Clinical validation of an in-house EPID dosimetry system for IMRT QA at the Prince of Wales Hospital

7th International Conference on 3D Radiation Dosimetry

Tyler, M.^1,2 ; Vial, P.^3,4 ; Metcalfe, P.^2 ; Downes, S.^1

Department of Medical Physics, Prince of Wales Hospital, Randwick, NSW, Australia^1

Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia^2

Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centres, NSW, Australia^3

Institute of Medical Physics, School of Physics, University of Sydney, NSW, Australia^4

关键词: Clinical validations;    Electronic portal imaging devices;    Field generations;    Intensity-modulated radiation therapy;    Planning systems;    Siemens medical solutions;    SIMPLE method;    Step-and-shoot;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012043/pdf
DOI  :  10.1088/1742-6596/444/1/012043

来源: IOP

【 摘 要 】

In this study a simple method using standard flood-field corrected Electronic Portal Imaging Device (EPID) images for routine Intensity Modulated Radiation Therapy (IMRT) Quality Assurance (QA) was investigated. The EPID QA system was designed and tested on a Siemens Oncor Impression linear accelerator with an OptiVue 1000ST EPID panel (Siemens Medical Solutions USA, Inc, USA) and an Elekta Axesse linear accelerator with an iViewGT EPID (Elekta AB, Sweden) for 6 and 10 MV IMRT fields with Step-and-Shoot and dynamic-MLC delivery. Two different planning systems were used for patient IMRT field generation for comparison with the measured EPID fluences. All measured IMRT plans had >95% agreement to the planning fluences (using 3 cGy / 3 mm Gamma Criteria) and were comparable to the pass-rates calculated using a 2-D diode array dosimeter.