title: Bladder-Rectum Spacer Balloon versus Vaginal Gauze Packing in High Dose Rate Brachytherapy in Cervical Cancer: A Randomised Study. Part II.
abstract: OBJECTIVE
  To compare the inter-fraction dose variation for bladder and rectum using a bladder-rectum spacer balloon (BRSB) versus vaginal gauze packing (VGP) in patients treated with high dose rate intracavitary brachytherapy for carcinoma cervix.
  
  
  METHODS
  After the completion of external radiotherapy, 80 patients were randomised to receive intracavitary brachytherapy using either the BRSB or VGP. The procedure was carried out under general anaesthesia using tandem ovoid applicators. Computed tomography-based planning was carried out and the dose was prescribed to point A. Doses to 0.1, 1 and 2 cm(3) volumes were reported for bladder and rectum for each fraction. The absolute inter-fraction dose variation for each subvolume was compared using the independent sample t-test.
  
  
  RESULTS
  The mean bladder and rectal volumes, as well as the inter-fraction volume variation, were comparable for the BRSB and VGP. The BRSB resulted in a significant reduction in absolute dose as well as the inter-fraction variation for dose to 2 cm(3) rectum volumes (BRSB 0.80 Gy, standard deviation 0.71 Gy versus VGP 1.16 Gy, standard deviation 0.83 Gy; P = 0.04). Cumulative bladder D2cm(3) doses of more than 90 Gy3 were observed in six patients in the BRSB arm versus four patients in the VGP arm (P = 0.73). In both the arms, the rectal D2cm(3) doses did not exceed 75 Gy3.
  
  
  CONCLUSIONS
  Use of a BRSB resulted in a significant reduction in inter-fraction variation in D2cm(3) rectal dose. However, no significant difference in the inter-fraction dose variation for the other subvolumes of bladder and rectum could be shown between the BRSB and VGP. The use of a BRSB may enable rectal dose reduction and inter-fraction variation where anaesthesia is not routinely used or where there is limited physician expertise. The modification suggested in the BRSB may facilitate its additional usage.
authors.affiliation: Department of Radiotherapy, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India. Electronic address: bhavana1035@gmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Rai
authors.affiliation: Department of Radiotherapy, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: F D
authors.initials: FD
authors.lastname: Patel
authors.affiliation: Department of Radiotherapy, Tata Memorial Hospital, Mumbai, India.
authors.forename: S
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Department of Radiotherapy, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: R
authors.initials: R
authors.lastname: Kapoor
authors.affiliation: Department of Radiotherapy, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
authors.affiliation: Department of Radiotherapy, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: S
authors.initials: S
authors.lastname: Kumaravelu
authors.affiliation: Regional Cancer Centre, Thiruvananthapuram, Kerala, India.
authors.forename: P
authors.initials: P
authors.lastname: Raghukumar
authors.affiliation: HLL Life Care Limited, Thiruvananthapuram, Kerala, India.
authors.forename: A S
authors.initials: AS
authors.lastname: Aprem
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D058958:Organs at Risk / Q000528:radiation effects*; D011379:Prognosis; D011446:Prospective Studies; D011832:Radiation Injuries / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012007:Rectum / Q000528:radiation effects*; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000528:radiation effects*; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D014621:Vagina / Q000528:radiation effects*
keywords: Bladder–rectum spacer balloon; brachytherapy; cervical cancer; inter-fraction dose variation