HAI Book 2025 - Flipbook - Page 228
Ghatamaneni, Sujala
50
Impact of age and sex on extra-cerebral off-target binding in tau PET
scans (18F-FTP)
Sujala Ghatamaneni3, Daniel Kim3, Marin Nycklemoe3, Emily S Lundt4, Christopher G Schwarz3,
Mahathi Kandimalla3, David Jacobson3, Sabrina Albertson3, Clifford R Jack3, Jeffrey Gunter3,
Ronald Peterson3, Tiffany kung3, Vamika sharma3, Lim Seokbeen3, Val Lowe, Hoon-ki Min
2
Department of Radiology, Mayo Clinic, Rochester, MN, US
Department of Clinical trials and Biostatistics, Mayo Clinic, Rochester, MN, US
3
Department of Cardiology, Mayo Clilnc, Rochester, MN, US
4
Department of Neurology, Mayo Clinic, Rochester, MN, US
2
Background: Tau PET imaging with 18F-flortacipir (18F-FTP) has directed interest in accurately tracking
longitudinal tau changes with Alzheimer9s disease, thus minimizing variability is critical. Off-target signal has the
potential to complicate interpretation of 18F-FTP imaging due to potential spillover effects, with increased effect
seen in later stages of Alzheimer9s due to cerebral atrophy and proximity of off-target areas to relevant cortical
areas. Previously, we demonstrated the effect of uptake period activity on 18F-FTP signal. With increasing recent
interest in demographic factors that may affect off-target binding, we investigated the effect of age and sex in
extra-cerebral off-target signal in 18F-FTP PET imaging.
Method: Standard 18F-FTP PET protocol was performed in 330 participants. Two independent readers measured
tau uptake in predetermined off-target regions, including extraocular muscle, meninges, and occipital bone
among others. Correlation and grouped assessed the relationship between participants9 age with off-target tau
uptake (SUV) and sex with SUV.
Result: Age had a significant effect on off-target in most brain regions, with variable positive or negative
correlation based on area. Notably, SUV in the oculomotor muscles, masseter muscle, and pterygoid all showed
significant positive correlation with age, but SUV in meninges and occipital bone showed significant negative
correlation with age (n=330, p
