Evaluation of the Correction Methods Using Age and BMI for Estimating CT Organ Dose Using a Radiophotoluminescence Glass Dosimeter and a Monte Carlo-based Dose Calculator
Evaluation of the Correction Methods Using Age and BMI for Estimating CT Organ Dose Using a Radiophotoluminescence Glass Dosimeter and a Monte Carlo-based Dose Calculator
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使用放射光致发光玻璃剂量计和基于蒙特卡罗的剂量计算器使用年龄和 BMI 估算 CT 器官剂量的校正方法的评估
DOI：
10.1097/hp.0000000000001460
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发表时间：
2021
期刊：
影响因子：
2.2
通讯作者：
Weishan Chang and Yusuke Koba
中科院分区：
文献类型：
--
作者：
Motegi Takaharu;Fukui Naoki;Hashijiri Koyo;Tsuboya Ryusuke;Sugai Takuro;Egawa Jun;Mitome Setsuko;Araki Rie;Haino Kazufumi;Yamaguchi Masayuki;Takakuwa Koichi;Enomoto Takayuki;Someya Toshiyuki;Weishan Chang and Yusuke Koba
尺寸特定剂量估计（SSDE）已被推荐取代体积计算机断层扫描剂量指数（CTDI vol），因为它考虑到患者的大小。另一方面，由于器官剂量与辐射风险的相关性，器官剂量被认为是辐射防护领域中更合适的量。基于网络的计算机断层扫描（CT）剂量计算器WAZA-ARIv 2仅为四种不同体型的成年人和五种不同年龄的儿童提供器官剂量。由于美国医学物理学家协会（AAPM）提供了SSDE的转换因子，并且SSDE与器官剂量的相关性已得到证实，因此转换表的实施可能会提高WAZA-ARIv 2的准确性。本研究旨在评价一种基于体重指数（BMI）和基于年龄的校正方法，通过使用放射光致发光剂量计（RGD）、拟人体模和剂量计算器WAZA-ARIv 2来估计器官剂量。通过使用ISOVOLT TITAN-320 X射线发生器单独校准RGD。SSDE转换因子的比值（CF SSDE）被用作比较指标。对于基于BMI的校正方法，成人体模的CF SSDE值的比值预计为1.065，成人体模的器官剂量的平均比值为1.163±0.169。对于基于年龄的校正方法，5岁和10岁儿童模型的CF SSDE值的比值预计为0.889，WAZA-ARIv 2剂量测定系统和RGD剂量测定系统的器官剂量比值分别为0.866±0.024和0.909±0.047。总之，实验结果的两个评估显示WAZA-ARIv 2和SSDE转换因子表之间的一致性。此外，根据这项研究，在应用质量衰减系数时考虑测量位置的重要性被证明。
The size-specific dose estimates (SSDE) have been recommended to replace the volume computed tomography dose index (CTDI vol) because it takes patient size into account. On the other hand, organ dose is thought to be a more appropriate quantity in the radiation protection field due to its correlation with radiation risk. The web-based computed tomography (CT) dose calculator WAZA-ARIv2 only offers organ doses for adults with four different body shapes and for children with five different ages. Since the American Association of Physicists in Medicine (AAPM) offers the conversion factors for SSDE and the correlation of SSDE with organ dose has been demonstrated, implementation of the conversion table might improve the accuracy of WAZA-ARIv2. This study aimed to evaluate a body mass index (BMI)-based and age-based correction method for estimation of the organ dose by using a radiophotoluminescence dosimeter (RGD), an anthropomorphic phantom, and the dose calculator WAZA-ARIv2. RGDs were individually calibrated by using an ISOVOLT TITAN-320 x-ray generator. The ratio of the SSDE conversion factors (CF SSDE) was used as the comparison index. For the BMI-based correction method, the ratio of CF SSDE values for the adult phantoms was expected to be 1.065, and the average ratio of the organ doses for the adult phantoms was 1.163±0.169. For the age-based correction method, the ratio of CF SSDE value for 5-and 10-y-old pediatric phantoms was expected to be 0.889, and the ratios of the organ doses were 0.866±0.024 and 0.909±0.047 for the WAZA-ARIv2 dosimetry system and RGD dosimetry system, respectively. In conclusion, both evaluations of the experimental results showed the consistency between WAZA-ARIv2 and the SSDE conversion factor table. Moreover, the importance of taking the measurement position into account when applying the mass attenuation coefficient was demonstrated according to this study.