title: CT-based interstitial brachytherapy in advanced gynecologic malignancies: outcomes from a single institution experience.
abstract: OBJECTIVE
  To evaluate the clinical outcomes of women receiving a "short" course of high-dose-rate gynecologic interstitial brachytherapy (HDR-ISBT) boost with CT-based 3D planning.
  
  
  METHODS
  Forty-seven women with no prior radiation received HDR-ISBT from August 2004 to February 2012. The mean external beam radiotherapy dose was 45 Gy. A mean HDR-ISBT boost dose of 18.4 Gy was delivered over 2-4 fractions. Dose volume histograms (DVHs) were computed for organs at risk and clinical target volume.
  
  
  RESULTS
  With a median followup of 34.8 months, the 3-year local control rate was 68%. Sixteen patients were identified to have tumor recurrence (including eight local). The median time to any recurrence was 26.8 months. Relapse-free survival and overall survival at 3 years was 65% and 73%, respectively. Ten patients experienced Grade 3 late toxicity, mainly vaginal (5) and proctitis (3). The mean prescription volume (V100) was 85 cc and the mean D90 to CTV was 98%. The mean cumulative dose to tumor was 69.9 Gy (equivalent dose in 2 Gy). The mean cumulative equivalent dose in 2 Gy to D2cc of bladder and rectum was 60.9 Gy and 63.0 Gy, respectively.
  
  
  CONCLUSIONS
  A "short" course HDR-ISBT is effective, safe, and convenient with acceptable local control and toxicity. Higher dose per fraction is similar to an external beam radiotherapy stereotactic boost with the inherent advantages of brachytherapy. A shorter overall time for HDR-ISBT means less time that patients are immobilized and in hospital, making it less resource intensive than a longer course.
authors.affiliation: Department of Radiation Oncology, London Health Sciences Centre, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada. Electronic address: David.DSouza@lhsc.on.ca.
authors.forename: David
authors.initials: D
authors.lastname: D'Souza
authors.affiliation: Department of Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada.
authors.forename: Ericka
authors.initials: E
authors.lastname: Wiebe
authors.affiliation: Department of Radiation Oncology, Nova Scotia Cancer Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Nikhilesh
authors.initials: N
authors.lastname: Patil
authors.affiliation: Department of Oncology, Western University, London, Ontario, Canada; Department of Obstetrics and Gynecology, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Akira
authors.initials: A
authors.lastname: Sugimoto
authors.affiliation: Department of Oncology, Western University, London, Ontario, Canada; Department of Obstetrics and Gynecology, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Prefontaine
authors.affiliation: Department of Medical Biophysics, Western University, London, Ontario, Canada.
authors.forename: Simran
authors.initials: S
authors.lastname: Aulakh
authors.affiliation: Clinical Research Unit, London Regional Cancer Program, London, Ontario, Canada.
authors.forename: Frances
authors.initials: F
authors.lastname: Whiston
authors.affiliation: Clinical Research Unit, London Regional Cancer Program, London, Ontario, Canada.
authors.forename: Larry
authors.initials: L
authors.lastname: Stitt
authors.affiliation: Department of Oncology, Western University, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; Department of Medical Physics, London Regional Cancer Program, London, Ontario, Canada.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Surry
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D005833:Genital Neoplasms, Female / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage
keywords: Gynecologic; Interstitial brachytherapy