title: The anal canal as a risk organ in cervical cancer patients with hemorrhoids undergoing whole pelvic radiotherapy.
abstract: OBJECTIVE
  Tolerance of the anal canal tends to be ignored in patients with cervical cancer undergoing whole pelvic radiotherapy. However, patients with hemorrhoids may be troubled with low radiation dose. We tried to analyze the dose-volume statistics of the anal canal in patients undergoing whole pelvic radiotherapy.
  
  
  METHODS
  The records of 31 patients with cervical cancer who received definite or postoperative radiotherapy at one institution were reviewed. Acute anal symptoms, such as anal pain and bleeding, were evaluated from radiotherapy start to 1 month after radiotherapy completion. Various clinical and dosimetric factors were analyzed to characterize relations with acute anal complications.
  
  
  RESULTS
  The anal verge was located an average of 1.2 cm (range -0.6~3.9) below the lower border of the ischial tuberosity and an average of 2.7 cm (range -0.6~5.7) behind the sacral promontory level. The presence of hemorrhoids before radiotherapy was found to be significantly associated with acute radiation-induced anal symptoms (p = 0.001), and the mean induction dose for anal symptoms was 36.9 Gy. No patient without hemorrhoids developed an anal symptom during radiotherapy. Dosimetric analyses of V30 and V40 showed marginal correlations with anal symptoms (p = 0.07).
  
  
  CONCLUSIONS
  The present study suggests a relation between acute anal symptoms following radiotherapy and acute hemorrhoid aggravation. Furthermore, the location of the anal verge was found to be variable, and consequently doses administered to the anal canal also varied substantially. Our results caution careful radiation treatment planning for whole pelvic radiotherapy, and that proper clinical management be afforded patients with hemorrhoids during radiotherapy.
authors.affiliation: Department of Radiation Oncology, Dongguk University School of Medicine, Gyeongju - Korea.
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Jang
authors.forename: Jong Geun
authors.initials: JG
authors.lastname: Baek
authors.forename: Sunmi
authors.initials: S
authors.lastname: Jo
mesh_terms: D000368:Aged; D001003:Anal Canal / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects*; D005260:Female; D006484:Hemorrhoids / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008499:Medical Records; D008875:Middle Aged; D009367:Neoplasm Staging; D010388:Pelvis; D011832:Radiation Injuries / Q000209:etiology*; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D018401:Sample Size; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000150:complications / Q000532:radiotherapy*