title: The radiation-induced changes in rectal mucosa: hyperfractionated vs. hypofractionated preoperative radiation for rectal cancer.
abstract: OBJECTIVE
  The purpose of the study was the qualitative and quantitative evaluation of acute radiation-induced rectal changes in patients who underwent preoperative radiotherapy according to two different irradiation protocols.
  
  
  METHODS
  Sixty-eight patients with rectal adenocarcinoma underwent preoperative radiotherapy; 44 and 24 patients underwent hyperfractionated and hypofractionated protocol, respectively. Fifteen patients treated with surgery alone served as a control group. Five basic histopathologic features (meganucleosis, inflammatory infiltrations, eosinophils, mucus secretion, and erosions) and two additional features (mitotic figures and architectural glandular abnormalities) of radiation-induced changes were qualified and quantified.
  
  
  RESULTS
  Acute radiation-induced reactions were found in 66 patients. The most common were eosinophilic and plasma-cell inflammatory infiltrations (65 patients), erosions, and decreased mucus secretion (54 patients). Meganucleosis and mitotic figures were more common in patients who underwent hyperfractionated radiotherapy. The least common were the glandular architectural distortions, especially in patients treated with hypofractionated radiotherapy. Statistically significant differences in morphologic parameters studied between groups treated with different irradiation protocols were found.
  
  
  CONCLUSIONS
  The system of assessment is a valuable tool in the evaluation of radiation-induced changes in the rectal mucosa. A greater intensity of regenerative changes was found in patients treated with hyperfractionated radiotherapy.
authors.affiliation: Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec, Poland.
authors.forename: Jacek J
authors.initials: JJ
authors.lastname: Starzewski
authors.forename: Jacek T
authors.initials: JT
authors.lastname: Pajak
authors.forename: Iwona
authors.initials: I
authors.lastname: Pawełczyk
authors.forename: Dariusz
authors.initials: D
authors.lastname: Lange
authors.forename: Dariusz
authors.initials: D
authors.lastname: Gołka
authors.forename: Monika
authors.initials: M
authors.lastname: Brzezińska
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Lorenc
mesh_terms: D000230:Adenocarcinoma / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy / Q000379:methods; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011832:Radiation Injuries / Q000473:pathology*; D012004:Rectal Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D012007:Rectum / Q000473:pathology / Q000528:radiation effects*