title: Increased chronic bowel complications with split-course pelvic irradiation.
abstract: OBJECTIVE
  To assess the possible impact of various treatment factors including split-course versus continuous course treatment on the incidence of chronic bowel complications in patients receiving adjuvant pelvic radiotherapy.
  
  
  METHODS
  A retrospective review was performed of records of 153 patients treated with adjuvant external beam pelvic radiation therapy without brachytherapy for endometrial and colorectal carcinomas. Continuous course radiotherapy was administered in 91 patients (59%) and 62 patients (41%) received split course treatment with a planned 2 week mid-treatment break. Mean pelvic dose and daily fraction size were 51.4 and 1.71 Gray, respectively. Multiple patient and treatment variables were assessed for their possible relationship to chronic bowel complications. Univariate and multivariate statistical analyses were carried out.
  
  
  RESULTS
  Twenty-seven patients (18%) developed chronic bowel complications at a median interval of 12 months after radiotherapy. Of all factors analyzed, only the use of split course technique was associated with a significantly higher rate of chronic bowel injury and decreased complication-free survival (p = 0.009).
  
  
  CONCLUSIONS
  This study supports earlier suggestions that the use of split course rather than continuous course pelvic radiotherapy can increase late intestinal complication rates. Possible pathophysiologic mechanisms are discussed.
authors.affiliation: Department of Radiology (Radiation Oncology), Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157.
authors.forename: W R
authors.initials: WR
authors.lastname: Sigmon
authors.forename: M E
authors.initials: ME
authors.lastname: Randall
authors.forename: W W
authors.initials: WW
authors.lastname: Olds
authors.forename: A J
authors.initials: AJ
authors.lastname: McCunniff
authors.forename: W H
authors.initials: WH
authors.lastname: St Clair
authors.forename: T E
authors.initials: TE
authors.lastname: Craven
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D015179:Colorectal Neoplasms / Q000532:radiotherapy; D016889:Endometrial Neoplasms / Q000532:radiotherapy; D005260:Female; D006801:Humans; D007410:Intestinal Diseases / Q000209:etiology*; D008875:Middle Aged; D010388:Pelvis / Q000528:radiation effects*; D011878:Radiotherapy / Q000009:adverse effects* / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies