[¹⁸F]FDG PET/MRI in Pediatric Focal Epilepsies

Area of Science:

• Neurology
• Radiology
• Nuclear Medicine

Background:

• Pediatric focal epilepsy surgery requires precise localization of the epileptogenic zone (EZ).
• Magnetic Resonance Imaging (MRI) alone can be inconclusive or negative in identifying the EZ in pediatric cases.
• Fluorodeoxyglucose Positron Emission Tomography/MRI ([18F]FDG PET/MRI) offers combined metabolic and structural information.

Purpose of the Study:

• To evaluate the efficacy of [18F]FDG PET/MRI in improving presurgical lesion detection compared to MRI alone in pediatric focal epilepsy.
• To analyze the impact of [18F]FDG PET/MRI on surgical outcomes and the presurgical evaluation pipeline.

Main Methods:

• Retrospective analysis of pediatric patients (≤18 years) with focal epilepsy undergoing [18F]FDG PET/MRI (Jan 2017-Oct 2021).
• Inclusion criteria: negative or inconclusive MRI results prior to PET/MRI.
• Phased data analysis: prior MRI review, masked PET/MRI review, joint assessment, and verification against electroclinical hypothesis (EEG, SEEG, histology).

Main Results:

• 79 pediatric patients (mean age 9.5 years) with drug-resistant epilepsy were included.
• [18F]FDG PET/MRI identified lesions in 58% of patients with concordant PET-positive/MRI-positive findings and detected metabolic alterations in 89%.
• Surgical intervention in 29 patients resulted in 76% achieving Engel Class IA seizure-free outcomes.

Conclusions:

• [18F]FDG PET/MRI significantly enhances presurgical lesion detection and diagnostic accuracy in pediatric focal epilepsy, particularly in MRI-negative/inconclusive cases.
• The combined imaging modality provides crucial prognostic value, improving the precision of presurgical evaluations.
• [18F]FDG PET/MRI effectively guides clinical decision-making for pediatric epilepsy surgery, leading to favorable seizure control outcomes.