RT Journal Article
SR Electronic
T1 Comparison Between Brain and Cerebellar Autoradiography Using [<sup>18</sup>F]Flortaucipir, [<sup>18</sup>F]MK6240, and [<sup>18</sup>F]PI2620 in Postmortem Human Brain Tissue
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 123
OP 129
DO 10.2967/jnumed.124.267539
VO 66
IS 1
A1 Aliaga, Antonio
A1 Therriault, Joseph
A1 Quispialaya, Kely Monica
A1 Aliaga, Arturo
A1 Hopewell, Robert
A1 Rahmouni, Nesrine
A1 Macedo, Arthur C.
A1 Kunach, Peter
A1 Soucy, Jean-Paul
A1 Massarweh, Gassan
A1 Diaz, Aida Abreu
A1 Pascoal, Tharick A.
A1 Rocha, Andreia
A1 Guiot, Marie-Christine
A1 Machado, Luiza S.
A1 De Bastiani, Marco Antônio
A1 de Souza, Débora Guerini
A1 Souza, Diogo O.
A1 Gauthier, Serge
A1 Zimmer, Eduardo R.
A1 Rosa-Neto, Pedro
YR 2025
UL http://jnm.snmjournals.org/content/66/1/123.abstract
AB Our objective was to evaluate the in vitro binding properties of [18F]flortaucipir, 6-(fluoro-18F)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine ([18F]MK6240), and 2-(2-([18F]fluoro)pyridin-4-yl)-9H-pyrrolo[2,3-b:4,5c′]dipyridine ([18F]PI2620) head-to-head in postmortem human brain tissue. Methods: Autoradiography was used to assess uptake of [18F]flortaucipir, [18F]MK6240, and [18F]PI2620 in control and Alzheimer disease (AD) autopsy-confirmed brain tissues. The study focused on the analysis of the prefrontal cortex, hippocampus, and cerebellum sections in 12 controls and 12 AD cases, as well as whole-brain hemisphere in 1 control and 1 AD sample, for each radiotracer. The binding values of [18F]flortaucipir, [18F]MK6240, and [18F]PI2620 were calculated from regions of interest manually drawn in the prefrontal, hippocampal, and cerebellar cortices. Results: For all 3 radioligands investigated, we observed significant tracer binding differences between control and AD tissues in the whole-brain hemisphere, prefrontal cortex, and hippocampus but not in the cerebellar cortex. [18F]MK6240 and [18F]PI2620 had higher effect sizes to differentiate control and AD cases than did [18F]flortaucipir. Bland–Altman analyses revealed strong correlations between [18F]MK6240, [18F]PI2620, and [18F]flortaucipir, with the highest agreement found for [18F]MK6240 versus [18F]PI2620. Conclusion: The 3 radioligands showed comparable diagnostic properties to assess tau aggregates in vitro. Binding to AD brain tissues was higher for [18F]MK6240 and [18F]PI2620 than for [18F]flortaucipir. Additionally, [18F]MK6240 and [18F]PI2620 had greater selectivity, displaying decreased uptake in control brain tissue compared with [18F]flortaucipir. These results might provide insights on ongoing initiatives to create a universal scale for tau imaging studies.