Andersson M, Johansson L, Minarik D, Mattsson S, Leide-Svegborn S
Medical Radiation Physics, Department of Clinical Sciences, Malmö, Lund University, Skåne University Hospital, SUS Malmö, SE-205 02 Malmö, Sweden
Medical Radiation Physics, Department of Radiation Sciences, Umeå University, SE-90187 Umeå, Sweden.
Radiat Prot Dosimetry. 2014 Dec;162(3):299-305. doi: 10.1093/rpd/nct337. Epub 2013 Dec 18.
The internal dosimetry computer program internal dose assessment by computer (IDAC) for calculations of absorbed doses to organs and tissues as well as effective doses to patients from examinations with radiopharmaceuticals has been developed. The new version, IDAC2.0, incorporates the International Commission on Radiation Protection (ICRP)/ICRU computational adult male and female voxel phantoms and decay data from the ICRP publication 107. Instead of only 25 source and target regions, calculation can now be made with 63 source regions to 73 target regions. The major advantage of having the new phantom is that the calculations of the effective doses can be made with the latest tissue weighting factors of ICRP publication 103. IDAC2.0 uses the ICRP human alimentary tract (HAT) model for orally administrated activity and for excretion through the gastrointestinal tract and effective doses have been recalculated for radiopharmaceuticals that are orally administered. The results of the program are consistent with published data using the same specific absorption fractions and also compared with published data from the same computational phantoms but with segmentation of organs leading to another set of specific absorption fractions. The effective dose is recalculated for all the 34 radiopharmaceuticals that are administered orally and has been published by the ICRP. Using the new HAT model, new tissue weighting factors and the new adult computational voxel phantoms lead to an average effective dose of half of its earlier estimated value. The reduction mainly depends on electron transport simulations to walled organs and the transition from the stylised phantom with unrealistic interorgan distances to more realistic voxel phantoms.
已开发出内部剂量学计算机程序“计算机内部剂量评估（IDAC）”，用于计算放射性药物检查中器官和组织的吸收剂量以及患者的有效剂量。新版本IDAC2.0纳入了国际辐射防护委员会（ICRP）/国际辐射单位与测量委员会（ICRU）的成年男性和女性体素模型，以及ICRP第107号出版物中的衰变数据。现在，计算可以从仅25个源区和靶区，变为用63个源区到73个靶区进行。采用新模型的主要优势在于，可以使用ICRP第103号出版物的最新组织权重因子来计算有效剂量。IDAC2.0对口服给药活动和经胃肠道排泄采用ICRP人体消化道（HAT）模型，并重新计算了口服放射性药物的有效剂量。该程序的结果与使用相同特定吸收分数的已发表数据一致，并且还与来自相同计算模型但器官分割导致另一组特定吸收分数的已发表数据进行了比较。对ICRP已发表的所有34种口服放射性药物重新计算了有效剂量。使用新的HAT模型、新的组织权重因子和新的成年计算体素模型，导致平均有效剂量为其早期估计值的一半。这种降低主要取决于对有壁器官的电子传输模拟，以及从器官间距离不现实的理想化模型到更现实的体素模型的转变。
