Correlation between 18F⁃S16 PET imaging and glucose metabolism pattern in behavioral variant frontotemporal dementia

Abstract

Objective To investigate the characteristics of 18F⁃S16 PET imaging in brain tissue of patients with behavioral variant frontotemporal dementia (bvFTD) and the correlation between tau protein deposition and glucose metabolism pattern. Methods A total of 12 bvFTD patients and 10 controls with normal cognitive function treated in Tianjin Medical University General Hospital from January 2020 to October 2021 were included, and all of them underwent 18F⁃S16 PET and 18F⁃FDG PET. The difference of 18F⁃S16 and 18F⁃FDG uptake between bvFTD group and control group was compared by voxel⁃based analysis (VBA). The 18F⁃S16 and 18F⁃FDG standard uptake value rate (SUVR) of 2 groups were compared by semi⁃quantitative analysis. The 18F⁃S16 uptake rate of 2 groups was observed by visual analysis. Pearson correlation analysis was used to explore the whole⁃brain spatial correlation of 18F⁃S16 and 18F⁃FDG tracers and the correlation of uptake levels in each region of interest (ROI). Results VBA method showed the uptake of 18F⁃S16 increased in the right superior frontal gyrus, bilateral middle frontal gyrus and inferior frontal gyrus, bilateral anterior central gyrus, bilateral middle temporal gyrus, right inferior temporal gyrus, right posterior central gyrus and left inferior parietal lobule in bvFTD patients (P＜0.01, for all, FEW correction, pixel threshold=50). The uptake of 18F⁃FDG in bilateral superior frontal gyrus, bilateral middle frontal gyrus, right inferior frontal gyrus, bilateral anterior cingulate gyrus and right insula decreased in bvFTD patients (P=0.000, for all, FWE correction, pixel threshold=50). The overlaps were mainly located in the right superior frontal gyrus, bilateral middle frontal gyrus and right inferior frontal gyrus. Semi⁃quantitative analysis showed the SUVR value of tau protein in bilateral frontal lobe (P=0.000), parietal lobe (P=0.015) and precuneus (P=0.000) in bvFTD group was higher than that in control group, and the SUVR value of glucose in bilateral frontal lobe was lower than that in control group (P=0.002). Pearson correlation analysis showed the whole⁃brain spatial correlation between 18F⁃S16 and 18F⁃FDG was weak in bvFTD patients (r=0.050, P=0.000). In bvFTD patients, only bilateral frontal tau SUVR was negatively correlated with glucose SUVR (r=⁃0.702, P=0.011). Visual analysis of 18F⁃S16 PET showed increased uptake in bilateral frontal, parietal, precuneus, and hippocampus in bvFTD patients. Conclusions 18F⁃S16 PET can reflect the characteristic of tau protein deposition and its correlation with glucose metabolic pattern in bvFTD patients.

Keywords

• frontotemporal dementia
• tau proteins
• deoxyglucose
• positron ⁃ emission tomography