Carbon ion radiotherapy for 80 years or older patients with hepatocellular carcinoma.

BACKGROUND: To evaluate the safety and efficacy of carbon ion radiotherapy (C-ion RT) for 80 years or older patients with hepatocellular carcinoma (HCC).

METHODS: Eligibility criteria of this retrospective study were: 1) HCC confirmed by histology or typical hallmarks of HCC by imaging techniques of four-phase multidetector-row computed tomography or dynamic contrast-enhanced magnetic resonance imaging; 2) no intrahepatic metastasis or distant metastasis; 3) no findings suggesting direct infiltration of the gastrointestinal tract; 4) performance status ≤2 by Eastern Cooperative Oncology Group classification; and 5) Child-Pugh classification A or B. Patients received C-ion RT with 52.8 Gy (RBE) or 60.0 Gy (RBE) in four fractions for usual cases and 60.0 Gy (RBE) in 12 fractions for close-to-gastrointestinal tract cases. Toxicities were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events (Version 4.0).

RESULTS: Between March 2011 and November 2015, 31 patients were treated. The median follow-up period of all patients was 23.2 months (range: 8.4-55.3 months). Median age at the time of registration of C-ion RT was 83 years (range: 80-95 years). Child-Pugh grade A and B were 27 patients and 4 patients, respectively. The 2-year estimated overall survival, local control, and progression-free survival rates were 82.3%, 89.2%, and 51.3%, respectively. No patients had Grade 2 or higher acute toxicities (within 3 months after C-ion RT). One patient experienced progression in Child-Pugh classification from A to B within 3 months after C-ion RT. In late toxicities, Grade 3 encephalopathy was observed in 3 patients, and 2 improved with medication.

CONCLUSIONS: C-ion RT was effective with minimal toxicities for 80 years or older patients with hepatocellular carcinoma.

TRIAL REGISTRATION: UMIN000020571 : date of registration, 14 January 2016, retrospectively registered.