title: Erectile function following external beam radiotherapy for clinically organ-confined or locally advanced prostate cancer.
abstract: BACKGROUND
  External beam radiotherapy (XRT) has been a standard treatment for clinically localized prostate cancer. However, preservation of erectile function following XRT is controversial. In this study, the influence of XRT on erectile function of patients with clinically organ-confined or locally advanced prostate cancer was retrospectively evaluated.
  
  
  METHODS
  The study included 34 of 84 patients with organ-confined or locally advanced prostate cancer who underwent XRT between 1995 and 2002. Erectile function following radiotherapy was assessed by a simple mailed questionnaire that was constructed for the study. To determine the predictive factors for erectile dysfunction following radiotherapy, data were analyzed by multivariate analysis with the Cox proportional hazards model.
  
  
  RESULTS
  The modality of XRT was the only factor to independently predict erectile dysfunction following XRT. The maintenance rates of erectile function were 47.6% at 1 year and 19% at 3 years in patients who received the 3-dimensional conformal radiotherapy, which were significantly higher than in those who received conventional radiotherapy (P = 0.026).
  
  
  CONCLUSIONS
  XRT significantly reduced the maintenance rate of erectile function during the follow-up period, with the rate being 19% at 3 years in patients who received 3-dimensional conformal radiation. The XRT modality was involved in the reduction of erectile function. These results suggest that erectile dysfunction is a possible adverse event following XRT.
authors.affiliation: Department of Urology, Sapporo Medical University, Sapporo, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Hisasue
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Naoya
authors.initials: N
authors.lastname: Masumori
authors.forename: Naoki
authors.initials: N
authors.lastname: Itoh
authors.forename: Noriomi
authors.initials: N
authors.lastname: Miyao
authors.forename: Keiji
authors.initials: K
authors.lastname: Takatsuka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yanase
authors.forename: Atsushi
authors.initials: A
authors.lastname: Oouchi
authors.forename: Masato
authors.initials: M
authors.lastname: Hareyama
authors.forename: Taiji
authors.initials: T
authors.lastname: Tsukamoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D007172:Erectile Dysfunction / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection / Q000528:radiation effects*; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires