Mapping the Synaptome in Neurodegeneration: Emerging Clinical Applications of SV2A PET Imaging.

Synaptic loss is a core pathological feature of neurodegenerative disorders and closely relates to cognitive and functional decline. Positron emission tomography (PET) targeting synaptic vesicle glycoprotein 2A (SV2A) has recently emerged as a promising tool for the indirect assessment of presynaptic alterations in the living human brain. This leading article discusses the evolving clinical landscape of SV2A PET across the neurodegenerative spectrum, emphasizing its translational trajectory and emerging applications. Current evidence spans Alzheimer's disease (AD), other dementias, movement disorders, Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). The literature is currently dominated by PET with [11C]UCB-J, while [18F]-labeled tracers, particularly [18F]SynVesT-1, are expanding clinical feasibility through longer half-life and broader distribution potential. Across disorders, PET consistently detected SV2A reductions that frequently correlated with cognition, disease severity, and complementary biomarkers, including amyloid, tau, glucose metabolism, and dopaminergic imaging. Although the field remains limited by small cohorts, heterogeneous quantification strategies, and incomplete longitudinal validation, SV2A PET is rapidly evolving into a promising translational tool for studying synaptopathies and monitoring disease progression.