Navigating the brain: the role of 18F-FDG PET/CT in pinpointing epileptic foci

Background Epilepsy is a chronic neurological condition marked by recurring seizures. The 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) technique is thought to be useful for determining the location of epilepsy. However, its ability to detect the epileptic zone in patients with drug-resistant epilepsy (DRE) remains unclear. Therefore, we aimed to determine the role of 18F-FDG PET/CT in localization of temporal and extratemporal epilepsies in patients with refractory epilepsy. Methods This is a cross-sectional study examining patients with refractory epilepsy who were admitted to Masih Daneshvari Hospital, Iran. This study includes patients with refractory epilepsy who had normal brain magnetic resonance imaging (MRI) results. The seizure focus was indicated by two professional neurologists using a video-electroencephalography monitoring (VEM). All patients received an intravenous injection of FDG at a dosage of 4.6 MBq/kg. The patient's records and FDG PET/CT results were then checked, and if they were congruent, the patient would undergo surgery and resection of the epileptic region. The data were reported using descriptive statistics. We also used Cohen's kappa coefficient (k) test to assess interrater agreement between temporal lobe localization and congruency with FDG-PET data. Results Our investigation revealed that 65.60% of seizures occurred in temporal lobe, with 67.96% exhibiting congruent PET results. Furthermore, 25.4% had a focus in frontal lobe, while only 12.5% showed congruent PET results. Temporal lobe was the focus of the majority (92.1%) of congruent PET data, as well as 36.3% of partially congruent PET data and 42.3% of incongruent PET data. PET scans revealed that 28.1% were negative, with 47.7% clinically focused in temporal lobe, 38.6% in the frontal lobe, and 13.6% only partially localized. In addition, the interrater agreement for seizure focus localization in temporal lobe was 0.71, indicating substantial agreement. Conclusion FDG PET/CT was shown to be an acceptable technique for identifying DRE, namely, temporal lobe epilepsy. The gold standard methods can provide more accurate epilepsy zone localization, resulting in better FDG PET/CT congruency.