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.

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.

Dosimetric comparison of carbon ion radiotherapy and stereotactic body radiotherapy with photon beams for the treatment of hepatocellular carcinoma.

BACKGROUND: The purpose of this study was to compare carbon ion radiotherapy (C-ion RT) and stereotactic radiotherapy (SBRT) with photon beams for the treatment of hepatocellular carcinoma (HCC), specifically with regard to the dose volume parameters for target coverage and normal tissue sparing. METHODS: Data of 10 patients who were treated using C-ion RT with a total dose of 60 Gy(RBE) in four fractions were used. The virtual plan of SBRT was simulated on the treatment planning computed tomography images of C-ion RT. Dose volume parameters such as minimum dose covering 90% of the planning target volume (PTV D90), homogeneity index (HI), conformity index (CI), mean liver dose (MLD), volume of the liver receiving 5 to 60 Gy (V5-60), and max point dose (Dmax) of gastrointestinal (GI) tract were calculated from both treatment plans. RESULTS: The PTV D90 was 59.6 ± 0.2 Gy(RBE) in C-ion RT, as compared to 56.6 ± 0.3 Gy in SBRT (p < 0.05). HI and CI were 1.19 ± 0.03 and 0.79 ± 0.06, respectively in C-ion RT, as compared to 1.21 ± 0.01 and 0.37 ± 0.02, respectively in SBRT. Only CI showed a significant difference between two modalities. Mean liver dose was 8.1 ± 1.4 Gy(RBE) in C-ion RT, as compared to 16.1 ± 2.5 Gy in SBRT (p < 0.05). V5 to V50 of liver were higher in SBRT than C-ion RT and significant differences were observed for V5, V10 and V20. Dmax of the GI tract was higher in SBRT than C-ion RT, but did not show a significantly difference. CONCLUSIONS: C-ion RT provides an advantage in both target conformity and normal liver sparing compared with SBRT.