The use of dose coefficients (DCs) based on the reference phantoms recommended by the International Commission on Radiological Protection (ICRP) with a fixed body size may produce errors to the estimated organ/tissue doses to be used, for example, for epidemiologic studies depending on the body size of cohort members. A set of percentile-specific computational phantoms that represent 10th, 50th, and 90th percentile standing heights and body masses in adult male and female Caucasian populations were recently developed by modifying the mesh-type ICRP reference computational phantoms (MRCPs). In the present study, these percentile-specific phantoms were used to calculate a comprehensive dataset of body-size-dependent DCs for photon external exposures by performing Monte Carlo dose calculations with the Geant4 code. The dataset includes the DCs of absorbed doses for 29 individual organs/tissues from 0.01 to 104 MeV photon energy, in the antero-posterior, postero-anterior, right lateral, left lateral, rotational, and isotropic geometries. The body-size-dependent DCs were compared with the DCs of the MRCPs in the reference body size, showing that the DCs of the MRCPs are generally similar to those of the 50th percentile standing height and body mass phantoms over the entire photon energy region except for low energies (≤ 0.03 MeV); the differences are mostly less than 10%. In contrast, there are significant differences in the DCs between the MRCPs and the 10th and 90th percentile standing height and body mass phantoms (i.e., H10M10 and H90M90). At energies of less than about 10 MeV, the MRCPs tended to under- and over-estimate the organ/tissue doses of the H10M10 and H90M90 phantoms, respectively. This tendency was revised at higher energies. The DCs of the percentile-specific phantoms were also compared with the previously published values of another phantom sets with similar body sizes, showing significant differences particularly at energies below about 0.1 MeV, which is mainly due to the different locations and depths of organs/tissues between the different phantom libraries. The DCs established in the present study should be useful to improve the dosimetric accuracy in the reconstructions of organ/tissue doses for individuals in risk assessment for epidemiologic investigations taking body sizes into account.

中文翻译：

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光子外部暴露的百分位特定计算模型的剂量系数。


使用基于国际放射防护委员会 (ICRP) 推荐的具有固定体型的参考体模的剂量系数 (DC) 可能会对要使用的估计器官/组织剂量产生误差，例如，用于流行病学研究，具体取决于关于队列成员的体型。最近通过修改网格型 ICRP 参考计算模型 (MRCP) 开发了一组特定于百分位的计算模型，代表成年男性和女性白种人群体中第 10、50 和 90 个百分位的站立高度和体重。在本研究中，通过使用 Geant4 代码执行蒙特卡罗剂量计算，这些特定于百分位数的体模用于计算光子外部暴露的与身体尺寸相关的 DC 的综合数据集。该数据集包括 29 个个体器官/组织从 0.01 到 104 MeV 光子能量、前后、后前、右侧、左侧、旋转和各向同性几何形状的吸收剂量 DC。将与身体尺寸相关的 DC 与参考身体尺寸中 MRCP 的 DC 进行比较，结果表明，MRCP 的 DC 通常与整个光子能量区域内第 50 个百分位站立高度和体重体模的 DC 相似，除了对于低能量（≤ 0.03 MeV）；差异大多小于10%。相反，MRCP 与第 10 个和第 90 个百分位数站立高度和体重体模（即 H10M10 和 H90M90）之间的 DC 存在显着差异。在能量低于约 10 MeV 时，MRCP 往往会分别低估和高估 H10M10 和 H90M90 体模的器官/组织剂量。这种趋势在更高的能量下得到了修正。 百分位数特定体模的 DC 也与先前发布的具有相似身体尺寸的另一组体模的 DC 值进行了比较，显示出显着差异，特别是在低于约 0.1 MeV 的能量下，这主要是由于器官/组织的位置和深度不同不同的虚拟库之间。本研究中建立的 DC 应有助于提高在流行病学调查风险评估中考虑体型的个体器官/组织剂量重建的剂量测定准确性。