TY - GEN
T1 - Initial application of a geometric QA tool for integrated MV and kV imaging systems on Trilogy, Synergy, and Vero
AU - Mao, Weihua
AU - Speiser, Michael
AU - Medin, Paul
AU - Papiez, Lech
AU - Solberg, Timothy
AU - Xing, Lei
N1 - Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2009
Y1 - 2009
N2 - Introduction: Several linacs with integrated kV imaging have been developed for delivery of image-guided Stereotactic Body Radiation Therapy (SBRT). High geometric accuracy and coincidence of kilovoltage (kV) imaging systems and MV beam delivery are essential for successful image guidance. A geometric QA tool is available of evaluating and characterizing geometric accuracy of kV and MV cone beam imaging systems. Materials and Methods: This geometric QA tool has been adapted as a routine QA tool for three different types of SBRT-dedicated linacs. They are a Varian Trilogy (Varian Medical Systems, Palo Alto, California, USA), Elekta Synergy (Elekta, Stockholm, Sweden), and Brainlab Vero (Brainlab AG, Feldkirchen, Germany). Both the Trilogy and Synergy linacs are equipped with a retractable kV x-ray tube and a flat panel detector. The Vero utilizes a rotating, rigid ring structure integrating a MV x-ray head mounted on orthogonal gimbals, an electronic portal imaging device (EPID), two kV xray tubes, and fixed two flat panel detectors. Two QA phantoms were built to suit different field sizes. Projection images of a QA phantom were acquired by MV and kV imaging systems at a series of gantry angles. In-house software was used to analyze projection images and calculate eight geometric parameters for each projection. Results: Over 4,300 individual projections have been acquired and analyzed. The Trilogy was calibrated 4 times over a six month period while the Synergy and the Vero were calibrated twice and once, respectively. Quantitative geometric parameters of both MV and kV imaging systems were successfully evaluated. Isocenter consistency of the imaging systems was evaluated. Additionally, the gimbal-based x-ray source positioning of the Vero was examined. Conclusion: Geometric accuracies of both MV and integrated kV imaging systems were quantitatively evaluated by this QA tool.
AB - Introduction: Several linacs with integrated kV imaging have been developed for delivery of image-guided Stereotactic Body Radiation Therapy (SBRT). High geometric accuracy and coincidence of kilovoltage (kV) imaging systems and MV beam delivery are essential for successful image guidance. A geometric QA tool is available of evaluating and characterizing geometric accuracy of kV and MV cone beam imaging systems. Materials and Methods: This geometric QA tool has been adapted as a routine QA tool for three different types of SBRT-dedicated linacs. They are a Varian Trilogy (Varian Medical Systems, Palo Alto, California, USA), Elekta Synergy (Elekta, Stockholm, Sweden), and Brainlab Vero (Brainlab AG, Feldkirchen, Germany). Both the Trilogy and Synergy linacs are equipped with a retractable kV x-ray tube and a flat panel detector. The Vero utilizes a rotating, rigid ring structure integrating a MV x-ray head mounted on orthogonal gimbals, an electronic portal imaging device (EPID), two kV xray tubes, and fixed two flat panel detectors. Two QA phantoms were built to suit different field sizes. Projection images of a QA phantom were acquired by MV and kV imaging systems at a series of gantry angles. In-house software was used to analyze projection images and calculate eight geometric parameters for each projection. Results: Over 4,300 individual projections have been acquired and analyzed. The Trilogy was calibrated 4 times over a six month period while the Synergy and the Vero were calibrated twice and once, respectively. Quantitative geometric parameters of both MV and kV imaging systems were successfully evaluated. Isocenter consistency of the imaging systems was evaluated. Additionally, the gimbal-based x-ray source positioning of the Vero was examined. Conclusion: Geometric accuracies of both MV and integrated kV imaging systems were quantitatively evaluated by this QA tool.
KW - Geometric calibration
KW - Image guidance
KW - MV imaging
KW - QA
KW - kV imaging
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U2 - 10.1007/978-3-642-03474-9_101
DO - 10.1007/978-3-642-03474-9_101
M3 - Conference contribution
AN - SCOPUS:77950381177
SN - 9783642034725
T3 - IFMBE Proceedings
SP - 358
EP - 361
BT - World Congress on Medical Physics and Biomedical Engineering
PB - Springer Verlag
T2 - World Congress on Medical Physics and Biomedical Engineering: Radiation Oncology
Y2 - 7 September 2009 through 12 September 2009
ER -