Tau positron emission tomography in tauopathies: A narrative review

Abstract

Aggregation of misfolded tau in the brain is a major pathological feature common in various neurodegenerative disorders known as tauopathies, including Alzheimer’s disease, progressive supranuclear palsy, corticobasal syndrome, and dementia with Lewy bodies. Tauopathies are collection of diseases with varied overlapping symptoms and complicated manifestations. Consequently, it is crucial to be able to assess tau deposits <i>in vivo</i>. Over the past decade, tau-specific radioligands for positron emission tomography (PET) have been developed and tested, including first-generation compounds (e.g., ¹⁸F-THK5317, ¹⁸F-THK5351, ¹⁸F-AV1451, and ¹¹C-PBB3) and second-generation compounds (¹⁸F-MK-6240, ¹⁸F-RO-948, and ¹⁸F-PI-2620). With the recent advances of tau PET tracers, assessing the pattern of tau deposition <i>in vivo</i> is possible. These methods will allow accurate diagnosis of tauopathies and monitoring of disease progression. In this mini review, we summarize current findings from studies using tau PET tracers regarding neuropathological characteristics, clinical implications, and potential applications of tau PET. We also discuss methodological considerations for appropriate use of these technologies and discuss what has been learned from these findings.