A feasibility study of high-dose hypofractionated carbon ion radiation therapy using four fractions for localized hepatocellular carcinoma measuring 3 cm or larger.

Abstract

To evaluate the safety of carbon-ion radiotherapy (C-ion RT) using 60 Gy (relative biological effectiveness, RBE) in four fractions for patients with hepatocellular carcinoma (HCC). The primary outcome was acute toxicities within 90 days. The secondary outcomes were late toxicities, local control, and progression-free survival and overall survival rates. The key inclusion criteria were as follows: (1) 3 cm or larger HCC without major vascular invasion and not adjacent to the alimentary tract; (2) Child-Pugh's grade A/B; and (3) without extrahepatic metastasis. A total of 21 cases were analyzed between October 2012 and April 2016. The median follow-up period among the 17 survivors was 24.2 (range: 6.3-43.7) months. Grade 3 or higher acute toxicity was not observed, while three (14.3%) of the 21 patients experienced grade 3 late toxicities. The 1- and 2-year local control, progression-free survival, and overall survival rates were 100% and 92.3%, 81.0% and 50.0%, and 90.5% and 80.0%, respectively. C-ion RT using 60 Gy (RBE) in four fractions was safe and achieved promising local tumor control.