Comparison of group‐level and individualized ROIs for predicting change in longitudinal tau‐PET in preclinical and prodromal AD

Longitudinal tau‐PET is increasingly used as an outcome in clinical trials evaluating disease‐modifying therapies in Alzheimer’s disease (AD). In order to quantify change in tau‐PET signal over time, regions of interest (ROIs) are used; to date, these have been based on neuropathological studies or data‐driven approaches where the same ROI is used for each subject (group‐level ROI). However, given the inter‐individual heterogeneity in spatial patterns of tau‐PET, a key question is whether the use of subject‐specific (individualized) ROIs might offer any advantages over group‐level ROIs in AD clinical trials. We aimed to address this question by comparing group‐level and individualized ROIs across several metrics using longitudinal tau‐PET in preclinical and prodromal AD.