Semiquantitative analysis of cerebral [¹⁸F]FDG-PET uptake in pediatric patients

Glycolytic metabolism in the brain of pediatric patients, imaged with [¹⁸F]  fluorodeoxyglucose-positron emission tomography (FDG-PET) is incompletely characterized.

The purpose of the current study was to characterize [¹⁸F]FDG-PET brain uptake in a large sample of pediatric patients with non-central nervous system diseases as an alternative to healthy subjects to evaluate changes at different pediatric ages.

Seven hundred ninety-five [¹⁸F]FDG-PET examinations from children < 18 years of age without central nervous system diseases were included. Each brain image was spatially normalized, and the standardized uptake value (SUV) was obtained. The SUV and the SUV relative to different pseudo-references were explored as a function of age.

At all evaluated ages, the occipital lobe showed the highest [¹⁸F]FDG uptake (0.27 ± 0.04 SUV/year), while the parietal lobe and brainstem had the lowest uptake (0.17 ± 0.02 SUV/year, for both regions). An increase [¹⁸F]FDG uptake was found for all brain regions until 12 years old, while no significant uptake differences were found between ages 13 (SUV = 5.39) to 17 years old (SUV = 5.52) (P < 0.0001 for the whole brain). A sex dependence was found in the SUVmean for the whole brain during adolescence (SUV 5.04-5.25 for males, 5.68-5.74 for females, P = 0.0264). Asymmetries in [¹⁸F]FDG uptake were found in the temporal and central regions during infancy.

Brain glycolytic metabolism of [¹⁸F]FDG, measured through the SUVmean, increased with age until early adolescence (< 13 years old), showing differences across brain regions. Age, sex, and brain region influence [¹⁸F]FDG uptake, with significant hemispheric asymmetries for temporal and central regions.