HAI Book 2025 - Flipbook - Page 657
Scop Medeiros, Marina
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Comparison of MK-6240 PET and Flortaucipir tau PET imaging for
the biological staging of Alzheimer9s disease
Marina Scop Medeiros1, Pamela L. Ferreira1, Bruna Bellaver1, Emma Ruppert1, Hussein
Zalzale1, Carolina Soares1, Guilherme Povala1, Guilherme Bauer-Negrini1, Andreia Rocha1,
Matheus S. Rodrigues1, Markley Oliveira1, Rayan Mroue1, Pampa Saha1, Livia Amaral1, Firoza
Lussier1, Madeleine Bloomquist1, Dana L. Tudorascu1, Joseph Masdeu2, David SoleimaniMeigooni4, Juan Fortea5, Val Lowe6, Hwamee Oh7, Belen Pascual2, Brian A. Gordon8, Pedro
Rosa-Neto9, Lucas P. Schilling1, Suzanne Baker10, Tharick A. Pascoal1
1
University of Pittsburgh, Pittsburgh, PA, US
Houston Methodist Research Institute, Houston, TX, US
3
University of California San Francisco, San Francisco, CA, US
4
Hospital de la Santa Creu i Sant Pau, Barcelona, ES
5
Mayo Clinic, Rochester, MN, US
6
Brown University, Department of Psychiatry and Human Behavior, Providence, RI, US
7
Washington University in St. Louis, St Louis, MO, US
8
Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Montreal, QC, CA
9
BRAIN Institute, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, BR
10
Lawrence Berkeley National Laboratory, Berkeley, CA, US
2
Background: The Alzheimer9s Association workgroup criteria (AA-2024) suggest four biological stages
based on PET imaging. Recognizing that the application of this framework may vary depending on the
tau PET tracer used, we aim to compare clinical-biological agreements using two different tau PET
tracers.Methods: We stratified 148 A´+ participants from the HEAD study with MK-6240 and Flortaucipir tauPET. Four clinical stages (normal, transitional, MCI, and dementia) were defined based on the AA-2024 criteria.
Three different stage-2 constructs were tested in separated analyses for subjective cognitive decline (SCD),
subtle objective cognitive deficit (SOCD), and mild behavioral impairment (MBI) (see Figure 1A). For biological
staging, SUVR regional abnormalities were defined based on tracer-specific thresholds, testing three different
methods (Youden index, CU A´- mean +2SD, Young mean +2.5SD) and three regions of interest schemes:
(i)proposed by AA-2024, (ii)Braak stages, (iii)or single anatomical regions (Figure 1B). Cohen9s weighted-kappa (K)
statistic measured clinical-biological and between-tracer agreements.
HAI2025 - 657
