title: [A practical procedure to improve the accuracy of radiochromic film dosimetry: a integration with a correction method of uniformity correction and a red/blue correction method].
abstract: It has been reported that the light scattering could worsen the accuracy of dose distribution measurement using a radiochromic film. The purpose of this study was to investigate the accuracy of two different films, EDR2 and EBT2, as film dosimetry tools. The effectiveness of a correction method for the non-uniformity caused from EBT2 film and the light scattering was also evaluated. In addition the efficacy of this correction method integrated with the red/blue correction method was assessed. EDR2 and EBT2 films were read using a flatbed charge-coupled device scanner (EPSON 10000G). Dose differences on the axis perpendicular to the scanner lamp movement axis were within 1% with EDR2, but exceeded 3% (Maximum: +8%) with EBT2. The non-uniformity correction method, after a single film exposure, was applied to the readout of the films. A corrected dose distribution data was subsequently created. The correction method showed more than 10%-better pass ratios in dose difference evaluation than when the correction method was not applied. The red/blue correction method resulted in 5%-improvement compared with the standard procedure that employed red color only. The correction method with EBT2 proved to be able to rapidly correct non-uniformity, and has potential for routine clinical IMRT dose verification if the accuracy of EBT2 is required to be similar to that of EDR2. The use of red/blue correction method may improve the accuracy, but we recommend we should use the red/blue correction method carefully and understand the characteristics of EBT2 for red color only and the red/blue correction method.
authors.affiliation: Department of Radiation Oncology, The Cancer Institute Hospital of JFCR.
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Uehara
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Tachibana
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ito
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yoshino
authors.forename: Fumiyasu
authors.initials: F
authors.lastname: Matsubayashi
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Sato
mesh_terms: D005373:Film Dosimetry / Q000295:instrumentation / Q000379:methods*; D011785:Quality Assurance, Health Care; D011829:Radiation Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods