title: Dose distribution verification for GYN brachytherapy using EBT Gafchromic film and TG-43 calculation.
abstract: OBJECTIVE
  Verification of dose distributions for gynecological (GYN) brachytherapy implants using EBT Gafchromic film.
  
  
  BACKGROUND
  One major challenge in brachytherapy is to verify the accuracy of dose distributions calculated by a treatment planning system.
  
  
  METHODS
  A new phantom was designed and fabricated using 90 slabs of 18 cm × 16 cm × 0.2 cm Perspex to accommodate a tandem and Ovoid assembly, which is normally used for GYN brachytherapy treatment. This phantom design allows the use of EBT Gafchromic films for dosimetric verification of GYN implants with a cobalt-60 HDR system or a LDR Cs-137 system. Gafchromic films were exposed using a plan that was designed to deliver 1.5 Gy of dose to 0.5 cm distance from the lateral surface of ovoids from a pair of ovoid assembly that was used for treatment vaginal cuff. For a quantitative analysis of the results for both LDR and HDR systems, the measured dose values at several points of interests were compared with the calculated data from a commercially available treatment planning system. This planning system was utilizing the TG-43 formalism and parameters for calculation of dose distributions around a brachytherapy implant.
  
  
  RESULTS
  The results of these investigations indicated that the differences between the calculated and measured data at different points were ranging from 2.4% to 3.8% for the LDR Cs-137 and HDR Co-60 systems, respectively.
  
  
  CONCLUSIONS
  The EBT Gafchromic films combined with the newly designed phantom could be utilized for verification of the dose distributions around different GYN implants treated with either LDR or HDR brachytherapy procedures.
authors.affiliation: Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Gholami
authors.affiliation: Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Mirzaei
authors.affiliation: Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Jabbary Arfaee
authors.affiliation: Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Jaberi
authors.affiliation: Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hassan Ali
authors.initials: HA
authors.lastname: Nedaie
authors.affiliation: Department of Medical Physics, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Seied
authors.initials: S
authors.lastname: Rabi Mahdavi
authors.affiliation: Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Eftekhar
authors.initials: E
authors.lastname: Rajab Bolookat
authors.affiliation: Comprehensive Cancer Centers of Nevada, Las Vegas, NV, United States.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Meigooni
keywords: Film dosimetry; GZP6 HDR system; QA brachytherapy phantom; Selectron LDR system; TG-43