New Targets for Positron Emission Tomography Imaging in Parkinson´s Disease

In recent years, the neuroimaging biomarkers for Parkinson's disease (PD) has advanced rapidly, targeting to the key pathological mechanisms such as α-synuclein (α-syn) aggregation, neuroinflammation, mitochondrial dysfunction and brain clearance. This review summarized the novel imaging targets and their clinical practice in human studies. The presynaptic dopamine transporters and ¹⁸F-Fluorodeoxyglucose positron emission tomography (PET) have been characterized as established biomarkers in PD. Furthermore, as the key pathogenic protein in PD, α-syn aggregation forming Lewy bodies could drive the neuronal degeneration, making the α-syn-targeted PET imaging a critical focus in PD research. Other co-pathologies, including amyloid-β and tau protein, were also concluded for their clinical implications in PD. Additionally, the PET imaging targets for neuroinflammatory mechanisms, including mitochondrial dysfunction, microglial and astrocyte activation, hold promise for further investigation. Finally, the radiotracers detecting disruptions of blood-brain barrier and glymphatic system would also represent as therapeutic opportunities. In conclusion, the vigorous development of novel imaging biomarkers in PD will refine the diagnostic frameworks, promoting for the future disease-modifying therapies.