基于生物动力学模型的^(18)F-FDGPET扫描患者个体化累积活度分布评估  

Individualized estimation of cumulated activity distribution in patients undergoing ^(18)F-FDG PET scans based on the biokinetic model

作　　者：何宇涛 倪明 李晓宇 陈志[1] HE Yutao;NI Ming;LI Xiaoyu;CHEN Zhi(School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230026,China;Department of Nuclear Medicine,the First Affiliated Hospital of University of Science and Technology of China,Hefei 230001,China)

机构地区：[1]中国科学技术大学核科学技术学院,安徽合肥230026 [2]中国科学技术大学附属第一医院核医学科,安徽合肥230001

出　　处：《中国医学物理学杂志》2024年第8期931-938,共8页Chinese Journal of Medical Physics

基　　金：中国科学技术大学附属第一医院医学人工智能联合基金(MAI2022Q017)。

摘　　要：目的:利用生物动力学模型,在基于单个时间点PET图像的基础上,实现进行^(18)F-FDGPET扫描患者的个体化累积活度分布计算评估。方法:首先,构建目标器官的生物动力学隔室模型,并将各隔室内的活度变化描述为微分方程组。然后,使用每例患者特定时间点的PET图像数据,采用模拟退火算法对模型系数进行优化,计算各个器官的累积活度情况,分析患者不同排尿情况下对膀胱累积活度的影响。最后,考虑放射性核素在组织器官中分布的异质性,计算人体全身累积活度分布图,并与现有方法进行对比,评估本研究提出方法的准确性。结果:在本研究分析的11例病例中,生物动力学模型的计算结果总体上与实验数据具有良好的一致性,平均差异小于15%。同时,在不同排尿情况下,患者膀胱的累积活度平均值差异最高可达2.4倍,表明强制患者排尿对于降低辐射影响有积极意义。与ICRP128号出版物中获得的生物动力学数据比较显示,脑部和心脏部分器官存在较大差异,标准偏差分别为61.0%和46.3%。结论:基于构建的生物动力学模型能够准确合理地计算PET患者个体化的累积活度分布,提出的评估方法将为进行PET扫描的每例患者的内照射辐射剂量学评估提供有价值的参考。Objective To achieve personalized assessment of cumulated activity distribution in patients undergoing ^(18)F-FDG PET scans using the biokinetic model based on the single-time-point PET images.Methods A biokinetic compartmental model for the organs of interest was established,and the variation of activities in each compartment was described as a set of differential equations.The PET image data at a specific time point of each patient was used to obtain the kinetic model parameters which were then optimized by a simulated annealing algorithm to calculate the cumulated activity of each organ.Additionally,the effects of different voiding patterns on the cumulated activity of the bladder were analyzed.Considering the heterogeneity of radioactive nuclide distribution in organs,a whole-body cumulated activity distribution map was computed,and the accuracy of the proposed method was evaluated by comparison with the existing methods.Results For the 11 cases analyzed in the study,the calculation results of the biokinetic model generally showed a good agreement with experimental data,with an average deviation of less than 15%.Meanwhile,under different urinary excretion conditions,the average cumulated activity in the bladder differed by up to 2.4 times,indicating the positive significance of enforced urination in reducing radiation exposure.The comparison with the biokinetic data obtained from ICRP Publication 128 revealed relatively large deviations for certain organs such as the brain and heart,with standard deviations of 61.0%and 46.3%,respectively.Conclusion The constructed biokinetic model can effectively estimate the individualized cumulated activity distribution in patients undergoing PET scans,providing valuable insights for the internal dosimetry assessment.

关 键 词：^(18)F-FDG 累积活度 生物动力学模型 内照射剂量 

分 类 号：R811.1[医药卫生—放射医学]