title: Difference in the rate of rectal complications following prostate brachytherapy based on the prostate-rectum distance and the prostate longitudinal length among early prostate cancer patients.
abstract: OBJECTIVE
  To investigate the difference in rectal complications rate following prostate low dose rate (LDR) brachytherapy based on prostate-rectum distance and prostate longitudinal length among early prostate cancer patients.
  
  
  METHODS
  From March 2008 to February 2013, 245 prostate cancer patients with a Gleason score ≤7 were treated with 125-I LDR brachytherapy. Among them, 178 patients with prostate volume 20-35 mL and a follow-up period ≥6 months were evaluated for radiation proctitis. Magnetic resonance imaging (MRI) was performed for a prebrachytherapy evaluation, and prostate-rectum distance and prostate longitudinal length were measured. The radiation proctitis was confirmed and graded via colonoscopy based on the radiation therapy oncology group (RTOG) toxicity criteria.
  
  
  RESULTS
  Twenty-three patients received a colonoscopy for proctitis evaluation, and 12 were identified as grade 1 on the RTOG scale. Nine patients were diagnosed as grade 2 and 2 patients were grade 3. No patient developed grade 4 proctitis. The rectal-complication group had a mean prostate-rectum distance of 2.51±0.16 mm, while non-rectal-complication control group had 3.32±0.31 mm. The grade 1 proctitis patients had a mean prostate-rectum distance of 2.80±0.15 mm, which was significantly longer than 2.12±0.31 mm of grades 2 and 3 patient groups (p=0.045). All 11 patients of grades 2 and 3 had a prostate longitudinal length of 35.22±2.50 mm, which was longer than group 1, but the difference was not statistically significant (p=0.214).
  
  
  CONCLUSIONS
  As the prostate-rectum distance increased, fewer postimplantation rectal symptoms were observed. Patients with a shorter prostate-rectum distance in MRI should receive modified implantation techniques or radical prostatectomy.
authors.affiliation: Department of Urology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Moon Hyung
authors.initials: MH
authors.lastname: Kang
authors.affiliation: Department of Urology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Young Dong
authors.initials: YD
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Shin
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Oh
authors.affiliation: Department of Urology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Park
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects*; D002277:Carcinoma / Q000532:radiotherapy*; D003113:Colonoscopy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011349:Proctitis / Q000175:diagnosis / Q000209:etiology*; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology*; D012720:Severity of Illness Index
keywords: Brachytherapy; Proctitis; Prostatic neoplasms