Comparison of RTP dose distributions in heterogeneous phantoms with the BEAM Monte Carlo simulation system.
Comparison of RTP dose distributions in heterogeneous phantoms with the BEAM Monte Carlo simulation system.
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DOI：
10.1120/jacmp.v2i1.2623
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发表时间：
2001
影响因子：
2.1
通讯作者：
Ma CM
中科院分区：
文献类型：
--
作者：
Miften M;Wiesmeyer M;Kapur A;Ma CM
治疗方案的评估通常基于检查放射治疗计划（RTP）系统剂量在靶区和周围正常结构中的分布。为了研究组织不均匀性对光子剂量分布的影响，我们比较了基于测量的克拉克森和基于模型的多网格叠加（MGS）算法的FOCUS RTP系统剂量分布与来自光束蒙特卡罗编码系统的剂量分布。虚幻的不均匀性模拟了相关的临床治疗部位，包括肺板、肺-骨板、骨-肺板、纵隔和肿瘤几何形状。在肺密度为0.20和，骨密度为0.20和15 MV光子束的情况下进行基准比较。基准对比结果表明，MGS模型与光束剂量的匹配度均优于3%或3mm，在所有幻影中MGS模型都比Clarkson模型更精确。与克拉克森模型不同，MGS模型预测了与高能束相关的组织界面附近剂量的积聚和积聚以及肺中半暗带的展宽。克拉克森模型比束流最大高估了肺内剂量10%。剂量比较建议关闭Clarkson模型中用于肺部治疗的有效路径长度非均匀性校正。PACS数值：87.53。- j, 87.53.Bn
Therapeutic treatment plan evaluation is often based on examining the radiotherapy treatment planning (RTP) system dose distributions in the target and surrounding normal structures. To study the effects of tissue inhomogeneities on photon dose distributions, we compared FOCUS RTP system dose distributions from the measurement‐based Clarkson and model‐based MultiGrid Superposition (MGS) algorithms with those from the beam Monte Carlo code system in a set of heterogeneous phantoms. The phantom inhomogeneities mimic relevant clinical treatment sites, which include lung slab, lung‐bone slab, bone‐lung slab, mediastinum, and tumor geometries. The benchmark comparisons were performed in lung densities of 0.20 and , and a bone density of for and and 15‐MV photon beams. Benchmark comparison results show that the MGS model and beam doses match better than 3% or 3 mm, and the MGS model is more accurate than the Clarkson model in all phantoms. The MGS model, unlike the Clarkson model, predicts the build‐down and build‐up of dose near tissue interfaces and penumbra broadening in lung associated with high energy beams. The Clarkson model overestimates the dose in lung by a maximum of 10% compared to beam. Dose comparisons suggest turning‐off the effective path length inhomogeneity correction in the Clarkson model for lung treatments. PACS number(s): 87.53.–j, 87.53.Bn