RT Journal Article SR Electronic T1 In vivo 18F-flortaucipir PET does not accurately support the staging of progressive supranuclear palsy JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.121.262985 DO 10.2967/jnumed.121.262985 A1 Maura Malpetti A1 Sanne S Kaalund A1 Kamen A Tsvetanov A1 Timothy Rittman A1 Mayen Briggs A1 Kieren Allinson A1 Luca Passamonti A1 Negin Holland A1 P Simon Jones A1 Tim D Fryer A1 Young T Hong A1 Antonina Kouli A1 Richard Bevan-Jones A1 Elijah Mak A1 George Savulich A1 Maria Grazia Spillantini A1 Franklin Aigbirhio A1 Caroline H Williams-Gray A1 John T O'Brien A1 James B Rowe YR 2021 UL http://jnm.snmjournals.org/content/early/2021/11/18/jnumed.121.262985.abstract AB Progressive Supranuclear Palsy (PSP) is a neurodegenerative disorder characterised by neuro-glial tau pathology. A new staging system for PSP pathology at post-mortem has been described and validated. We used a data-driven approach to test whether post-mortem pathological staging in PSP can be reproduced in vivo with 18F-flortaucipir PET. Methods: N = 42 patients with probable PSP and N = 39 controls underwent 18F-flortaucipir PET. Conditional inference tree analyses on regional binding potential values identified absent/present pathology thresholds to define in vivo staging. Following the staging system for PSP pathology, the combination of absent/present values across all regions was evaluated to assign each participant to in vivo stages. Analysis of variance was applied to analyse differences among means of disease severity between stages. In vivo staging was compared with post-mortem staging in N = 9 patients who also had post-mortem confirmation of the diagnosis and stage. Results: Stage assignment was estimable in 41 patients: N = 10 patients were classified in stage I/II, N = 26 in stage III/IV, N = 5 in stage V/VI, while N = 1 was not classifiable. An explorative sub-staging identified N = 2 patients in stage I, N = 8 in stage II, N = 9 in stage III, N = 17 in stage IV and N = 5 in stage V. However, the nominal 18F-flortaucipir derived stage was not associated with clinical severity and was not indicative of pathology staging at post-mortem. Conclusion: 18F-flortaucipir PET in vivo does not correspond to neuropathological staging in PSP. This analytic approach, seeking to mirror in vivo the neuropathology staging with PET-to-autopsy correlational analyses might enable in vivo staging with next-generation PET tracers for tau, but further evidence and comparison with post-mortem data are needed.