title: Analysis of the impact of androgen deprivation therapy on sildenafil citrate response following radiation therapy for prostate cancer.
abstract: OBJECTIVE
  Radiation therapy is a widely accepted strategy for prostate cancer. Erectile dysfunction is a common complication of radiation therapy. Adjuvant androgen deprivation was shown to prolong survival in select patients. There is controversy regarding the impact of androgen deprivation on erectile function. We defined the impact of androgen deprivation on the sildenafil response in patients with erectile dysfunction following radiation therapy.
  
  
  METHODS
  Patients were enrolled prospectively if they underwent radiation therapy in the form of 3-dimensional conformal external beam or brachytherapy with or without androgen deprivation, reported functional erections before radiation therapy, experienced the onset of erectile dysfunction following the completion of radiation therapy, had comprehensive erectile dysfunction evaluation, including a thorough history and physical examination, attempted sildenafil periodically and completed the International Index of Erectile Function on at least 2 occasions throughout the first 3 years following the completion of radiation therapy.
  
  
  RESULTS
  A total of 152 patients were enrolled. Mean age +/- SD was 62 +/- 14 years. No significant difference existed in age or radiation dose between patients with and without androgen deprivation exposure. Mean androgen deprivation duration was 3.8 +/- 1.8 months. For patients with conformal external beam and brachytherapy the sildenafil response, mean erectile function domain score and percent who experienced erectile function domain normalization at each time point were lower in those with vs without androgen deprivation.
  
  
  CONCLUSIONS
  Androgen deprivation seems to exert a deleterious effect on erectile function in men undergoing radiation therapy for prostate cancer. This was observed in men treated with conformal external beam and brachytherapy at short-term, medium term and long-term followup.
authors.affiliation: Department of Urology, Weill Medical College of Cornell University, New York, New York, USA.
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Teloken
authors.forename: Michael
authors.initials: M
authors.lastname: Ohebshalom
authors.forename: Najeeb
authors.initials: N
authors.lastname: Mohideen
authors.forename: John P
authors.initials: JP
authors.lastname: Mulhall
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000008:administration & dosage*; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010413:Penis / Q000098:blood supply / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage; D010879:Piperazines / Q000008:administration & dosage*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D011687:Purines / Q000008:administration & dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D018570:Risk Assessment; D000068677:Sildenafil Citrate; D018709:Statistics, Nonparametric; D013450:Sulfones / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D017430:Prostate-Specific Antigen