(18)F-FDG PET in localization of frontal lobe epilepsy: comparison of visual and SPM analysis.
The sensitivity of (18)F-FDG PET to localize epileptogenic zones in frontal lobe epilepsy was evaluated by both visual assessment and statistical parametric mapping (SPM).


METHODS
Twenty-nine patients with frontal lobe epilepsy were examined. All patients showed good outcome after surgical resection (Engel class I or II). On pathologic examination, 22 patients had cortical dysplasia, 4 had tumors, 1 had cortical scars, and 2 had an old infarct. Hypometabolic lesions were found on (18)F-FDG PET images by both visual assessment and SPM analysis. On SPM analysis, the cutoff threshold was varied and sensitivity to find epileptogenic zones was compared.


RESULTS
MRI showed structural lesions in 15 patients and normal findings in 14. (18)F-FDG PET correctly localized the epileptogenic zones in 16 patients (55%) by visual assessment. The sensitivity of (18)F-FDG PET was 36% in patients without structural lesions on MRI and 73% in patients with structural lesions. On SPM analysis, using an uncorrected probability value of 0.005 as the threshold, the sensitivity of SPM analysis was 66%, which was not statistically different from the sensitivity of visual assessment. The sensitivity decreased according to the decrease in probability value.


CONCLUSIONS
(18)F-FDG PET was sensitive in localizing epileptogenic zones by revealing hypometabolic areas in nonlesional patients with frontal lobe epilepsy as well as in lesional patients. SPM analysis showed a comparable sensitivity to visual assessment and could be used as an aid in diagnosing epileptogenic zones in frontal lobe epilepsy.
Kim
Yu Kyeong
YK
Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea.
Lee
Dong Soo
DS
Lee
Sang Kun
SK
Chung
Chun Kee
CK
Chung
June-Key
JK
Lee
Myung Chul
MC
D000328:Adult; D016022:Case-Control Studies; D017034:Epilepsy, Frontal Lobe / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015233:Models, Statistical; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18