Author:
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
Abstract
Abstract
Purpose
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 [18F]PI-2620 as a potential substitute for [18F]fluorodeoxyglucose ([18F]FDG).
Methods
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 [18F]PI-2620 tau-PET (0–60 min p.i.) and static [18F]FDG-PET (30–50 min p.i.). Regional standardized uptake value ratios of early-phase images (single frame SUVr) and the blood flow estimate (R1) of [18F]PI-2620-PET were correlated with corresponding quantification of [18F]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 [18F]PI-2620 tau-PET and [18F]FDG-PET images for all cortical regions and frequencies of disagreement between images were compared for both more and less experienced readers.
Results
Highest agreement with [18F]FDG-PET quantification was reached for [18F]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 & R1) displayed strong agreement in all cortical target regions for global mean (RSUVr 0.76, RR1 = 0.77) and cerebellar normalization (RSUVr 0.68, RR1 = 0.68). Visual interpretation revealed high regional correlations between early-phase tau-PET and [18F]FDG-PET. There were no relevant differences between more and less experienced readers.
Conclusion
Early-phase imaging of [18F]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 [18F]FDG-PET imaging by indexing both the distribution of tau and the extent of neuronal injury.
Funder
Lüneburg heritage
Deutsche Forschungsgemeinschaft
German Federal Ministriy of Education and Research
NOMIS foundation
Publisher
Springer Science and Business Media LLC
Subject
Radiology, Nuclear Medicine and imaging,General Medicine,Radiology, Nuclear Medicine and imaging,General Medicine