title: A prospective longitudinal survey of erectile dysfunction in patients with localized prostate cancer treated with permanent prostate brachytherapy.
abstract: OBJECTIVE
  Few studies have evaluated changes in erectile function with time before and after prostate brachytherapy using the International Index of Erectile Function-15, a sensitive, validated tool for assessing male sexual dysfunction. In this prospective study we evaluated the natural history of erectile function after prostate brachytherapy without supplemental therapy (external beam radiotherapy, phosphodiesterase-5 inhibitors or androgen deprivation therapy) using the International Index of Erectile Function-15.
  
  
  METHODS
  We identified 119 patients who were followed at least 12 months after prostate brachytherapy between 2004 and 2010. Sexual and erectile function status were assessed before brachytherapy (baseline), and 3, 6, 12, 18, 24 and 36 months postoperatively using the International Index of Erectile Function-15.
  
  
  RESULTS
  Mean total International Index of Erectile Function-15 score, and scores on the erectile function, orgasmic function, sexual desire and intercourse satisfaction domains 3 months after brachytherapy were significantly lower than at baseline (p <0.05). They remained lower until 36 months after prostate brachytherapy. Erectile function was maintained 12 months after brachytherapy in 16 of the 48 men (33.3%) with a baseline erectile function domain score of 11 or greater. There was no significant difference in clinical features except the age of patients who maintained the erectile function domain score and their counterparts 12 months after brachytherapy. Multivariate analysis revealed that age 70 years or greater was the only predictive factor for deteriorating erectile function after brachytherapy (p = 0.035).
  
  
  CONCLUSIONS
  Findings indicate a global decrease in all domains of the International Index of Erectile Function-15 score 12 months after prostate brachytherapy. Also, patient age may influence the preservation of brachytherapy related potency.
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Matsushima
authors.forename: Eiji
authors.initials: E
authors.lastname: Kikuchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Maeda
authors.forename: Jun
authors.initials: J
authors.lastname: Nakashima
authors.forename: Akitomo
authors.initials: A
authors.lastname: Sugawara
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ando
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Mizuno
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Nagata
authors.forename: Akira
authors.initials: A
authors.lastname: Miyajima
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Shigematsu
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Oya
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects*; D019160:Endosonography; D007172:Erectile Dysfunction / Q000209:etiology* / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection / Q000528:radiation effects*; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000532:radiotherapy*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome