Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München-German Research Center for Environmental Health (GmbH), D-85764 Neuherberg, Germany.
Health Phys. 2011 Dec;101(6):677-92. doi: 10.1097/HP.0b013e318226edc0.
The reliability of biokinetic models is essential for the assessment of internal doses and a radiation risk analysis for the public and occupational workers exposed to radionuclides. In the present study, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. In the first part of the paper, the parameter uncertainty was analyzed for two biokinetic models of zirconium (Zr); one was reported by the International Commission on Radiological Protection (ICRP), and one was developed at the Helmholtz Zentrum München-German Research Center for Environmental Health (HMGU). In the second part of the paper, the parameter uncertainties and distributions of the Zr biokinetic models evaluated in Part I are used as the model inputs for identifying the most influential parameters in the models. Furthermore, the most influential model parameter on the integral of the radioactivity of Zr over 50 y in source organs after ingestion was identified. The results of the systemic HMGU Zr model showed that over the first 10 d, the parameters of transfer rates between blood and other soft tissues have the largest influence on the content of Zr in the blood and the daily urinary excretion; however, after day 1,000, the transfer rate from bone to blood becomes dominant. For the retention in bone, the transfer rate from blood to bone surfaces has the most influence out to the endpoint of the simulation; the transfer rate from blood to the upper larger intestine contributes a lot in the later days; i.e., after day 300. The alimentary tract absorption factor (fA) influences mostly the integral of radioactivity of Zr in most source organs after ingestion.
生物动力学模型的可靠性对于评估内剂量以及对接触放射性核素的公众和职业工作人员进行辐射风险分析至关重要。本研究提出了一种通过不确定性和敏感性分析来评估生物动力学模型可靠性的方法。在本文的第一部分，分析了两种锆（Zr）生物动力学模型的参数不确定性；一种是国际辐射防护委员会（ICRP）报告的，另一种是慕尼黑亥姆霍兹环境健康研究中心（HMGU）开发的。在本文的第二部分，将第一部分中评估的 Zr 生物动力学模型的参数不确定性和分布用作模型输入，以确定模型中最具影响力的参数。此外，还确定了对摄入后 50 年内源器官中 Zr 放射性积分最具影响力的模型参数。全身性 HMGU-Zr 模型的结果表明，在最初的 10 天内，血液和其他软组织之间的转移率参数对血液中 Zr 的含量和每日尿排泄量影响最大；然而，在 1000 天后，从骨骼到血液的转移率成为主导。对于在骨骼中的滞留，从血液到骨表面的转移率在模拟结束时的影响最大；从血液到上消化道的转移率在后期（即 300 天后）贡献很大。胃肠道吸收系数（fA）主要影响摄入后大多数源器官中 Zr 的放射性积分。
