Output factor comparison of Monte Carlo and measurement for Varian TrueBeam 6 MV and 10 MV flattening filter-free stereotactic radiosurgery system
| Autor: | Ying Zhuge, Jason Y. Cheng, Holly Ning, B. Arora, Robert W. Miller |
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| Rok vydání: | 2015 |
| Předmět: |
Photon
medicine.medical_treatment Monte Carlo method stereotactic radiosurgery Dose profile Radiosurgery small field dosimetry Flattening 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics medicine Dosimetry Humans Radiation Oncology Physics Radiology Nuclear Medicine and imaging Computer Simulation Radiometry Instrumentation Monte Carlo Physics Photons output factors Radiation business.industry Phantoms Imaging Radiotherapy Planning Computer-Assisted Detector Truebeam Water 030220 oncology & carcinogenesis business Monte Carlo Method Algorithms |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| Popis: | The dose measurements of the small field sizes, such as conical collimators used in stereotactic radiosurgery (SRS), are a significant challenge due to many factors including source occlusion, detector size limitation, and lack of lateral electronic equilibrium. One useful tool in dealing with the small field effect is Monte Carlo (MC) simulation. In this study, we report a comparison of Monte Carlo simulations and measurements of output factors for the Varian SRS system with conical collimators for energies of 6 MV flattening filter‐free (6 MV) and 10 MV flattening filter‐free (10 MV) on the TrueBeam accelerator. Monte Carlo simulations of Varian's SRS system for 6 MV and 10 MV photon energies with cones sizes of 17.5 mm, 15.0 mm, 12.5 mm, 10.0 mm, 7.5 mm, 5.0 mm, and 4.0 mm were performed using EGSnrc (release V4 2.4.0) codes. Varian's version‐2 phase‐space files for 6 MV and 10 MV of TrueBeam accelerator were utilized in the Monte Carlo simulations. Two small diode detectors Edge (Sun Nuclear) and Small Field Detector (SFD) (IBA Dosimetry) were applied to measure the output factors. Significant errors may result if detector correction factors are not applied to small field dosimetric measurements. Although it lacked the machine‐specific kQclin,Qmsrfclin,fmsr correction factors for diode detectors in this study, correction factors were applied utilizing published studies conducted under similar conditions. For cone diameters greater than or equal to 12.5 mm, the differences between output factors for the Edge detector, SFD detector, and MC simulations are within 3.0% for both energies. For cone diameters below 12.5 mm, output factors differences exhibit greater variations. PACS number(s): 87.55.k, 87.55.Qr |
| Databáze: | OpenAIRE |
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