11C-UCB-J ((R)-1-((3-(11C-methyl-11C)pyridin-4-yl)methyl)-4-(3,4,5-trifluorophenyl)pyrrolidin-2-one) is a PET tracer for synaptic vesicle glycoprotein 2A, which may be a marker of synaptic density. To simplify the scan protocol, SUV ratios (SUVRs) were compared with model-based nondisplaceable binding potential (BPND) to select the optimal time window in healthy and neuropsychiatric subjects. Methods: In total, 141 scans were acquired for 90 min. Arterial blood sampling and metabolite analysis were conducted. SUVR-1 (centrum semiovale reference region) was computed for six 30-min windows and compared with 1-tissue-compartment model BPND Simulations were performed to assess the time dependency of SUVR-1. Results: Greater correlation and less bias were observed for SUVR-1 at later time windows for all subjects. Simulations showed that the agreement between SUVR-1 and BPND is time-dependent. Conclusion: The 60- to 90-min period provided the best match between SUVR-1 and BPND (-1% ± 7%); thus, a short scan is sufficient for accurate quantification of 11C-UCB-J-specific binding.
Keywords: PET; SUVR; SV2A; brain imaging; synaptic vesicle protein 2A.
© 2021 by the Society of Nuclear Medicine and Molecular Imaging.