在肿瘤PET中,在注射后期间,有活力的肿瘤的SUV和标准化摄取比(SUR)通常会增加。相比之下,净流入率(Ki),它来自动态PET数据,应该保持相对恒定。已提出将吸收时间校正的SUV(cSUV)和SUR(cSUR)作为吸收时间无关,Ki的静态替代品我们的主要目的是量化Ki的扫描内可重复性,SUV,cSUV,SUR,PET/CT恶性病变中的cSUR。探索性目的是评估cSUR估计Ki方法的能力:这种前瞻性,单中心研究纳入接受标准治疗肿瘤PET/CT的成人.SUV和Ki图像从注射前(~35-50分钟后)和注射后(~75-90分钟后)标准护理成像获得的动态PET数据重建。手动分割肿瘤。提取了定量指标。计算注射后60分钟的cSUVs和cSURs参考摄取时间。计算扫描内测试-重测百分比变化的幅度(测试-重测|%Δ|)。还计算了决定系数(R2)和组内相关系数(ICC)。通过Wilcoxon符号秩检验(α,0.05)。结果:本研究共纳入78名受试者;41名受试者(平均年龄,63.8年;24名男性),116个病变进行了分析。对于两个示踪剂,SUVmax和最大SUR(SURmax)有很大的早期到晚期增加(即,行内可重复性差)。在[18F]FDG-aid病变中(n=93),最大Ki(Ki,max)(13%;0.97)和最大cSUV(cSUVmax)(12%,P=0.90;0.96)或最大cSUR(cSURmax)(13%,P=0.67;0.94)。对于喜欢DOTATATE的病变(n=23),Ki之间的扫描内可重复性没有差异,max(11%;0.98)和cSUVmax(13%,P=0.41;0.98)或cSURmax(11%,P=0.08;0.94)。SUVmax,cSUVmax,SURMAX,和cSURmax都与Ki密切相关,[18F]FDG(R2,0.81-0.92)和DOTATATE(R2,0.88-0.96)的最大值,但是cSURmax与Ki达成了最好的协议,[18F]FDG(ICC,0.69-0.75)和DOTATATE(ICC,0.90-0.91)。结论:Ki,max,cSUVmax,与SUVmax和SURmax相比,cSURmax具有较低的摄取时间依赖性。max可以从cSURmax预测。
In oncologic PET, the SUV and standardized uptake ratio (SUR) of a viable tumor generally increase during the postinjection period. In contrast, the net influx rate (Ki ), which is derived from dynamic PET data, should remain relatively constant. Uptake-time-corrected SUV (cSUV) and SUR (cSUR) have been proposed as uptake-time-independent, static alternatives to Ki Our primary aim was to quantify the intrascan repeatability of Ki , SUV, cSUV, SUR, and cSUR among malignant lesions on PET/CT. An exploratory aim was to assess the ability of cSUR to estimate Ki Methods: This prospective, single-center study enrolled adults undergoing standard-of-care oncologic PET/CT. SUV and Ki images were reconstructed from dynamic PET data obtained before (∼35-50 min after injection) and after (∼75-90 min after injection) standard-of-care imaging. Tumors were manually segmented. Quantitative metrics were extracted. cSUVs and cSURs were calculated for a 60-min postinjection reference uptake time. The magnitude of the intrascan test-retest percent change (test-retest |%Δ|) was calculated. Coefficients of determination (R 2) and intraclass correlation coefficients (ICC) were also computed. Differences between metrics were assessed via the Wilcoxon signed-rank test (α, 0.05). Results: This study enrolled 78 subjects; 41 subjects (mean age, 63.8 y; 24 men) with 116 lesions were analyzed. For both tracers, SUVmax and maximum SUR (SURmax) had large early-to-late increases (i.e., poor intrascan repeatability). Among [18F]FDG-avid lesions (n = 93), there were no differences in intrascan repeatability (median test-retest |%Δ|; ICC) between the maximum Ki (Ki ,max) (13%; 0.97) and either the maximum cSUV (cSUVmax) (12%, P = 0.90; 0.96) or the maximum cSUR (cSURmax) (13%, P = 0.67; 0.94). For DOTATATE-avid lesions (n = 23), there were no differences in intrascan repeatability between the Ki ,max (11%; 0.98) and either the cSUVmax (13%, P = 0.41; 0.98) or the cSURmax (11%, P = 0.08; 0.94). The SUVmax, cSUVmax, SURmax, and cSURmax were all strongly correlated with the Ki ,max for both [18F]FDG (R 2, 0.81-0.92) and DOTATATE (R 2, 0.88-0.96), but the cSURmax provided the best agreement with the Ki ,max across early-to-late time points for [18F]FDG (ICC, 0.69-0.75) and DOTATATE (ICC, 0.90-0.91). Conclusion: Ki ,max, cSUVmax, and cSURmax had low uptake time dependence compared with SUVmax and SURmax The Ki ,max can be predicted from cSURmax.