title: Prospective comparison of rectal dose reduction during intracavitary brachytherapy for cervical cancer using three rectal retraction techniques.
abstract: To compare three rectal retraction methods on dose to organs at risk, focusing on rectal dose, in cervix cancer patients treated with high-dose-rate intracavitary brachytherapy.
  
  
  
  A prospective study was conducted on patients with cervical carcinoma treated with chemoradiotherapy, including external beam radiation and four fractions of high-dose-rate intracavitary brachytherapy prescribed to Point A using a ring and tandem applicator under conscious sedation. Rectal retraction methods included: a rectal retractor blade (RR), vaginal gauze packing (VP), and a tandem Foley balloon (FB). All three methods were used in all patients. The RR was used first, and the following applications were randomly assigned to VP or FB. CT planning was used to calculate D2cc for rectum, sigmoid, small bowel, and bladder. The Wilcoxon signed rank test was used to determine if the median dose differences between methods were statistically significant.
  
  
  
  In these 11 patients, median dose (min, max) in cGy to the rectum using RR, FB, and VP was 131 (102, 165), 199 (124, 243), and 218 (149, 299), respectively. The RR demonstrated lower median intrapatient doses to rectum compared with FB and VP (-55 cGy; p = 0.014 and -76 cGy; p = 0.004, respectively). The RR also resulted in lower sigmoid doses. No differences in dose were observed between the VP and FB methods.
  
  
  
  The rectal retractor significantly reduced the dose to rectum and sigmoid compared with FP and VP. In patients treated under conscious sedation, the RR method provides the best rectal sparing. There were no significant differences in dose observed between the FB and VP techniques.
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada. Electronic address: kongi@hhsc.ca.
authors.forename: Iwa
authors.initials: I
authors.lastname: Kong
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada.
authors.forename: Sachi
authors.initials: S
authors.lastname: Vorunganti
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada.
authors.forename: Malti
authors.initials: M
authors.lastname: Patel
authors.affiliation: Department of Medical Physics, Juravinski Cancer Centre, Hamilton, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Farrell
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada.
authors.forename: Emilia
authors.initials: E
authors.lastname: Timotin
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada.
authors.forename: Sean
authors.initials: S
authors.lastname: Quinlan-Davidson
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada; Escarpment Cancer Research Institute, McMaster University, Hamilton, Canada.
authors.forename: Greg
authors.initials: G
authors.lastname: Pond
authors.affiliation: Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Canada.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Sur
authors.affiliation: Department of Medical Physics, Juravinski Cancer Centre, Hamilton, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Hunter
mesh_terms: D000230:Adenocarcinoma / Q000628:therapy*; D000328:Adult; D001918:Brachytherapy / Q000379:methods*; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D059248:Chemoradiotherapy / Q000379:methods; D012809:Colon, Sigmoid; D005260:Female; D006801:Humans; D008875:Middle Aged; D058958:Organs at Risk; D011446:Prospective Studies; D011878:Radiotherapy; D011879:Radiotherapy Dosage; D012007:Rectum; D013525:Surgical Instruments; D001743:Urinary Bladder; D002583:Uterine Cervical Neoplasms / Q000628:therapy*
keywords: Brachytherapy; Cervical cancer; Rectal dose; Retractor