Beyer Leonie, Nitschmann Alexander, Barthel Henryk, van Eimeren Thilo, Unterrainer Marcus, Sauerbeck Julia, Marek Ken, Song Mengmeng, Palleis Carla, Respondek Gesine, Hammes Jochen, Barbe Michael T, Onur Özgür, Jessen Frank, Saur Dorothee, Schroeter Matthias L, Rumpf Jost-Julian, Rullmann Michael, Schildan Andreas, Patt Marianne, Neumaier Bernd, Barret Olivier, Madonia Jennifer, Russell David S, Stephens Andrew W, Roeber Sigrun, Herms Jochen, Bötzel Kai, Levin Johannes, Classen Joseph, Höglinger Günter U, Bartenstein Peter, Villemagne Victor, Drzezga Alexander, Seibyl John, Sabri Osama, Brendel Matthias
Department of Nuclear Medicine, University Hospital of Munich LMU Munich, Marchioninstraße 15, 81377, Munich, Germany.
Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.
Eur J Nucl Med Mol Imaging. 2020 Nov;47(12):2911-2922. doi: 10.1007/s00259-020-04788-w. Epub 2020 Apr 21.
Second-generation tau radiotracers for use with positron emission tomography (PET) have been developed for visualization of tau deposits in vivo. For several β-amyloid and first-generation tau-PET radiotracers, it has been shown that early-phase images can be used as a surrogate of neuronal injury. Therefore, we investigated the performance of early acquisitions of the novel tau-PET radiotracer [F]PI-2620 as a potential substitute for [F]fluorodeoxyglucose ([F]FDG).
Twenty-six subjects were referred with suspected tauopathies or overlapping parkinsonian syndromes (Alzheimer's disease, progressive supranuclear palsy, corticobasal syndrome, multi-system atrophy, Parkinson's disease, multi-system atrophy, Parkinson's disease, frontotemporal dementia) and received a dynamic [F]PI-2620 tau-PET (0-60 min p.i.) and static [F]FDG-PET (30-50 min p.i.). Regional standardized uptake value ratios of early-phase images (single frame SUVr) and the blood flow estimate (R) of [F]PI-2620-PET were correlated with corresponding quantification of [F]FDG-PET (global mean/cerebellar normalization). Reduced tracer uptake in cortical target regions was also interpreted visually using 3-dimensional stereotactic surface projections by three more and three less experienced readers. Spearman rank correlation coefficients were calculated between early-phase [F]PI-2620 tau-PET and [F]FDG-PET images for all cortical regions and frequencies of disagreement between images were compared for both more and less experienced readers.
Highest agreement with [F]FDG-PET quantification was reached for [F]PI-2620-PET acquisition from 0.5 to 2.5 min p.i. for global mean (lowest R = 0.69) and cerebellar scaling (lowest R = 0.63). Correlation coefficients (summed 0.5-2.5 min SUVr & R) displayed strong agreement in all cortical target regions for global mean (R 0.76, R = 0.77) and cerebellar normalization (R 0.68, R = 0.68). Visual interpretation revealed high regional correlations between early-phase tau-PET and [F]FDG-PET. There were no relevant differences between more and less experienced readers.
Early-phase imaging of [F]PI-2620 can serve as a surrogate biomarker for neuronal injury. Dynamic imaging or a dual time-point protocol for tau-PET imaging could supersede additional [F]FDG-PET imaging by indexing both the distribution of tau and the extent of neuronal injury.
已开发出用于正电子发射断层扫描（PET）的第二代tau放射性示踪剂，用于在体内可视化tau沉积物。对于几种β-淀粉样蛋白和第一代tau-PET放射性示踪剂，已表明早期图像可作为神经元损伤的替代指标。因此，我们研究了新型tau-PET放射性示踪剂[F]PI-2620早期采集作为[F]氟脱氧葡萄糖（[F]FDG）潜在替代品的性能。
26名疑似患有tau蛋白病或重叠帕金森综合征（阿尔茨海默病、进行性核上性麻痹、皮质基底节综合征、多系统萎缩、帕金森病、多系统萎缩、帕金森病、额颞叶痴呆）的受试者接受了动态[F]PI-2620 tau-PET（注射后0 - 60分钟）和静态[F]FDG-PET（注射后30 - 50分钟）检查。[F]PI-2620-PET早期图像的区域标准化摄取值比率（单帧SUVr）和血流估计值（R）与[F]FDG-PET的相应定量指标（全局均值/小脑归一化）相关。还由三名经验较多和三名经验较少的读者使用三维立体定向表面投影对皮质靶区域示踪剂摄取减少情况进行视觉解读。计算所有皮质区域早期[F]PI-2620 tau-PET与[F]FDG-PET图像之间的Spearman等级相关系数，并比较经验较多和经验较少的读者图像之间的不一致频率。
对于[F]PI-2620-PET，在注射后0.5至2.5分钟采集时，与[F]FDG-PET定量指标的一致性最高，全局均值（最低R = 0.69）和小脑缩放（最低R = 0.63）。相关系数（0.5 - 2.5分钟SUVr与R之和）在所有皮质靶区域对于全局均值（R 0.76，R = 0.77）和小脑归一化（R 0.68，R = 0.68）显示出高度一致性。视觉解读显示早期tau-PET与[F]FDG-PET之间存在高度区域相关性。经验较多和经验较少的读者之间没有相关差异。
[F]PI-2620的早期成像可作为神经元损伤的替代生物标志物。tau-PET成像的动态成像或双时间点方案可通过对tau分布和神经元损伤程度进行索引，取代额外的[F]FDG-PET成像。
