Lopes Alves Isadora, Willemsen Antoon Tm, Dierckx Rudi A, da Silva Ana Maria M, Koole Michel
1 Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
2 Laboratory of Medical Imaging, School of Physics, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
J Cereb Blood Flow Metab. 2017 Mar;37(3):866-876. doi: 10.1177/0271678X16644463. Epub 2016 Jul 21.
Receptor occupancy studies performed with PET often require time-consuming dynamic imaging for baseline and post-dose scans. Shorter protocol approximations based on standard uptake value ratios have been proposed. However, such methods depend on the time-point chosen for the quantification and often lead to overestimation and bias. The aim of this study was to develop a shorter protocol for the quantification of post-dose scans using a dual time-point approximation, which employs kinetic parameters from the baseline scan. Dual time-point was evaluated for a [C]raclopride PET dose occupancy study with the D2 antagonist JNJ-37822681, obtaining estimates for binding potential and receptor occupancy. Results were compared to standard simplified reference tissue model and standard uptake value ratios-based estimates. Linear regression and Bland-Altman analysis demonstrated excellent correlation and agreement between dual time-point and the standard simplified reference tissue model approach. Moreover, the stability of dual time-point-based estimates is shown to be independent of the time-point chosen for quantification. Therefore, a dual time-point imaging protocol can be applied to post-dose [C]raclopride PET scans, resulting in a significant reduction in total acquisition time while maintaining accuracy in the quantification of both the binding potential and the receptor occupancy.
正电子发射断层扫描（PET）进行的受体占有率研究通常需要对基线扫描和给药后扫描进行耗时的动态成像。已有人提出基于标准摄取值比率的较短方案近似法。然而，此类方法取决于为定量选择的时间点，并且常常导致高估和偏差。本研究的目的是开发一种使用双时间点近似法对给药后扫描进行定量的较短方案，该方法采用基线扫描的动力学参数。对使用D2拮抗剂JNJ-37822681的[碳]雷氯必利PET剂量占有率研究评估双时间点，获得结合潜力和受体占有率的估计值。将结果与标准简化参考组织模型和基于标准摄取值比率的估计值进行比较。线性回归和布兰德-奥特曼分析表明双时间点与标准简化参考组织模型方法之间具有极好的相关性和一致性。此外，基于双时间点的估计值的稳定性表明与为定量选择的时间点无关。因此，双时间点成像方案可应用于给药后[碳]雷氯必利PET扫描，在保持结合潜力和受体占有率定量准确性的同时，显著减少总采集时间。
