title: The therapeutic and adverse effects of modified radiation fields for patients with rectal cancer.
abstract: OBJECTIVE
  To compare the therapeutic effect and complications of modified radiation fields (MRFs) with those of conventional pelvic radiation fields (CPRFs) for rectal cancer.
  
  
  METHODS
  From December 1996 to October 2009, a total of 160 patients with rectal carcinoma who received total mesorectal excision and postoperative radiotherapy were examined. Ninety-four patients were in the CPRFs group, and 66 were in the MRFs group. The dose was 50 Gy per 25 fractions in the initial plan.
  
  
  RESULTS
  The treatment volume and the volume of small bowel that received more than 15 Gy of the MRFs was smaller than that of the CPRFs (P < .001). The rates of local recurrence, overall survival, and disease-free survival were not statistically significant between the MRFs and CPRFs groups (P > .05). There was a statistical difference (P < .05) in the incidence of acute toxicity, which included serious complications in the lower digestive tract (grade ≥3). The completion rate for the initial radiotherapy plan was higher in the MRFs group than in the CPRFs group (P = .027).
  
  
  CONCLUSIONS
  Compared with CPRFs, MRFs manifested a lower incidence of complications and the same therapeutic effects. This finding will facilitate the clinical application of MRFs for patients with rectal cancer.
authors: Department of Radiation Oncology, Zhong Shan Hospital, Fudan University, Shanghai, China.
authors: Bin-Liang
authors: BL
authors: Wang
authors: Wei
authors: W
authors: Jiang
authors: Shi-Suo
authors: SS
authors: Du
authors: Jian-Min
authors: JM
authors: Xu
authors: Zhao-Chong
authors: ZC
authors: Zeng
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002288:Adenocarcinoma, Mucinous / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000231:Adenocarcinoma, Papillary / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D010388:Pelvis / Q000528:radiation effects*; D011379:Prognosis; D011880:Radiotherapy Planning, Computer-Assisted; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D014481:United States