A Monte Carlo study of lung counting efficiency for female workers of different breast sizes using deformable phantoms.
A Monte Carlo study of lung counting efficiency for female workers of different breast sizes using deformable phantoms.
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DOI：
10.1088/0031-9155/53/19/017
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发表时间：
2008-10-07
影响因子：
3.5
通讯作者：
Xu XG
中科院分区：
文献类型：
--
作者：
Hegenbart L;Na YH;Zhang JY;Urban M;Xu XG
目前还没有实体模型可用于校准代表不同乳房大小的女性的体内计数设备，因为这样的模型制造起来困难，耗时且昂贵。在这项工作中，探讨了一种可行的替代方案，包括计算幻影。开发了一系列具有不同乳房大小的新女性体素幻象，并将其移植到蒙特卡罗辐射传输代码中，用于进行虚拟肺计数效率校准。这些幻影是基于RPI成年女性幻影，一种边界表示（BREP）模型。它们是用新颖的变形技术创建的，然后为蒙特卡罗模拟进行体素化。根据文胸行业标准，选出了从AA到G的8款罩杯。用这些模型进行了肺计数系统的蒙特卡罗模拟，以研究乳房大小对肺计数效率的影响，这是确定沉积在肺部的放射性核素的活性并因此估计对工作人员产生的剂量所必需的。研究人员考虑了涉及三种不同放射性核素的污染情景，即Am-241、Cs-137和Co-60。结果表明，随着乳房尺寸的增大，探测器效率显著降低，特别是对于低能量光子发射的放射性核素。当将罩杯大小为AA的模型与罩杯大小为G的模型进行比较时，可以观察到高达50%的差异。每种放射性核素的检测器效率可以用乳房总质量（二阶多项式）或罩杯大小（功率）的曲线拟合来近似。
There are currently no physical phantoms available for calibrating in vivo counting devices that represent women with different breast sizes because such phantoms are difficult, time consuming and expensive to fabricate. In this work, a feasible alternative involving computational phantoms was explored. A series of new female voxel phantoms with different breast sizes were developed and ported into a Monte Carlo radiation transport code for performing virtual lung counting efficiency calibrations. The phantoms are based on the RPI adult female phantom, a boundary representation (BREP) model. They were created with novel deformation techniques and then voxelized for the Monte Carlo simulations. Eight models have been selected with cup sizes ranging from AA to G according to brassiere industry standards. Monte Carlo simulations of a lung counting system were performed with these phantoms to study the effect of breast size on lung counting efficiencies, which are needed to determine the activity of a radionuclide deposited in the lung and hence to estimate the resulting dose to the worker. Contamination scenarios involving three different radionuclides, namely Am-241, Cs-137 and Co-60, were considered. The results show that detector efficiencies considerably decrease with increasing breast size, especially for low energy photon emitting radionuclides. When the counting efficiencies of models with cup size AA were compared to those with cup size G, a difference of up to 50% was observed. The detector efficiencies for each radionuclide can be approximated by curve fitting in the total breast mass (polynomial of second order) or the cup size (power).
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DOI：
10.1109/tvcg.2003.1196006
发表时间：
2003-04-01
影响因子：
5.2
作者：
Nooruddin, FS;Turk, G
通讯作者：
Turk, G
影响因子：
2.2
作者：
BERGER, CD;LANE, BH
通讯作者：
LANE, BH
影响因子：
1
作者：
Kramer, GH;Burns, LC
通讯作者：
Burns, LC
影响因子：
2.2
作者：
Kramer, GH;Capello, K
通讯作者：
Capello, K
影响因子：
5.5
作者：
Armato, SG;Giger, ML;MacMahon, H
通讯作者：
MacMahon, H