy-proven HCC; recurrent or residual tumor after other ineffective treatments or no indication for any other treatment; no prior radiotherapy for target tumors; hepatic disorder of Child-Pugh grade A or B; Karnofsky performance status of 60–100; no other active cancer; and digestive tract not in contact with clinical target volume. CIRT was administered within dose escalation study of 32.0 to 38.8 cobalt gray equivalent (GyE) in 2 fractions for 2 days. Results: Between April 2004 and August 2006, 40 patients were totally enrolled. All patients had chronic liver diseases of Child-Pugh grade A in 37, B in 3. The median tumor size was 4.7 cm in diameter (2.0 to 6.7 cm). During a median follow-up of 32 months (range, 5–45 months), no hepatic failure resulting from the therapy and no treatment-related death occurred. Incidence of grade 3 early hepatic toxicity according to NCI-CTC ver.2 in the essential valuables concerning hepatic function was 0% in serum-GPT, ALB, prothrombin activity (PT%) and ALP, and 3% in T.BIL. No grade 4 toxicity has occurred. In 94% and 86% out of the patients, Child-Pugh score did not increase by more than 1 point in the early and late phases, respectively. In the lower-dose group (32.0, 33.6, 35.2 GyE: n=18), 2-year local control rate and overall survival rate were 71% and 83%, respectively. In the higher-dose group (37.0, 38.8 GyE: n=22), they were 100% and 90%, respectively. Conclusions: Although 2-fraction carbon ion radiotherapy seems to be safe and effective, and to have a promising potential as a new, radical, and minimally invasive therapeutic option for Hepatocellular Carcinoma, further careful follow-up is needed to confirm it’s clinical efficacy. No significant financial relationships to disclose.