Using PET with 18F-AV-45 (florbetapir) to quantify brain amyloid load in a clinical environment

Area of Science:

• Neurology
• Radiology
• Biomarker Discovery

Background:

• Alzheimer's disease (AD) diagnosis relies on identifying amyloid-beta plaques.
• Positron emission tomography (PET) imaging is a key tool for visualizing brain amyloid load.
• Florbetapir (18F-AV-45) is a radiotracer used for PET imaging of amyloid.

Purpose of the Study:

• To evaluate the feasibility of using florbetapir PET in routine clinical settings.
• To differentiate patients with mild to moderate AD and mild cognitive impairment (MCI) from healthy controls (HC).

Main Methods:

• 46 subjects (13 AD, 12 MCI, 21 HC) underwent florbetapir PET scans.
• Scans were assessed visually and quantitatively using Standardized Uptake Value Ratio (SUVr).
• Cerebellum was used as the reference region for SUVr calculations.

Main Results:

• Higher cortical SUVr values were observed in AD patients compared to HC (p=0.0001).
• MCI subjects showed increased florbetapir uptake in the posterior cingulate cortex versus HC (p=0.03).
• Quantitative SUVr demonstrated 92.3% sensitivity and 90.5% specificity for AD detection.

Conclusions:

• Florbetapir PET is a safe and suitable biomarker for routine clinical use in AD diagnosis.
• Quantitative analysis offers superior diagnostic accuracy compared to visual assessment.
• Further training and automated tools can enhance the specificity of visual PET scan interpretation.