Extent ‐ A Global Spatial Distribution Measure to Estimate Progression and Demonstrate Treatment Effect in Flortaucipir Scans

We previously reported that donanemab slows global and regional increase in flortaucipir standardized uptake value ratios (SUVRs)1. In addition to SUVR, a method to estimate spatial distribution of flortaucipir (FTP) uptake might provide valuable and complementary information. Here, we apply the previously developed Extent method to estimate the spread of FTP uptake in PET images and present comparisons against neocortical SUVR for the measurement of treatment effect in the TRAILBLAZER‐ALZ trial. We performed vertex‐wise statistical comparisons.