title: Clinical results and risk factors of proton and carbon ion therapy for hepatocellular carcinoma.
abstract: BACKGROUND
  The objective of this study was to evaluate the clinical outcome of proton and carbon ion therapy for hepatocellular carcinoma (HCC).
  
  
  METHODS
  In total, 343 consecutive patients with 386 tumors, including 242 patients (with 278 tumors) who received proton therapy and 101 patients (with 108 tumors) who received carbon ion therapy, were treated on 8 different protocols of proton therapy (52.8-84.0 gray equivalents [GyE] in 4-38 fractions) and on 4 different protocols of carbon ion therapy (52.8-76.0 GyE in 4-20 fractions).
  
  
  RESULTS
  The 5-year local control and overall survival rates for all patients were 90.8% and 38.2%, respectively. Regarding proton and carbon ion therapy, the 5-year local control rates were 90.2% and 93%, respectively, and the 5-year overall survival rates were 38% and 36.3%, respectively. These rates did not differ significantly between the 2 therapies. Univariate analysis identified tumor size as an independent risk factor for local recurrence in proton therapy, carbon ion therapy, and in all patients. Multivariate analysis identified tumor size as the only independent risk factor for local recurrence in proton therapy and in all patients. Child-Pugh classification was the only independent risk factor for overall survival in proton therapy, in carbon ion therapy, and in all patients according to both univariate and multivariate analyses. No patients died of treatment-related toxicities.
  
  
  CONCLUSIONS
  Proton and carbon ion therapies for HCC were comparable in terms of local control and overall survival rates. These therapies may represent innovative alternatives to conventional local therapies for HCC.
authors.affiliation: Department of Surgery, Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Komatsu
authors.forename: Takumi
authors.initials: T
authors.lastname: Fukumoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Demizu
authors.forename: Daisuke
authors.initials: D
authors.lastname: Miyawaki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Terashima
authors.forename: Ryohei
authors.initials: R
authors.lastname: Sasaki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hori
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hishikawa
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
authors.forename: Masao
authors.initials: M
authors.lastname: Murakami
mesh_terms: D000368:Aged; D002244:Carbon; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000628:therapy*; D005260:Female; D063193:Heavy Ion Radiotherapy; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000628:therapy*; D008297:Male; D061766:Proton Therapy; D012307:Risk Factors
chemical_list: D002244:Carbon