title: Severe rectal complications after prostate brachytherapy.
abstract: OBJECTIVE
  Some investigators have reported severe rectal complications after brachytherapy. Due to the low number of such events, their relationship to dosimetric parameters has not been well characterized.
  
  
  METHODS
  A total of 3126 patients were treated with low dose rate brachytherapy from 1998 through 2010. 2464 had implant alone, and 313 had implant preceded by 44-46Gy supplemental external beam radiation (EBRT). Post-implant dosimetry was based on a CT scan obtained on the day of implant, generally within 30min of the procedure. Every patient's record was reviewed for occurrence of rectal complications.
  
  
  RESULTS
  Eight of 2464 patients (0.32%) treated with brachytherapy alone developed a radiation-related rectal fistula. Average prostatic and rectal dose parameters were moderately higher for fistula patients than for patients without a severe rectal complication. For instance, the average R100 was 1.2±0.75cc for fistula patients, versus 0.37±0.88cc for non-fistula patients. However, the fistula patients' values were well within the range of values for patients without a rectal complication. Four patients had some attempt at repair or reconstruction, but long-term functional outcomes were not favorable.
  
  
  CONCLUSIONS
  Rectal fistulas are a very uncommon potential complication of prostate brachytherapy, which can occur even in the setting of acceptable day 0 rectal doses. Their occurrence is not easily explained by standard dosimetric or clinical factors.
authors.affiliation: Radiation Oncology Service, Department of Veterans Affairs Medical Center, Seattle, United States. Electronic address: Kent.wallner@va.gov.
authors.forename: Kent
authors.initials: K
authors.lastname: Wallner
authors.affiliation: Radiation Oncology Service, Department of Veterans Affairs Medical Center, Seattle, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sutlief
authors.affiliation: Radiation Oncology Service, Department of Veterans Affairs Medical Center, Seattle, United States.
authors.forename: Carl
authors.initials: C
authors.lastname: Bergsagel
authors.affiliation: Urologic Research Institute, Wheeling Jesuit University, United States.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Merrick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology*; D011874:Radiometry / Q000379:methods; D012002:Rectal Diseases / Q000209:etiology*; D012007:Rectum / Q000528:radiation effects*
keywords: Brachytherapy; Complications; Prostate; Rectal