title: Outcomes after intensity-modulated versus conformal radiotherapy in older men with nonmetastatic prostate cancer.
abstract: OBJECTIVE
  There is little evidence comparing complications after intensity-modulated (IMRT) vs. three-dimensional conformal radiotherapy (CRT) for prostate cancer. The study objective was to test the hypothesis that IMRT, compared with CRT, is associated with a reduction in bowel, urinary, and erectile complications in elderly men with nonmetastatic prostate cancer.
  
  
  METHODS
  We undertook an observational cohort study using registry and administrative claims data from the SEER-Medicare database. We identified men aged 65 years or older diagnosed with nonmetastatic prostate cancer in the United States between 2002 and 2004 who received IMRT (n = 5,845) or CRT (n = 6,753). The primary outcome was a composite measure of bowel complications. Secondary outcomes were composite measures of urinary and erectile complications. We also examined specific subsets of bowel (proctitis/hemorrhage) and urinary (cystitis/hematuria) events within the composite complication measures.
  
  
  RESULTS
  IMRT was associated with reductions in composite bowel complications (24-month cumulative incidence 18.8% vs. 22.5%; hazard ratio [HR] 0.86; 95% confidence interval [CI], 0.79-0.93) and proctitis/hemorrhage (HR 0.78; 95% CI, 0.64-0.95). IMRT was not associated with rates of composite urinary complications (HR 0.93; 95% CI, 0.83-1.04) or cystitis/hematuria (HR 0.94; 95% CI, 0.83-1.07). The incidence of erectile complications involving invasive procedures was low and did not differ significantly between groups, although IMRT was associated with an increase in new diagnoses of impotence (HR 1.27, 95% CI, 1.14-1.42).
  
  
  CONCLUSIONS
  IMRT is associated with a small reduction in composite bowel complications and proctitis/hemorrhage compared with CRT in elderly men with nonmetastatic prostate cancer.
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA. bekelman@uphs.upenn.edu
authors.forename: Justin E
authors.initials: JE
authors.lastname: Bekelman
authors.forename: Nandita
authors.initials: N
authors.lastname: Mitra
authors.forename: Jason
authors.initials: J
authors.lastname: Efstathiou
authors.forename: Kaijun
authors.initials: K
authors.lastname: Liao
authors.forename: Robert
authors.initials: R
authors.lastname: Sunderland
authors.forename: Deborah N
authors.initials: DN
authors.lastname: Yeboa
authors.forename: Katrina
authors.initials: K
authors.lastname: Armstrong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D007172:Erectile Dysfunction / Q000209:etiology; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007422:Intestines / Q000528:radiation effects*; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D011349:Proctitis / Q000209:etiology; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000150:complications*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000379:methods; D018426:SEER Program; D014481:United States; D014555:Urination Disorders / Q000209:etiology