18F-FDG PET/CT受检者关键器官辐射剂量方程的计算

摘要

在PET/CT扫描中,18F-FDG(Fludeoxyglucose)作为放射性显像药物对受检者的关键器官产生内照射辐射.为了避免受检者在检查过程中受到多余的放射性辐射,同时为肿瘤科医师提供更为全面的有效剂量数据,基于辐射防护基础中的内照射剂量当量计算公式及算法中相关物理量的定义进行理论推导,并结合ICRP(International commission on radiological protection)所给出的各物理参数的数值,得到关键器官的有效剂量及有效剂量率随时间变化的线性方程.对比关键器官脑、肺、肝、膀胱和全身在不同时间点的有效剂量及有效剂量率,得知关键器官的有效剂量在常规扫描时间内变化较快,随后在放射性核素半衰期内平稳上升.膀胱的有效剂量变化远比其他关键器官的更为明显.%In PET/CT Scanning,18F-FDG(Fludeoxyglucose) is used as the radiopharmaceuticals to produce internal radiation to critical organs of the subject.In order to prevent the recipients from being exposed to excess radiation during the inspection and provide more effective dose data for oncologists,time varying linear equations of effective dose and effective dose rate of critical organs are deduced based on the algorithm given by dose equivalent calculation from the basis of radiation protection and the numerical values of the physical parameters given by ICRP (International commission on radiological protection).Comparing the effective dose and effective dose rate of brain,lung,liver,bladder and the whole body at different time points,it can be known that the effective dose of the critical organs will change rapidly during regular scanning time,then raise steadily in the half-life period of the radionuclide.Effective does changes of bladder are more obvious than that of other critical organs.