A 3D photon superposition/convolution algorithm and its foundation on results of Monte Carlo calculations
A 3D photon superposition/convolution algorithm and its foundation on results of Monte Carlo calculations
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DOI：
10.1088/0031-9155/50/8/010
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发表时间：
2005-04-21
影响因子：
3.5
通讯作者：
Kaissl, W
中科院分区：
文献类型：
--
作者：
Ulmer, W;Pyyry, J;Kaissl, W
基于先前关于三重高斯分析笔形束模型和使用蒙特卡罗代码 GEANT-Fluka、版本 95、98、2002 和 BEAMnrc/EGSnrc 的蒙特卡罗计算的出版物，提出了光子束（6 MV、18 MV）的三维（3D）叠加/卷积算法。 CT 图像的电子密度信息考虑了组织异质性。临床光束由发散笔形光束的叠加组成。使用板几何形状作为模型模型来通过测量来测试计算结果。一个重要的结果是在密度不连续范围内存在进一步的剂量累积和累积效应。这些影响随着场大小的增加而增加
Based on previous publications on a triple Gaussian analytical pencil beam model and on Monte Carlo calculations using Monte Carlo codes GEANT-Fluka, versions 95, 98, 2002, and BEAMnrc/EGSnrc, a three-dimensional (3D) superposition/convolution algorithm for photon beams (6 MV, 18 MV) is presented. Tissue heterogeneity is taken into account by electron density information of CT images. A clinical beam consists of a superposition of divergent pencil beams. A slab-geometry was used as a phantom model to test computed results by measurements. An essential result is the existence of further dose build-up and build-down effects in the domain of density discontinuities. These effects have increasing magnitude for field sizes