PROSPECTIVE LOCALIZATION OF EPILEPTOGENIC FOCI - COMPARISON OF PET AND SPECT WITH SITE OF SURGERY AND CLINICAL OUTCOME

PURPOSE: To correlate prospective imaging findings in patients with in tractable partial epilepsy with site of surgery and clinical outcome. MATERIALS AND METHODS: Thirty-five patients (25 male, 10 female) under went positron emission tomography (PET; n = 25), interictal single pho ton emission computed tomography (SPECT; n = 33), or postictal SPECT ( n = 23) for localization of epileptogenic foci. The standard of refere nce was site of surgery. RESULTS: Sensitivity was 60%, 61%, and 52%; p ositive predictive value was 83%, 71%, and 55%; and localization was i ncorrect in 12% (three of 25 cases), 24% (eight of 33 cases), and 43% (10 of 23 cases) in PET, interictal SPECT, and postictal SPECT, respec tively. There was no statistically significant difference in localizat ion capabilities in a comparison of interictal SPECT and PET (correct localization, P = .999; incorrect localization, P = .625). There was a trend toward higher incorrect localization with interictal SPECT. CON CLUSION: Postictal SPECT has low sensitivity and a high incorrect loca lization rate and should not be performed in these patients. Intericta l SPECT with 6-8-mm full-width at half-maximum is an alternative to PE T. However, the trend toward higher false-localization rates must be t aken into consideration.