Monte Carlo modeling in CT-based geometries: dosimetry for biological modeling experiments with particle beam radiation.
Monte Carlo modeling in CT-based geometries: dosimetry for biological modeling experiments with particle beam radiation.
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基于 CT 的几何形状中的蒙特卡罗建模：粒子束辐射生物建模实验的剂量测定。
DOI：
10.1093/jrr/rrt118
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发表时间：
2014
影响因子：
2
通讯作者：
Cengel,KeithA
中科院分区：
文献类型：
--
作者：
Diffenderfer,EricS;Dolney,Derek;Schaettler,Maximilian;Sanzari,JenineK;McDonough,James;Cengel,KeithA
空间辐射环境增加了暴露于电离辐射的危险，特别是在太阳粒子事件(SPE)期间。这些事件主要由产生高度不均匀剂量分布的低能质子组成。由于这种固有的剂量异质性，旨在调查SPE辐射的放射生物学效应的实验在评估和解释敏感器官的剂量方面存在困难。为了应对这一挑战，我们使用Geant4蒙特卡罗模拟框架开发了剂量测量软件，该软件使用计算机断层扫描(CT)图像并提供包含所有相关物理相互作用过程的辐射传输模拟。我们发现，这种模拟可以准确地预测模体中的测量数据，并可以应用于使用带电粒子(电子和质子)束暴露的动物模型进行放射生物学实验中的剂量模型。这项研究清楚地证明了蒙特卡罗辐射传输方法在两个相互关联的应用中的价值：(I)在类SPE辐射的动物实验中确定总体剂量分布和特定器官系统的剂量水平，以及(Ii)解释实验变量(例如，长时间暴露期间的动物运动)中的随机和系统变化对剂量分布和由此产生的类SPE辐射的生物效应的影响。在这项研究中开发和验证的软件是一个至关重要的新工具，它允许集成计算和生物模拟来评估暴露于非均匀SPE类辐射剂量分布的生物学结果，并可能应用于其他环境和治疗性暴露模拟。
The space radiation environment imposes increased dangers of exposure to ionizing radiation, particularly during a solar particle event (SPE). These events consist primarily of low energy protons that produce a highly inhomogeneous dose distribution. Due to this inherent dose heterogeneity, experiments designed to investigate the radiobiological effects of SPE radiation present difficulties in evaluating and interpreting dose to sensitive organs. To address this challenge, we used the Geant4 Monte Carlo simulation framework to develop dosimetry software that uses computed tomography (CT) images and provides radiation transport simulations incorporating all relevant physical interaction processes. We found that this simulation accurately predicts measured data in phantoms and can be applied to model dose in radiobiological experiments with animal models exposed to charged particle (electron and proton) beams. This study clearly demonstrates the value of Monte Carlo radiation transport methods for two critically interrelated uses: (i) determining the overall dose distribution and dose levels to specific organ systems for animal experiments with SPE-like radiation, and (ii) interpreting the effect of random and systematic variations in experimental variables (e.g. animal movement during long exposures) on the dose distributions and consequent biological effects from SPE-like radiation exposure. The software developed and validated in this study represents a critically important new tool that allows integration of computational and biological modeling for evaluating the biological outcomes of exposures to inhomogeneous SPE-like radiation dose distributions, and has potential applications for other environmental and therapeutic exposure simulations.