title: Computed tomography-based high-dose-rate intracavitary brachytherapy for uterine cervical cancer: preliminary demonstration of correlation between dose-volume parameters and rectal mucosal changes observed by flexible sigmoidoscopy.
abstract: OBJECTIVE
  To compare the dose-volume histogram (DVH) parameters obtained by three-dimensional gynecologic brachytherapy planning with the rectosigmoid mucosal changes observed by flexible sigmoidoscopy.
  
  
  METHODS
  Between January 2004 and July 2005, 71 patients with International Federation of Gynecology and Obstetrics Stage IB-IIIB uterine cervical cancer underwent computed tomography-based high-dose-rate intracavitary brachytherapy. The total dose (external beam radiotherapy [RT] plus intracavitary brachytherapy) to the International Commission of Radiation Units and Measurements rectal point (ICRU(RP)) and DVH parameters for rectosigmoid colon were calculated using the equivalent dose in 2-Gy fractions (alpha/beta = 3 Gy). Sigmoidoscopy was performed every 6 months after RT, with the 6-scale scoring system used to determine mucosal changes.
  
  
  RESULTS
  The mean values of the DVH parameters and ICRU(RP) were significantly greater in patients with a score of > or =2 than in those with a score <2 at 12 months after RT (ICRU(RP), 71 Gy(alpha/beta3) vs. 66 Gy(alpha/beta3), p = 0.02; D(0.1cc), 93 Gy(alpha/beta3) vs. 85 Gy(alpha/beta3), p = 0.04; D(1cc), 80 Gy(alpha/beta3) vs. 73 Gy(alpha/beta3), p = 0.02; D(2cc), 75 Gy(alpha/beta3) vs. 69 Gy(alpha/beta3), p = 0.02). The probability of a score of > or =2 showed a significant relationship with the DVH parameters and ICRU(RP) (ICRU(RP), p = 0.03; D(0.1cc), p = 0.05; D(1cc), p = 0.02; D(2cc), p = 0.02).
  
  
  CONCLUSIONS
  Our preliminary data have shown that DVH values of the rectosigmoid colon obtained by computed tomography-based three-dimensional brachytherapy planning are reliable and predictive of score > or =2 rectosigmoid mucosal changes.
authors.affiliation: Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, South Korea.
authors.forename: Woong Sub
authors.initials: WS
authors.lastname: Koom
authors.forename: Dae Kyung
authors.initials: DK
authors.lastname: Sohn
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Yoon
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Myonggeun
authors.initials: M
authors.lastname: Yoon
authors.forename: Dongho
authors.initials: D
authors.lastname: Shin
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Park
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Cho
mesh_terms: D000230:Adenocarcinoma / Q000532:radiotherapy; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy; D016009:Chi-Square Distribution; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000528:radiation effects*; D008875:Middle Aged; D011446:Prospective Studies; D011832:Radiation Injuries / Q000473:pathology*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012007:Rectum / Q000473:pathology / Q000528:radiation effects*; D012044:Regression Analysis; D012812:Sigmoidoscopy; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*