Prediction of Amyloid Positivity in Lewy Body Disease Using Early-Phase 18 F-FP-CIT PET Images

Area of Science:

• Neurology
• Nuclear Medicine
• Neuroimaging

Background:

• Lewy body disease (LBD) diagnosis can be challenging, often requiring differentiation from Alzheimer's disease.
• Beta-amyloid (Aβ) deposition is a key pathological hallmark in some neurodegenerative diseases.
• 18F-FP-CIT PET imaging assesses presynaptic dopaminergic function, but its utility in predicting Aβ status in LBD is less understood.

Purpose of the Study:

• To investigate if early-phase 18F-FP-CIT PET imaging can predict Aβ positivity in patients with LBD.
• To explore the relationship between regional cerebral perfusion, Aβ load, and cognitive decline in LBD.

Main Methods:

• 132 patients with LBD underwent dual-phase 18F-FP-CIT PET and 18F-FBB PET scans.
• Patients were categorized into Aβ-positive (n=69) and Aβ-negative (n=63) groups.
• Linear discriminant analysis (LDA) predicted Aβ positivity using standard uptake value ratios (SUVRs) from early-phase 18F-FP-CIT PET.

Main Results:

• No significant differences in demographics or motor function between Aβ-positive and Aβ-negative groups.
• Aβ-positive group showed reduced uptake in parietal, precuneus, temporal, and cingulate cortices, and increased uptake in the caudate on early-phase 18F-FP-CIT PET.
• LDA models identified inferior parietal cortex and caudate SUVRs as optimal predictors of Aβ status.
• Greater Aβ burden correlated with faster Mini-Mental State Examination (MMSE) decline, partially mediated by inferior parietal hypoperfusion.

Conclusions:

• Regional cerebral perfusion alterations on early-phase 18F-FP-CIT PET may serve as a biomarker for predicting Aβ deposition in LBD.
• These perfusion changes could offer insights into the pathophysiology linking Aβ, perfusion deficits, and cognitive decline in LBD.