TrueX与OSEM重建方法对肿瘤病灶SUV测量的比较

目的：探讨目前常用的两种重建方法（TrueX和OSEM）对肿瘤病灶SUV值的影响，为PET/CT显像技术操作的规范化提供依据。材料：NEMA IEC Body Phantom Set模型及40例确诊全身多发病灶肿瘤病人（肿瘤及其转移病灶>10处），行PET/CT扫描后分别采用TrueX和OSEM重建。每个病人选取10～15个实性病灶（CT显示），利用TrueD软件测量SUV值和体积。结果：模型与40例肿瘤病人两种重建方法总体上对于SUVmax（t=-0.145，P>0.05）和SUVavg（t=-0.141，P>0.05）不存在统计学差异。427个病灶中有65%的病灶显示TrueX的SUVmax小于OSEM。在TrueX重建方法所测得的VOI50%＜1cm3时两者所得的SUVmax差异具有统计学意义（t=2.143，P<0.05）。在TrueX中SUVmax>15时（21个病灶），两种重建方法SUVmax的差值为3.09±1.48，两者的SUVmax差异具有统计学意义（t=9.548，P<0.05）。结论：TrueX与OSEM重建方法相比，对于较小肿瘤病灶及较高SUV时的肿瘤病灶，SUV平均值和最大值存在差异。因此应用PET/CT对肿瘤病人进行疗效监控及随访时，应保证重建方法的一致性。

Comparison of SUV between TrueX and OSEM in oncological patients

Objective：To evaluate standardized uptake value（SUV） in both TrueX and OSEM.Methods：①NEMA IEC Body Phantom experiment.②Clinical study：40 oncological patients were reconstructed by TrueX and OSEM.SUV and volume of 10～15 lesions in every patient were measured by TrueD software.Results：There was no significant difference of SUVmax（t=-0.145,P0.05） and SUVavg（t=-0.141,P0.05） between TrueX and OSEM according to both phantom experiment and clinical study.SUVmax of 65% lesions measured by TruxX was less than that by OSEM.There was significant difference of SUVmax when VOI50% was below 1cm3 or when SUVmax was above 15.Conclusion：There was significant difference of SUVavg and SUVmax between TrueX and OSEM in small lesions and lesions with high SUV.The results revealed that it is important to keep the same reconstruction method in follow up for response criteria.