title: Toxicity and quality of life report of a phase II study of stereotactic body radiotherapy (SBRT) for low and intermediate risk prostate cancer.
abstract: BACKGROUND
  Clinical data indicates that delivery of larger daily doses of radiation may improve the therapeutic ratio for prostate cancer compared to conventional fractionation. A phase II study of stereotactic body radiotherapy with real-time motion management and daily plan re-optimization for low to intermediate risk prostate cancer was undertaken to evaluate this hypothesis. This report details the toxicity and quality of life following treatment.
  
  
  METHODS
  From 2009 to 2013, 60 patients with T1-T2c prostate cancer with a Gleason score of 6 and PSA ≤ 15 or Gleason score of 7 and PSA ≤ 10 were enrolled. Patients with nodal metastases, an American Urological Association symptom score > 18, or gland size > 100 g were not eligible. Patients were treated to 37 Gy in 5 fractions. Early and late genitourinary and gastrointestinal toxicity were graded based on NCI CTCAE v4.0 and quality of life was assessed by the American Urological Association symptom score, International Index of Erectile Function, and Expanded Prostate cancer Index Composite Short Form up to 36 months after treatment.
  
  
  RESULTS
  After a median follow-up of 27.6 months, no grade 3 or greater genitourinary toxicity was observed. Four patients (6.7%) reported a late grade 2 genitourinary toxicity. One patient (1.7%) reported a late grade 3 gastrointestinal toxicity. Five patients (8.3%) developed a late grade 2 gastrointestinal toxicity. The median American Urological Association symptom score increased from 4.5 prior to treatment to 11 while on treatment (p < 0.01), but was 5 at 36 months post-treatment (p = 0.65). Median International Index of Erectile Function scores decreased from 19 to 17 over the course of follow-up (p < 0.01). Only median scores within the Expanded Prostate Cancer Index Composite Short Form sexual domain were significantly decreased at 36 months post-treatment (67.9 vs 45.2, p = 0.02). There was no significant difference in median score within the urinary, bowel, or hormonal domains at 36 months of follow-up.
  
  
  CONCLUSIONS
  Stereotactic body radiotherapy for low to intermediate risk prostate cancer is well tolerated with limited toxicity or decrease in quality of life. Longer follow-up is necessary to assess the efficacy of treatment.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT00941915 Registered 17 June 2009.
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, DUMC Box 3085, Durham, NC, 27710, USA. matthew.boyer@dm.duke.edu.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Boyer
authors.affiliation: Coastal Carolina Radiation Oncology, Wilmington, NC, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Papagikos
authors.affiliation: Department of Radiation Oncology, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: Rex
authors.initials: R
authors.lastname: Kiteley
authors.affiliation: Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Vujaskovic
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, DUMC Box 3085, Durham, NC, 27710, USA.
authors.forename: Jackie
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, DUMC Box 3085, Durham, NC, 27710, USA.
authors.forename: W Robert
authors.initials: WR
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011788:Quality of Life; D016634:Radiosurgery / Q000009:adverse effects*; D011880:Radiotherapy Planning, Computer-Assisted
keywords: Prostate cancer; Quality of life; Stereotactic body radiation therapy; Toxicity