Radiology, Vol 199, 375-380, Copyright © 1996 by Radiological Society of North America
Prospective localization of epileptogenic foci: comparison of PET and SPECT with site of surgery and clinical outcome
ST Mastin, WE Drane, RL Gilmore, WR Helveston, RG Quisling, SN Roper, EA Eikman and SR Browd
Department of Radiology, University of Florida, College of Medicine, Gainesville, Fl 32610, USA.
PURPOSE: To correlate prospective imaging findings in patients with
intractable partial epilepsy with site of surgery and clinical outcome.
MATERIALS AND METHODS: Thirty-five patients (25 male, 10 female) underwent
positron emission tomography (PET; n=25), interictal single photon emission
computed tomography (SPECT; n=33), or postictal SPECT (n=23) for
localization of epileptogenic foci. The standard of reference was site of
surgery. RESULTS: Sensitivity was 60%, 61%, and 52%; positive predictive
value was 83%, 71%, and 55%; and localization was incorrect in 12% (three
of 25 cases), 24% (eight of 33 cases), and 43% (10 of 23 cases) in PET,
interictal SPECT, and postictal SPECT, respectively. There was no
statistically significant difference in localization 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. CONCLUSION: Postictal SPECT has low
sensitivity and a high incorrect localization rate and should not be
performed in these patients. Interictal SPECT with 6-8-mm full-width at
half-maximum is an alternative to PET. However, the trend toward higher
false-localization rates must be taken into consideration.
