Abstracts

Rationale: Non invasive approach to define epileptogenic focus in tuberous sclerosis complex (TSC) is challenging. The purpose of this study is to evaluate if standardized uptake value (SUV) calculation in FDG-PET can detect epileptogenic tissue in TSC. Methods: Six patients (mean age, 2.7 y) who underwent tuberectomy between February 2009 and September 2011, were selected. All patients had preoperative FDG-PET and MRI. Epileptogenic tubers (n =13) were defined by multimodality evaluation using EEG, Magnetoencephalogram, and intraoperative electrocorticography and these were compared with nonepileptogenic tubers (n =100). All tubers were segmented into three regions for calculation of SUV: within the tubers, 2 mm outer margin of tubers, and 4 mm outer margin of tubersusing AFNI (Analysis of Functional NeuroImaging). Six parameters were analyzed: intra-lesion SUV; SUV at the 2 mm and 4 mm margins; combined SUV of the 2 mm and 4 mm margins; combined SUV of the intra-lesion and the 2 mm margin; and a combined SUV of all three regions. A Man-Whitney test was performed to compare the differences in these six parameters between the epileptogenic and non-epileptogenic tubers. We also classified tubers in Frontal, Parietal, Temporal, and Occipital lobe and analysis was made in each lobe. Results: In all six parameters, epileptogenic tubers in temporal lobe showed significantly lower mean SUV compared to non-epileptogenic tubers (p < 0.003). No statistical significance was obtained in the epileptogenic tubers found in the other lobes. Conclusions: SUV analysis of FDG PET showed significantly lower value in only temporal lobe epileptogenic tissues.