title: Clinical results of proton beam therapy for hepatocellular carcinoma over 5 cm.
abstract: OBJECTIVE
  This study aimed to evaluate the safety and efficacy of proton beam therapy for large hepatocellular carcinoma (HCC).
  
  
  METHODS
  Twenty-four patients with a HCC larger than 5.0 cm were treated with proton beam therapy at our institution between 2008 and 2015.
  
  
  RESULTS
  The clinical stage was I in 2 patients, II in 9 patients, and IIIB in 13 patients. Ten of the 24 patients were not surgical candidates because of advanced HCC or old age. Median tumor size was 90 mm (range, 50-180 mm). Median total dose delivered was 72.6 Gray-equivalents (GyE) in 22 fractions (range, 60.8-85.8 GyE). Median follow-up period was 17.5 months (range, 3-70 months). Local control rate at 2 years was 87.0%. The 2-year overall survival rate was 52.4%. The predominant tumor progression pattern was new hepatic tumor development outside the irradiated field. No acute or late treatment-related toxicity of grade 3 or higher, other than dermatitis, was observed.
  
  
  CONCLUSIONS
  These results show that proton beam therapy offers an effective and safe method for treating patients with large HCC. Proton beam therapy represents a promising method for treatment of large-volume HCC.
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ono
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Azami
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Motohisa
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Endo
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Teruhito
authors.initials: T
authors.lastname: Takeyama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku BNCT Research Center, Koriyama, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hirose
authors.affiliation: Department of Radiation Oncology, Southern Tohoku BNCT Research Center, Koriyama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kikuchi
keywords: clinical medicine; findings; hepatocellular carcinoma; proton beam therapy