A GPU-based Monte Carlo framework for IMRT QA using EPID transit dosimetry

Fuente: arXiv
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Main Authors: Gao, Ning, Li, Didi, Liu, Na, Chang, Yankui, Ren, Qiang, Pei, Xi, Wang, Zhi, Xu, Xie George
Format: Preprint
Published: 2025
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author Gao, Ning
Li, Didi
Liu, Na
Chang, Yankui
Ren, Qiang
Pei, Xi
Wang, Zhi
Xu, Xie George
author_facet Gao, Ning
Li, Didi
Liu, Na
Chang, Yankui
Ren, Qiang
Pei, Xi
Wang, Zhi
Xu, Xie George
contents Purpose: We presented a GPU-based MC framework, ARCHER-EPID, specifically designed for EPID transit dosimetry, with improving accuracy and efficiency. Methods: A comprehensive MC framework was developed to perform full radiation transport simulations through three distinct zones: a detailed linear accelerator head model, a CT-based patient/phantom geometry, and a realistic, multi-layered EPID model. To convert the simulated absorbed dose to a realistic detector signal, a dose-response correction model was implemented. The framework was validated by comparing simulations against experimental measurements for 25 IMRT fields delivered to both a solid water phantom and a anthropomorphic phantom. Agreement was quantified using Gamma analysis. Results: The GPU-accelerated ARCHER-EPID framework can complete the simulation for a complex IMRT field in about 90 seconds. A 2D correction factor lookup table is generated by parameterizing radiological thickness and effective field size to account for the EPID's energy-dependent response. The data revealed that for small fields, beam hardening is the dominant effect, while for large fields, the contribution from patient-generated scatter overwhelms this effect. The average 2D gamma passing rates (3%/3 mm criteria) between simulation and measurements are 98.43% for the solid water phantom and 97.86% for the anthropomorphic phantom, respectively. Visual comparison of the images and dose profiles between simulation and measurements show a high degree of agreement. Conclusions: We have successfully developed and validated a GPU-based MC framework that provides gold-standard accuracy for EPID transit dosimetry in radiotherapy. The results demonstrate that our proposed method has potential for routine application in PSQA.
format Preprint
id arxiv_https___arxiv_org_abs_2510_24154
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A GPU-based Monte Carlo framework for IMRT QA using EPID transit dosimetry
Gao, Ning
Li, Didi
Liu, Na
Chang, Yankui
Ren, Qiang
Pei, Xi
Wang, Zhi
Xu, Xie George
Medical Physics
Purpose: We presented a GPU-based MC framework, ARCHER-EPID, specifically designed for EPID transit dosimetry, with improving accuracy and efficiency. Methods: A comprehensive MC framework was developed to perform full radiation transport simulations through three distinct zones: a detailed linear accelerator head model, a CT-based patient/phantom geometry, and a realistic, multi-layered EPID model. To convert the simulated absorbed dose to a realistic detector signal, a dose-response correction model was implemented. The framework was validated by comparing simulations against experimental measurements for 25 IMRT fields delivered to both a solid water phantom and a anthropomorphic phantom. Agreement was quantified using Gamma analysis. Results: The GPU-accelerated ARCHER-EPID framework can complete the simulation for a complex IMRT field in about 90 seconds. A 2D correction factor lookup table is generated by parameterizing radiological thickness and effective field size to account for the EPID's energy-dependent response. The data revealed that for small fields, beam hardening is the dominant effect, while for large fields, the contribution from patient-generated scatter overwhelms this effect. The average 2D gamma passing rates (3%/3 mm criteria) between simulation and measurements are 98.43% for the solid water phantom and 97.86% for the anthropomorphic phantom, respectively. Visual comparison of the images and dose profiles between simulation and measurements show a high degree of agreement. Conclusions: We have successfully developed and validated a GPU-based MC framework that provides gold-standard accuracy for EPID transit dosimetry in radiotherapy. The results demonstrate that our proposed method has potential for routine application in PSQA.
title A GPU-based Monte Carlo framework for IMRT QA using EPID transit dosimetry
topic Medical Physics
url https://arxiv.org/abs/2510.24154