title: Evaluation of an electronic portal imaging device for transit dosimetry.
abstract: The possibility of using a commercially available electronic portal imaging device for transit dosimetry was investigated. The detection unit of the device comprises a metal plate/fluorescence screen and a camera. Basic parameters of this system were investigated: stability, detector uniformity, dose-response curve, field-size dependence and phantom-thickness dependence. It was found that in terms of relative dosimetry, portal images corrected for detector non-uniformity are in good agreement (within 5%) with transit dose distributions measured by film dosimetry. For dose determination, it was found that the use of the device is hampered by an important field-size dependence and phantom-thickness dependence. Both correction factors should be applied if the device is to be used for this purpose.
authors.affiliation: Department of Oncology, University Hospital Leuven, Belgium.
authors.forename: X
authors.initials: X
authors.lastname: He
authors.forename: A
authors.initials: A
authors.lastname: Van Esch
authors.forename: R
authors.initials: R
authors.lastname: Reymen
authors.forename: D
authors.initials: D
authors.lastname: Huyskens
mesh_terms: D015502:Absorptiometry, Photon; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D011786:Quality Control; D011878:Radiotherapy / Q000295:instrumentation* / Q000592:standards; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012680:Sensitivity and Specificity; D014962:X-Ray Film