A multicenter comparison of [18F]flortaucipir, [18F]RO948, and [18F]MK6240 tau PET tracers to detect a common target ROI for differential diagnosis
Antoine Leuzy, Tharick A. Pascoal, Olof Strandberg, Philip S. Insel, Ruben Smith, Niklas Mattsson, Andréa Lessa Benedet, Hanna Cho, Chul Hyoung Lyoo, Renaud La Joie, Gil D. Rabinovici, Rik Ossenkoppele, Pedro Rosa‐Neto, Oskar Hansson
Abstract
Abstract Purpose This study aims to determine whether comparable target regions of interest (ROIs) and cut-offs can be used across [ 18 F]flortaucipir, [ 18 F]RO948, and [ 18 F]MK6240 tau positron emission tomography (PET) tracers for differential diagnosis of Alzheimer’s disease (AD) dementia vs either cognitively unimpaired (CU) individuals or non-AD neurodegenerative diseases. Methods A total of 1755 participants underwent tau PET using either [ 18 F]flortaucipir ( n = 975), [ 18 F]RO948 ( n = 493), or [ 18 F]MK6240 ( n = 287). SUVR values were calculated across four theory-driven ROIs and several tracer-specific data-driven (hierarchical clustering) regions of interest (ROIs). Diagnostic performance and cut-offs for ROIs were determined using receiver operating characteristic analyses and the Youden index, respectively. Results Comparable diagnostic performance (area under the receiver operating characteristic curve [AUC]) was observed between theory- and data-driven ROIs. The theory-defined temporal meta-ROI generally performed very well for all three tracers (AUCs: 0.926–0.996). An SUVR value of approximately 1.35 was a common threshold when using this ROI. Conclusion The temporal meta-ROI can be used for differential diagnosis of dementia patients with [ 18 F]flortaucipir, [ 18 F]RO948, and [ 18 F]MK6240 tau PET with high accuracy, and that using very similar cut-offs of around 1.35 SUVR. This ROI/SUVR cut-off can also be applied across tracers to define tau positivity.