CALCULATION OF THE RADIOLOGICAL DEPTH
CALCULATION OF THE RADIOLOGICAL DEPTH
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DOI：
10.1118/1.595739
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发表时间：
1985-01-01
期刊：
影响因子：
3.8
通讯作者：
SIDDON, RL
中科院分区：
文献类型：
--
作者：
SIDDON, RL
辐射深度的概念是计算非均匀介质中辐射剂量的所有算法的核心。对于由不均匀区域组成的离散非均匀介质，辐射深度通常表示为分段长度与与分段对应的区域的非均匀密度的乘积之和。这篇文章说明了通常的公式是低效的，因为它需要解决每个线段对应的区域的拓扑问题。对于只涉及三个非均质性区域的简单非均质性问题，发现拓扑问题至少占计算辐射深度所需时间的85%。本文指出，将辐射深度表示为区域上的总和，而不是分段上的总和，可以完全避免这个拓扑问题。
The concept of the radiological depth is central to all algorithms which calculate radiation dose in a heterogeneous medium. For a discrete heterogeneous medium, consisting of regions of inhomogeneity, the radiological depth is usually presented as the sum over segments of the product of the segment length and the inhomogeneity density of the region corresponding to the segment. This paper illustrates that the usual formulation is inefficient because it requires the solution of the topological problem of which region corresponds to each segment. For simple heterogeneity problems involving just three regions of inhomogeneity, it is found that the topological problem constitutes at least 85% of the time required to calculate the radiological depth. It is shown in this paper that formulating the radiological depth as a sum over regions rather than as a sum over segments allows one to avoid this topological problem entirely.