title: Improving the preservation of erectile function after external beam radiation therapy for prostate cancer.
abstract: OBJECTIVE
  To investigate whether the type of collimation technique, target dose and treated volume influence the prevalence of intact erectile function after external beam radiation therapy for localized prostate cancer.
  
  
  METHODS
  A prospective study was conducted to assess erection stiffness before treatment and after follow-ups of 9-18 months and 4-5.5 years. Information was collected using the Radiumhemmet Scale of Sexual Function.
  
  
  RESULTS
  Thirty-one men were 'potent' before the radiation. Fourteen of them were treated with a conventional collimator and 17 were given three-dimensional conformal therapy with the aid of a multileaf collimator. Preserved erectile function at 9-18 months was found in 17 of the 31 men (55%) and at the 4-5-year follow-up in five of 22 (23%). Preservation of potency was related to the treatment procedure but not to the treatment volume.
  
  
  CONCLUSIONS
  Conformal therapy may increase the percentage of men preserving erectile function during radiotherapy for localized prostate cancer; it is possible that the differences to conventional therapy do not depend on treated volume.
authors.affiliation: Department of Oncology and Pathology, Clinical Cancerepidemiology, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: al-Abany
authors.forename: G
authors.initials: G
authors.lastname: Steineck
authors.forename: A K
authors.initials: AK
authors.lastname: Agren Cronqvist
authors.forename: A R
authors.initials: AR
authors.lastname: Helgason
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000175:diagnosis / Q000532:radiotherapy*; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D004307:Dose-Response Relationship, Radiation; D007172:Erectile Dysfunction / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000150:complications / Q000175:diagnosis / Q000532:radiotherapy*; D011829:Radiation Dosage; D011878:Radiotherapy / Q000009:adverse effects* / Q000379:methods*; D018570:Risk Assessment