title: Dosimetric analysis of urethral strictures following HDR (192)Ir brachytherapy as monotherapy for intermediate- and high-risk prostate cancer.
abstract: OBJECTIVE
  To evaluate dosimetric parameters related to urethral strictures following high dose-rate brachytherapy (HDRBT) alone for prostate cancer.
  
  
  METHODS
  Ten strictures were identified in 213 patients treated with HDRBT alone receiving 34Gy in four fractions, 36Gy in four fractions, 31.5Gy in 3 fractions or 26Gy in 2 fractions. A matched-pair analysis used 2 controls for each case matched for dose fractionation schedule, pre-treatment IPSS score, number of needles used and clinical target volume. The urethra was divided into membranous urethra and inferior, mid and superior thirds of the prostatic urethra.
  
  
  RESULTS
  Stricture rates were 3% in the 34Gy group, 4% in the 36Gy group, 6% in the 31.5Gy group and 4% in the 26Gy group. The median time to stricture formation was 26months (range 8-40). The dosimetric parameters investigated were not statistically different between cases and controls. No correlation was seen between stricture rate and fractionation schedule.
  
  
  CONCLUSIONS
  Urethral stricture is an infrequent complication of prostate HDRBT when used to deliver high doses as sole treatment, with an overall incidence in this cohort of 10/213 (4.7%). In a matched pair analysis no association with dose schedule or urethral dosimetry was identified, but the small number of events limits definitive conclusions.
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK. Electronic address: patricia.diez@nhs.net.
authors.forename: Patricia
authors.initials: P
authors.lastname: Díez
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Vinod
authors.initials: V
authors.lastname: Mullassery
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Pittaya
authors.initials: P
authors.lastname: Dankulchai
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Ostler
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Hughes
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Roberto
authors.initials: R
authors.lastname: Alonzi
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Gerry
authors.initials: G
authors.lastname: Lowe
authors.affiliation: Mount Vernon Cancer Centre, Northwood, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hoskin
mesh_terms: D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D005500:Follow-Up Studies; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D014521:Urethra / Q000528:radiation effects; D014525:Urethral Stricture / Q000209:etiology*
chemical_list: D007496:Iridium Radioisotopes
keywords: Brachytherapy; Dosimetry; HDR; Monotherapy; Prostate cancer; Urethral stricture