title: Long-term erectile function following permanent seed brachytherapy treatment for localized prostate cancer.
abstract: OBJECTIVE
  Erectile function (EF) is commonly affected following prostate cancer treatment. We aim to evaluate the long-term EF following seed brachytherapy (BT) treatment.
  
  
  METHODS
  The study consisted of 366 patients treated with BT at our institution, who completed the IIEF-5 questionnaire and reported no or mild erectile dysfunction (ED) pre-BT. The probability of EF preservation post-BT was estimated using the Kaplan-Meier methods. The difference in EF preservation by patient-, tumour- and treatment-related factors was assessed using the log-rank test. Multivariate Cox regression was used to estimate the effect of each factor on EF preservation.
  
  
  RESULTS
  Of the 366 patients, 277 (76%) reported normal EF, and 89 (24%) reported mild ED. The patients were followed-up for a median of 41 months (range: 3-124), and the 5-year actuarial rate of EF preservation was 59%. Age at BT seed implant, presence of medical comorbidities, Gleason score and the biologically effective dose (BED) are associated with EF preservation (P < 0.005). The association for these four factors remains statistically significant in multivariate analysis, with Gleason score having the strongest effect (HR = 3.7; 95% CI = 2.6-5.4).
  
  
  CONCLUSIONS
  The 5-year actuarial rate of EF preservation post-BT in our cohort is 59%, and is influenced by multiple factors.
authors.affiliation: William Buckland Radiotherapy Centre, Alfred Health, Melbourne, Australia; Department of Public Health and Primary Care, University of Cambridge, United Kingdom.
authors.forename: Wee Loon
authors.initials: WL
authors.lastname: Ong
authors.affiliation: William Buckland Radiotherapy Centre, Alfred Health, Melbourne, Australia.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Hindson
authors.affiliation: William Buckland Radiotherapy Centre, Alfred Health, Melbourne, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Beaufort
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Pharoah
authors.affiliation: William Buckland Radiotherapy Centre, Alfred Health, Melbourne, Australia; Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia. Electronic address: Jeremy.millar@monash.edu.
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Millar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects*; D015331:Cohort Studies; D007172:Erectile Dysfunction / Q000188:drug therapy / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010410:Penile Erection / Q000502:physiology / Q000528:radiation effects; D058986:Phosphodiesterase 5 Inhibitors / Q000627:therapeutic use; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D058986:Phosphodiesterase 5 Inhibitors
keywords: Brachytherapy; Erectile function; Prostate cancer