区域蒙卡剂量计算方法中过渡层厚度的取值对计算时间和精度的影响
Influence of Transition Region’s Thickness on Calculated Time and Precision in Regional Monte Carlo Dose Calculation
本工作探索了过渡层厚度的取值对计算速度和感兴趣区域计算精度的影响。本文使用EGSnrc程序,模拟粒子在水模体中的输运状况,研究分别沿中心轴方向和垂直中心轴方向,不同的过渡层厚度对计算时间和剂量分布的影响。结果发现:在沿着中心轴的方向,减少过渡层的厚度可线性减少计算时间;在垂直中心轴方向,过渡层的厚度和计算时间之间有一个高斯衰减的关系,同时对添加了一定厚度过渡层的模体进行蒙卡计算,在感兴趣区域内的剂量精度符合临床标准。得到的结论是:在使用蒙特卡罗方法计算感兴趣区域的剂量时,可以用原始感兴趣区域加上合理的过渡层来代替全空间模体,从而在保证感兴趣区域的精度的同时,极大的减少计算时间。
he purpose of this study was to explore the influence of transition region’s thickness on calculated time and precision in regional Monte Carlo dose calculation. Monte Carlo code DOSXYZnrc in the EGSnrc system was used to simulate the transport of particles in water phantom, calculate the dose distribution in water phantom with various transition regions’ thickness along and off the central axis. The results showed that along the direction of central axis, the decrease of transition region’s thickness could reduce the calculated time linearly; off the direction of central axis, there was a Gaussian attenuation relationship between transition region’s thickness and calculated time; still had the precision of the ROI(region of interested) been acceptable in clinic when enlarged ROI with reasonable transition region’s thickness. Thereby, in Monte Carlo dose calculation method, when replaced the whole phantom with a reasonable enlarged ROI, the precision of the ROI would be good enough comparing with the result of the whole phantom, while the calculated time would become shorter greatly.
吴宜灿、兰海洋、李贵、郑华庆、宋钢、孟耀、胡碧涛
医学研究方法基础医学物理学
剂量计算蒙特卡罗方法区域蒙卡方法过渡层
dose calculationMonte Carloregional Monte Carlotransition region
吴宜灿,兰海洋,李贵,郑华庆,宋钢,孟耀,胡碧涛.区域蒙卡剂量计算方法中过渡层厚度的取值对计算时间和精度的影响[EB/OL].(2009-04-29)[2025-08-18].http://www.paper.edu.cn/releasepaper/content/200904-892.点此复制
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