Simulation of physical processes with Monte Carlo methods in the keV and MeV energy range

在 keV 和 MeV 能量范围内使用蒙特卡罗方法模拟物理过程

• 批准号: RGPIN-2021-03102
• 负责人: Bouchard, Hugo
• 金额: $ 2.48万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742380
• 关键词: Simulation; physical; processes; Monte; Carlo

The technological developments of modern medicine foster the need for detailed understanding of the physical processes involved. Physical models are the basis of research in medical physics and enable the development of fundamental methodology for the optimal use of novel technologies in radiotherapy and radiology. In radiotherapy, radiation beams are used to ionize the cellular environment and cause biological damage to eradicate tumors. Particles of interest composing therapeutic beams produce localized cascades of secondary particles, and their detailed transport in heterogeneous media needs to be simulated with Monte Carlo methods to predict the energy deposition in patients and standard environments to support personalized radiotherapy. In X-ray computed tomography (CT), patient geometries are investigated for the diagnosis of anomalies and for therapeutic interventions. Emerging applications of spectral CT involve the resolution of photon energy at the detector level which opens the way to a variety of advanced quantitative medical applications. To support this development, Monte Carlo methods are used extensively for their ability to simulate photon transport in the keV energy range, including the production of scatter and the simulation of radiation detector response converting X-rays into electric signal. Another challenging application in which Monte Carlo simulation is essential is MRI-guided radiotherapy. The promising integration of magnetic resonance imaging (MRI) to radiotherapy linacs adapt dose delivery to the target motion and other potential anatomical changes in real time. But MRI involves an external magnetic field that is strong enough to distort localized particle cascades produced by radiotherapy beams. Both radiation dose distributions and radiation detector response require the use of Monte Carlo methods to achieve accurate radiation dosimetry of MRI-guided radiotherapy beams. The main purpose of this research program is to explore various applications of Monte Carlo particle transport simulation that are relevant to modern medicine, in particular to radiotherapy and imaging. Technologies in radiotherapy and medical imaging are continuously evolving from which arises new challenges requiring careful understanding of the governing physical processes. The proposed research program will explore both practical and fundamental research in radiotherapy and medical imaging with Monte Carlo particle transport simulation. The impact of this research will contribute towards improved understanding of small and dynamic photon beams dosimetry, non-equilibrium MRI-guided radiation dosimetry, and emerging applications of spectral computed tomography.

现代医学的技术发展促进了对所涉及的物理过程的详细理解的需要。物理模型是医学物理学研究的基础，能够为放射治疗和放射学中新技术的最佳使用开发基本方法。在放射疗法中，辐射束用于破坏细胞环境并引起生物损伤以根除肿瘤。感兴趣的粒子组成的治疗光束产生局部级联的二次粒子，其在异质介质中的详细传输需要用蒙特卡罗方法来模拟，以预测在患者和标准环境中的能量沉积，以支持个性化的放射治疗。在X射线计算机断层扫描（CT）中，研究患者的几何形状以诊断异常和进行治疗干预。光谱CT的新兴应用涉及探测器水平的光子能量分辨率，这为各种先进的定量医学应用开辟了道路。为了支持这一发展，蒙特卡罗方法被广泛使用，因为它们能够模拟keV能量范围内的光子传输，包括散射的产生和将X射线转换为电信号的辐射探测器响应的模拟。另一个具有挑战性的应用，其中蒙特卡罗模拟是必不可少的是MRI引导的放射治疗。磁共振成像（MRI）与放射治疗直线加速器的有前途的集成使剂量递送真实的实时地适应靶运动和其他潜在的解剖学变化。但是MRI涉及到一个足够强的外部磁场，足以扭曲放射治疗束产生的局部粒子级联。辐射剂量分布和辐射探测器响应都需要使用蒙特卡罗方法来实现MRI引导的放射治疗射束的准确辐射剂量测定。 该研究计划的主要目的是探索与现代医学相关的蒙特卡罗粒子输运模拟的各种应用，特别是放射治疗和成像。放射治疗和医学成像技术不断发展，由此产生了新的挑战，需要仔细了解支配物理过程。拟议的研究计划将探索放射治疗和医学成像与蒙特卡罗粒子输运模拟的实践和基础研究。这项研究的影响将有助于提高对小的和动态的光子束剂量测定，非平衡MRI引导的辐射剂量测定，以及光谱计算机断层扫描的新兴应用的理解。