Initial Results of Hypofractionated Carbon Ion Radiotherapy for Cholangiocarcinoma.

AIM To report initial results of hypofractionated carbon ion radiotherapy (C-ion RT) for cholangiocarcinoma. PATIENTS AND METHODS Data regarding seven patients with cholangiocarcinoma treated by C-ion RT were analyzed. Prescribed doses were 52.8 Gy [relative biological effectiveness (RBE)] or 60.0 Gy (RBE) in four fractions for intrahepatic cases and 12 fractions for hilar hepatic/close to gastro-intestinal tract cases. Local control and overall survival were evaluated and toxicity was graded using Common Terminology Criteria for Adverse Events, version 4.0. RESULTS The median follow-up period was 16 months. There were two patients with stage I cancer, one with stage II, one with stage III, and three with stage IVA. Local control was achieved in five out of seven patients (71%) and survival was maintained in six out of seven patients (86%). There were no occurrences of acute or late toxicity of grade 3 or higher. CONCLUSION Initial results show that hypofractionated C-ion RT appears to be tolerated and effective for cholangiocarcinoma.