title: Dosimetry and preliminary acute toxicity in the first 100 men treated for prostate cancer on a randomized hypofractionation dose escalation trial.
abstract: OBJECTIVE
  The alpha/beta ratio for prostate cancer is postulated to be between 1 and 3, giving rise to the hypothesis that there may be a therapeutic advantage to hypofractionation. The dosimetry and acute toxicity are described in the first 100 men enrolled in a randomized trial.
  
  
  METHODS
  The trial compares 76 Gy in 38 fractions (Arm I) to 70.2 Gy in 26 fractions (Arm II) using intensity modulated radiotherapy. The planning target volume (PTV) margins in Arms I and II were 5 mm and 3 mm posteriorly and 8 mm and 7 mm in all other dimensions. The PTV D95% was at least the prescription dose.
  
  
  RESULTS
  The mean PTV doses for Arms I and II were 81.1 and 73.8 Gy. There were no differences in overall maximum acute gastrointestinal (GI) or genitourinary (GU) toxicity acutely. However, there was a slight but significant increase in Arm II GI toxicity during Weeks 2, 3, and 4. In multivariate analyses, only the combined rectal DVH parameter of V65 Gy/V50 Gy was significant for GI toxicity and the bladder volume for GU toxicity.
  
  
  CONCLUSIONS
  Hypofractionation at 2.7 Gy per fraction to 70.2 Gy was well tolerated acutely using the planning conditions described.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA. Alan.Pollack@FCCC.edu
authors.forename: Alan
authors.initials: A
authors.lastname: Pollack
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hanlon
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Feigenberg
authors.forename: Andre A
authors.initials: AA
authors.lastname: Konski
authors.forename: Benjamin
authors.initials: B
authors.lastname: Movsas
authors.forename: Richard E
authors.initials: RE
authors.lastname: Greenberg
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
authors.forename: C-M Charlie
authors.initials: CM
authors.lastname: Ma
authors.forename: Shawn W
authors.initials: SW
authors.lastname: McNeeley
authors.forename: Mark K
authors.initials: MK
authors.lastname: Buyyounouski
authors.forename: Robert A
authors.initials: RA
authors.lastname: Price
mesh_terms: D019583:Dose Fractionation, Radiation; D041981:Gastrointestinal Tract / Q000528:radiation effects; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012007:Rectum / Q000528:radiation effects; D012306:Risk; D047368:Tumor Burden; D001743:Urinary Bladder / Q000528:radiation effects