title: A phase II study of hypofractionated proton therapy for prostate cancer.
abstract: BACKGROUND
  Hypofractionated radiotherapy potentially offers therapeutic gain for prostate cancer. We investigated the feasibility of hypofractionated proton therapy (PT).
  
  
  METHODS
  Eighty-two patients with biopsy-proven T1-3N0M0 prostate adenocarcinoma and no history of androgen deprivation therapy were randomly assigned to five different dose schedules: Arm 1, 60 CGE (cobalt gray equivalent = proton dose in Gy × 1.1)/20 fractions/5 weeks; Arm 2, 54 CGE/15 fractions/5 weeks; Arm 3, 47 CGE/10 fractions/5 weeks; Arm 4, 35 CGE/5 fractions/2.5 weeks; or Arm 5, 35 CGE/5 fractions/5 weeks.
  
  
  RESULTS
  The median follow-up duration was 42 months (11-52 months). The acute GI and GU grade ≥ 2 toxicity rates were 0 and 5%, respectively. The late GI and GU grade ≥ 2 toxicity rates were 16% and 7%, respectively. The best arm for acute GU toxicity was Arm 3, while that for late GI toxicity was Arm 2 in which none had grade ≥ 2 toxicity. The four-year American Society for Therapeutic Radiology and Oncology and Nadir + 2ng/ml BCF free survival (BCFFS) rates were 85% and 86%, respectively.
  
  
  CONCLUSIONS
  Hypofractionated PT for patients with prostate adenocarcinoma as used in this study is feasible with an acceptable toxicity profile. As the BCFFS rates do not seem to be inferior to those produced using conventional fractionation, the application of hypofractionated PT may save patients time and money.
authors: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors: Yeon-Joo
authors: YJ
authors: Kim
authors: Kwan Ho
authors: KH
authors: Cho
authors: Hong Ryull
authors: HR
authors: Pyo
authors: Kang Hyun
authors: KH
authors: Lee
authors: Sung Ho
authors: SH
authors: Moon
authors: Tae Hyun
authors: TH
authors: Kim
authors: Kyung Hwan
authors: KH
authors: Shin
authors: Joo-Young
authors: JY
authors: Kim
authors: Se Byeong
authors: SB
authors: Lee
authors: Byong Ho
authors: BH
authors: Nam
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D041981:Gastrointestinal Tract / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods*; D011832:Radiation Injuries / Q000453:epidemiology; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012007:Rectum / Q000473:pathology; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000473:pathology