title: Late genitourinary and gastrointestinal toxicity after magnetic resonance image-guided prostate brachytherapy with or without neoadjuvant external beam radiation therapy.
abstract: BACKGROUND
  This study was designed to estimate the rates of late genitourinary (GU) and rectal toxicity after magnetic resonance image (MRI)-guided prostate brachytherapy exclusively or in conjunction with external beam radiation therapy (EBRT).
  
  
  METHODS
  Between November 1997 and April 2002, 201 patients with category T1C prostate carcinoma (according to the 2002 American Joint Committee on Cancer staging criteria), prostate specific antigen levels < 10 ng/mL, and biopsy Gleason score 3 + 4 disease were treated with MRI-guided brachytherapy exclusively or in conjunction with EBRT. The MRI-guided technique was designed to spare the urethra based on delivery of the prescription dose to the peripheral zone exclusively. The Kaplan-Meier method was used to estimate rates of freedom from late GU and rectal toxicity. Comparisons were made using a log-rank test.
  
  
  RESULTS
  At a median follow-up of 2.8 years (range, 0.5-5.0 years), the 4-year estimates of rectal bleeding requiring coagulation for patients who underwent implantation therapy, compared with patients who received combined-modality therapy, were 8% versus 30%, respectively (log-rank P value = 0.0001). Although erectile dysfunction was common (range, 82-93%), with the use of sildenafil citrate (Viagra), it was estimated that at least two-thirds of patients had erectile function comparable to or superior to baseline function, independent of whether they received monotherapy or combined-modality therapy (P = 0.46). The 4-year estimate of freedom from radiation cystitis was 100% versus 95% (P = 0.01) for patients who received monotherapy and patients who received combined-modality therapy, respectively. No urethral strictures were observed, and no patients underwent postimplantation transurethral resection of the prostate.
  
  
  CONCLUSIONS
  In the current study, rectal bleeding after MRI-guided prostate brachymonotherapy was infrequent, and urethral and bladder toxicity is reported to be rare and may be attributed to the urethral-sparing technique of the MRI-guided approach.
authors.affiliation: Department of Radiation Oncology, Brigham and Women's Hospital, 75 Francis Street, L-2 Level, Boston, MA 02115, USA. malbert@lroc.harvard.edu
authors.forename: Michele
authors.initials: M
authors.lastname: Albert
authors.forename: Clare M
authors.initials: CM
authors.lastname: Tempany
authors.forename: Delray
authors.initials: D
authors.lastname: Schultz
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Chen
authors.forename: Robert A
authors.initials: RA
authors.lastname: Cormack
authors.forename: Sanjaya
authors.initials: S
authors.lastname: Kumar
authors.forename: Mark D
authors.initials: MD
authors.lastname: Hurwitz
authors.forename: Clair
authors.initials: C
authors.lastname: Beard
authors.forename: Kemal
authors.initials: K
authors.lastname: Tuncali
authors.forename: Michael
authors.initials: M
authors.lastname: O'Leary
authors.forename: George P
authors.initials: GP
authors.lastname: Topulos
authors.forename: Kristin
authors.initials: K
authors.lastname: Valentine
authors.forename: Lynn
authors.initials: L
authors.lastname: Lopes
authors.forename: Angela
authors.initials: A
authors.lastname: Kanan
authors.forename: Daniel
authors.initials: D
authors.lastname: Kacher
authors.forename: James
authors.initials: J
authors.lastname: Rosato
authors.forename: Hanne
authors.initials: H
authors.lastname: Kooy
authors.forename: Ferenc
authors.initials: F
authors.lastname: Jolesz
authors.forename: David L
authors.initials: DL
authors.lastname: Carr-Locke
authors.forename: Jerome P
authors.initials: JP
authors.lastname: Richie
authors.forename: Anthony V
authors.initials: AV
authors.lastname: D'Amico
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D002277:Carcinoma / Q000532:radiotherapy*; D005500:Follow-Up Studies; D006471:Gastrointestinal Hemorrhage / Q000209:etiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries; D012007:Rectum / Q000473:pathology*; D014521:Urethra / Q000473:pathology*; D001743:Urinary Bladder / Q000473:pathology*