Validation and test-retest repeatability performance of parametric methods for [¹¹C]UCB-J PET.

Area of Science:

• Neuroimaging
• Radiochemistry
• Nuclear Medicine

Background:

• [11C]UCB-J is a positron emission tomography (PET) radioligand targeting presynaptic vesicle glycoprotein 2A.
• PET imaging with [11C]UCB-J shows potential as an in vivo biomarker for synaptic integrity.

Purpose of the Study:

• To assess the quantitative accuracy of various parametric methods for dynamic [11C]UCB-J PET studies.
• To evaluate the 28-day test-retest repeatability (TRT) of these methods in Alzheimer's disease (AD) patients and healthy controls (HC).

Main Methods:

• Eight HC and seven AD patients underwent two dynamic [11C]UCB-J PET scans over 28 days.
• Plasma-input and reference-region based parametric methods were employed, comparing outcomes with non-linear regression (NLR) and assessing TRT.

Main Results:

• Spectral analysis (SA) and Logan graphical analysis demonstrated high correlation with NLR estimates.
• Receptor parametric mapping (RPM), SRTM2, and RLogan showed good correlation with plasma-input derived values.
• MRTM1 exhibited the best correspondence among MRTM methods.

Conclusions:

• Spectral analysis (SA) is recommended as the optimal plasma-input method for accurate [11C]UCB-J quantification.
• Simplified reference tissue model 2 (SRTM2) is the preferred reference tissue method for reliable parametric imaging.