Analysis of hypermetabolic lesions on 18F-FDG PET/CT scan in pediatric patients with epilepsy

Objective To investigate the characteristics of metabolic foci on 18F-fluorodeoxyglucose (FDG) PET/CT scan in pediatric patients with epilepsy. Methods Twenty-three pediatric patients (15 males, 8 females, age range: 0.5-13.3 years) with epilepsy were retrospectively reviewed from March 2014 to December 2016. All patients underwent 18F-FDG PET/CT and metabolic foci were found. The visual method and semi-quantitative analysis were used to analyze images. Fourteen of them underwent surgery and were followed up for 3-24 months. Results Glucose hypermetabolism were observed most frequently in the frontal and parietal lobes, with or without surrounding/remote hypometabolism. On the day of PET/CT imaging, 8 patients had no seizures, 14 patients had seizures, and 1 patient was uncertain. The sites of resection were consistent with the regions of hypermetabolism in 9 patients, among whom the pathological results showed 8 cortical malformations and 1 Rasmussen′s syndrome. Follow-up results for the above 9 patients showed that there was 7 Engel class Ⅰ patients and 2 Engel class Ⅲ patients. Conclusion The hypermetabolism may mostly appear in the frontal and parietal lobes of pediatric patients with epilepsy, and malformations of cortical development seem to be the most common pathology results. Key words: Epilepsy; Child; Positron-emission tomography; Tomography, X-ray computed; Deoxyglucose