title: Energy dependence of radiochromic dosimetry films for use in radiotherapy verification.
abstract: OBJECTIVE
  The purpose of the study was to examine the energy dependence of Gafchromic EBT radiochromic dosimetry films, in order to assess their potential use in intensity-modulated radiotherapy (IMRT) verifications.
  
  
  METHODS
  The film samples were irradiated with doses from 0.1 to 12 Gy using photon beams from the energy range 1.25 MeV to 25 MV and the film response was measured using a flat-bed scanner. The samples were scanned and the film responses for different beam energies were compared.
  
  
  RESULTS
  A high uncertainty in readout of the film response was observed for samples irradiated with doses lower than 1 Gy. The relative difference exceeds 20% for doses lower than 1 Gy while for doses over 1 Gy the measured film response differs by less than 5% for the whole examined energy range. The achieved uncertainty of the experimental procedure does not reveal any energy dependence of Gafchromic EBT film response in the investigated energy range.
  
  
  CONCLUSIONS
  Gafchromic EBT film does not show any energy dependence in the conditions typical for IMRT but the doses measured for pre-treatment plan verifications should exceed 1 Gy.
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Chełmiński
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bulski
authors.affiliation: Division of Medical Radiation Physics, University of Vienna Medical School, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Georg
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Bodzak
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Maniakowski
authors.affiliation: Department of Medical Physics, Lower Silesian Oncology Centre, pl. Hirszfelda 12, 53-413 Wrocław, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Oborska
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Rostkowska
authors.affiliation: Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kania
keywords: Film dosimetry; Quality assurance; Radiochromic films