HAI Book 2025 - Flipbook - Page 634
Cassa Macedo, Arthur
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Head-to-head comparison of four tau-PET tracers for in vivo Braak
staging: the HEAD Study
Arthur Cassa Macedo1, Nesrine Rahmouni1, Cecile Tissot2, Joseph Therriault1, Stijn Servaes1,
Yi-Ting Wang1, Lydia Trudel1, Etienne Aumont1, Brandon Hall1, Tevy Chan1, Yansheng Zheng1,
Firoza Z Lussier3, Pamela CL Ferreira3, Bruna Bellaver3, Guilherme Povala3, Belen Pascual4,
Brian Gordon5, Val Lowe6, Hwamee Oh7, David Soleimani-Meigooni8, Suzanne Baker2, Tharick
Pascoal3, Pedro Rosa-Neto1
1
Department of Neurology and Neurosurgery, McGill University, Montreal, QC, CA
Lawrence Berkeley National Laboratory, Berkeley, CA, US
3
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, US
4
Department of Neurology, Houston Methodist Research Institute, Houston, TX, US
5
Department of Radiology, Washington University in St. Louis, St. Louis, MO, US
6
Department of Radiology, Mayo Clinic, Rochester, MN, US
7
Department of Psychiatry and Human Behavior, Brown University, Providence, RI, US
8
Memory and Aging Center, University of California San Francisco, San Francisco, CA, US
2
Background: Tau-PET tracers allow for in vivo Braak staging of individuals in the Alzheimer9s disease (AD)
continuum. The agreement of different tracers for in vivo Braak staging remains unclear. Therefore, we
performed a head-to-head comparison of Braak staging using first- and second-generation tau-PET tracers.
Methods: We assessed 42 cognitively impaired and 34 cognitively unimpaired participants (mean [SD] age 67.9
[7.7] years) with four tau-PET tracers ([18F]MK6240, [18F]AV1451, [18F]RO948, and [18F]PI2620) at McGill
University, as part of the HEAD study. We calculated standardized uptake value ratio (SUVR) in Braak-like regions
of interest (ROI) for each ligand and investigated their Spearman9s correlation. Thresholds defined the presence of
tauopathy in each Braak ROI, which we used to assign a Braak stage to each participant (Fig.1). Finally, we
assessed the agreement between the Braak staging provided by each tracer for the traditional and simplified
frameworks (i.e. considering merged Braak ROIs).
HAI2025 - 634
