title: Evaluation of Gafchromic® EBT3 films characteristics in therapy photon, electron and proton beams.
abstract: OBJECTIVE
  To evaluate the uncertainties and characteristics of radiochromic film-based dosimetry system using the EBT3 model Gafchromic(®) film in therapy photon, electron and proton beams.
  
  
  METHODS
  EBT3 films were read using an EPSON Expression 10000XL/PRO scanner. They were irradiated in five beams, an Elekta SL25 6 MV and 18 MV photon beam, an IBA 100 MeV 5 × 5 cm(2) proton beam delivered by pencil-beam scanning, a 60 MeV fixed proton beam and an Elekta SL25 6 MeV electron beam. Reference dosimetry was performed using a FC65-G chamber (Elekta beam), a PPC05 (IBA beam) and both Markus 1916 and PPC40 Roos ion-chambers (60 MeV proton beam). Calibration curves of the radiochromic film dosimetry system were acquired and compared within a dose range of 0.4-10 Gy. An uncertainty budget was estimated on films irradiated by Elekta SL25 by measuring intra-film and inter-film reproducibility and uniformity; scanner uniformity and reproducibility; room light and film reading delay influences.
  
  
  RESULTS
  The global uncertainty on acquired optical densities was within 0.55% and could be reduced to 0.1% by placing films consistently at the center of the scanner. For all beam types, the calibration curves are within uncertainties of measured dose and optical densities. The total uncertainties on calibration curve due to film reading and fitting were within 1.5% for photon and proton beams. For electrons, the uncertainty was within 2% for dose superior to 0.8 Gy.
  
  
  CONCLUSIONS
  The low combined uncertainty observed and low beam and energy-dependence make EBT3 suitable for dosimetry in various applications.
authors.affiliation: Center of Molecular Imaging, Radiotherapy and Oncology, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Avenue Hippocrate 54, 1200 Brussels, Belgium; ICTEAM Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium. Electronic address: jefferson.sorriaux@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Sorriaux
authors.forename: A
authors.initials: A
authors.lastname: Kacperek
authors.forename: S
authors.initials: S
authors.lastname: Rossomme
authors.forename: J A
authors.initials: JA
authors.lastname: Lee
authors.forename: D
authors.initials: D
authors.lastname: Bertrand
authors.forename: S
authors.initials: S
authors.lastname: Vynckier
authors.forename: E
authors.initials: E
authors.lastname: Sterpin
mesh_terms: D002138:Calibration; D003116:Color; D004583:Electrons / Q000627:therapeutic use*; D005373:Film Dosimetry / Q000379:methods*; D017785:Photons / Q000627:therapeutic use*; D061766:Proton Therapy; D013223:Statistics as Topic; D035501:Uncertainty
keywords: Dosimetry; EBT3; Proton therapy