Time-resolved diode dosimetry calibration through Monte Carlo modeling forin vivopassive scattered proton therapy range verification
| Autor: | A. Toltz, Harald Paganetti, Hsiao-Ming Lu, Jan Schuemann, Michaela A.U. Hoesl, Jan Seuntjens |
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| Rok vydání: | 2017 |
| Předmět: |
Monte Carlo method
TOPAS Radiation Dosage 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics Path length Proton Therapy Calibration Radiation Oncology Physics Humans Scattering Radiation Dosimetry Radiology Nuclear Medicine and imaging Instrumentation Proton therapy Diode Physics Radiation business.industry Radiotherapy Planning Computer-Assisted Detector Uncertainty Reproducibility of Results Water radiation dosimetry 030220 oncology & carcinogenesis 87.53.Qc Physics::Accelerator Physics business Monte Carlo Method Plastics Beam (structure) |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| Popis: | Purpose Our group previously introduced an in vivo proton range verification methodology in which a silicon diode array system is used to correlate the dose rate profile per range modulation wheel cycle of the detector signal to the water-equivalent path length (WEPL) for passively scattered proton beam delivery. The implementation of this system requires a set of calibration data to establish a beam-specific response to WEPL fit for the selected ‘scout’ beam (a 1 cm overshoot of the predicted detector depth with a dose of 4 cGy) in water-equivalent plastic. This necessitates a separate set of measurements for every ‘scout’ beam that may be appropriate to the clinical case. The current study demonstrates the use of Monte Carlo simulations for calibration of the time-resolved diode dosimetry technique. Methods Measurements for three ‘scout’ beams were compared against simulated detector response with Monte Carlo methods using the Tool for Particle Simulation (TOPAS). The ‘scout’ beams were then applied in the simulation environment to simulated water-equivalent plastic, a CT of water-equivalent plastic, and a patient CT data set to assess uncertainty. Results Simulated detector response in water-equivalent plastic was validated against measurements for ‘scout’ spread out Bragg peaks of range 10 cm, 15 cm, and 21 cm (168 MeV, 177 MeV, and 210 MeV) to within 3.4 mm for all beams, and to within 1 mm in the region where the detector is expected to lie. Conclusion Feasibility has been shown for performing the calibration of the detector response for three ‘scout’ beams through simulation for the time-resolved diode dosimetry technique in passive scattered proton delivery. |
| Databáze: | OpenAIRE |
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