title: Pathophysiology and natural history of anorectal sequelae following radiation therapy for carcinoma of the prostate.
abstract: OBJECTIVE
  To characterize the prevalence, pathophysiology, and natural history of chronic radiation proctitis 5 years following radiation therapy (RT) for localized carcinoma of the prostate.
  
  
  METHODS
  Studies were performed in 34 patients (median age 68 years; range 54-79) previously randomly assigned to either 64 Gy in 32 fractions over 6.4 weeks or 55 Gy in 20 fractions over 4 weeks RT schedule using 2- and later 3-dimensional treatment technique for localized prostate carcinoma. Each patient underwent evaluations of (1) gastrointestinal (GI) symptoms (Modified Late Effects in Normal Tissues Subjective, Objective, Management and Analytic scales including effect on activities of daily living [ADLs]); (2) anorectal motor and sensory function (manometry and graded balloon distension); and (3) anal sphincteric morphology (endoanal ultrasound) before RT, at 1 month, and annually for 5 years after its completion.
  
  
  RESULTS
  Total GI symptom scores increased after RT and remained above baseline levels at 5 years and were associated with reductions in (1) basal anal pressures, (2) responses to squeeze and increased intra-abdominal pressure, (3) rectal compliance and (4) rectal volumes of sensory perception. Anal sphincter morphology was unchanged. At 5 years, 44% and 21% of patients reported urgency of defecation and rectal bleeding, respectively, and 48% impairment of ADLs. GI symptom scores and parameters of anorectal function and anal sphincter morphology did not differ between the 2 RT schedules or treatment techniques.
  
  
  CONCLUSIONS
  Five years after RT for prostate carcinoma, anorectal symptoms continue to have a significant impact on ADLs of almost 50% of patients. These symptoms are associated with anorectal dysfunction independent of the RT schedules or treatment techniques reported here.
authors: Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, Australia. eric.yeoh@health.sa.gov.au
authors: Eric K
authors: EK
authors: Yeoh
authors: Richard H
authors: RH
authors: Holloway
authors: Robert J
authors: RJ
authors: Fraser
authors: Rochelle J
authors: RJ
authors: Botten
authors: Addolorata C
authors: AC
authors: Di Matteo
authors: Julie
authors: J
authors: Butters
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001003:Anal Canal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000528:radiation effects*; D002277:Carcinoma / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D011349:Proctitis / Q000209:etiology / Q000503:physiopathology*; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000503:physiopathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000150:complications / Q000503:physiopathology*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000528:radiation effects*; D012018:Reflex / Q000502:physiology / Q000528:radiation effects; D012677:Sensation / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors; D014463:Ultrasonography