A Comparison of physical and dosimetric properties of lung substitute materials
A Comparison of physical and dosimetric properties of lung substitute materials
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DOI：
10.1118/1.3694097
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发表时间：
2012-04-01
期刊：
影响因子：
3.8
通讯作者：
Huang, Ruey-Jing
中科院分区：
文献类型：
--
作者：
Chang, Kwo-Ping;Hung, Shang-Ho;Huang, Ruey-Jing
目的：由于需要准确估计受照射胸部组织内和周围的吸收剂量，因此必须使用精心选择的材料来构建体模。肺替代物更难以建立，主要是由于其物理密度低。虽然许多研究人员使用软木作为肺替代品，很少有研究数据地址软木的特性，以确定哪种类型的软木是最佳的替代肺tissue.Methods：天然软木，合成软木，橡胶软木，原子，RANDO，和参考肺材料（ICRU-44肺组织）进行了研究，以建立比较的物理性能。在确定各自的物理特性后，使用蒙特卡罗方法评估了水/肺替代物/水模型中6 MV光子束的剂量分布。结果：合成软木的物理性质（物理密度、电子密度和有效原子序数）与ICRU-44肺最接近，合成软木的CT值与30 ~ 60岁人的CT值非常接近。由于所研究肺材料的物理密度（PD）和每克电子密度（EDG）的综合特性，组合软木和RANDO体模的PDD与1 x 1 cm 2射野尺寸的ICRU-44肺的PDD最具可比性。PD和EDG主要在小射野尺寸中影响肺剂量。PD的影响是最小的，在大的领域，有一个更快的横向电子平衡。当施加大的场时，EDG主导肺材料中的PDD图案。PD和EDG的组合效应是非线性的所有字段sizes.Conclusions：组合物软木是首选的肺替代品的物理和剂量学特性的基础上。(C)2012年美国医学物理学家协会。[http：//dx.doi.org/10.1118/1.3694097]
Purpose: The need for an accurate estimate of absorbed doses within and around irradiated thorax tissues necessitates the use of carefully selected materials from which phantoms are constructed. A lung substitute is more difficult to establish mostly due to its low physical density. Although many researchers have used cork as a lung substitute, very little research data address cork's characteristics to determine which type of cork is optimal as a substitute for lung tissue.Methods: Natural cork, composition cork, rubber cork, ATOM, RANDO, and a reference lung material (ICRU-44 lung tissue) were investigated to establish comparisons of physical properties. Following the determination of the respective physical properties, the dose distributions from 6 MV photon beams in water/lung substitute/water phantoms were assessed using the Monte Carlo method. Physical and electron densities affecting the dose distributions through lung tissues in different field size conditions were investigatedResults: The physical properties (physical density, electronic density, and effective atomic number) of the composition cork are the most similar to those of the ICRU-44 lung, and the CT number of the composition cork is very similar to that of humans aged 30-60. PDD of the composition cork and the RANDO phantom are the most comparable to that of ICRU-44 lung in 1 x 1 cm2 field size due to the combined properties of physical density (PD) and electron density per gram (EDG) of the studied lung materials. PD and EDG affect the lung dose primarily in small field size. The effects of PD are minimal in large fields, having a more rapid lateral electron equilibrium. EDG dominates PDD pattern in lung material when large fields are applied. Combined effects of PD and EDG are nonlinear for all field sizes.Conclusions: The composition cork is the preferred lung substitute based on physical and dosimetric properties. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.3694097]