title: Acute toxicity of hypofractionated intensity-modulated radiotherapy for prostate cancer.
abstract: BACKGROUND
  Dose-escalated hypofractionated radiotherapy (hfrt) using intensity-modulated radiotherapy (imrt), with inclusion of the pelvic lymph nodes (plns), plus androgen suppression therapy (ast) in high-risk prostate cancer patients should improve patient outcomes, but acute toxicity could limit its feasibility.
  
  
  METHODS
  Our single-centre phase ii prospective study enrolled 40 high-risk prostate cancer patients. All patients received hfrt using imrt with daily mega-voltage computed tomography imaging guidance, with 95% of planning target volumes (ptv68 and ptv50) receiving 68 Gy and 50 Gy (respectively) in 25 daily fractions. The boost volume was targeted to the involved plns and the prostate (minus the urethra plus 3 mm and minus 3 mm from adjacent rectal wall) and totalled up to 75 Gy in 25 fractions. Acute toxicity scores were recorded weekly during and 3 months after radiotherapy (rt) administration.
  
  
  RESULTS
  For the 37 patients who completed rt and the 3-month follow-up, median age was 65.5 years (range: 50-76 years). Disease was organ-confined (T1c-T2c) in 23 patients (62.1%), and node-positive in 5 patients (13.5%). All patients received long-term ast. Maximum acute genitourinary (gu) and gastrointestinal (gi) toxicity peaked at grade 2 in 6 of 36 evaluated patients (16.6%) and in 4 of 31 evaluated patients (12.9%) respectively. Diarrhea and urinary frequency were the chief complaints. Dose-volume parameters demonstrated no correlation with toxicity. The ptv treatment objectives were met in 36 of the 37 patients.
  
  
  CONCLUSIONS
  This hfrt dose-escalation trial in high-risk prostate cancer has demonstrated the feasibility of administering 75 Gy in 25 fractions with minimal acute gi and gu toxicities. Further follow-up will report late toxicities and outcomes.
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB. ; Currently: Department of Radiation Oncology, Eastern Health, Dr. H. Bliss Murphy Cancer Centre, St. John's, NL.
authors.forename: C S
authors.initials: CS
authors.lastname: Drodge
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: O
authors.initials: O
authors.lastname: Boychak
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: S
authors.initials: S
authors.lastname: Patel
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: N
authors.initials: N
authors.lastname: Usmani
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: J
authors.initials: J
authors.lastname: Amanie
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: M B
authors.initials: MB
authors.lastname: Parliament
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: A
authors.initials: A
authors.lastname: Murtha
authors.affiliation: Division of Medical Physics, Cross Cancer Institute, Edmonton, AB.
authors.forename: C
authors.initials: C
authors.lastname: Field
authors.affiliation: Division of Medical Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: S
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
authors.forename: N
authors.initials: N
authors.lastname: Pervez
keywords: Hypofractionated radiotherapy; acute toxicity; androgen suppression; high-risk prostate cancer; intensity-modulated radiotherapy