The added value of [18F]-fluoro-D-deoxyglucose positron emission tomography in screening for temporal lobe epilepsy surgery.
OBJECTIVE
[18F]-Fluoro-d-deoxyglucose positron emission tomography (FDG-PET) is an expensive, invasive, and not widely available technique used in the presurgical evaluation of temporal lobe epilepsy. We assessed its added value to the decision-making process in relation to other commonly used tests.


METHODS
In a retrospective study of a large series of consecutive patients referred to the national Dutch epilepsy surgery program between 1996 and 2002, the contribution of FDG-PET, magnetic resonance imaging (MRI), and video-electroencephalogram (video-EEG) monitoring findings, alone or in combination, to the decision whether to perform surgery was investigated. The impact of FDG-PET was quantified by comparing documented decisions concerning surgery before and after FDG-PET results.


RESULTS
Of 469 included patients, 110 (23%) underwent FDG-PET. In 78 of these patients (71%), FDG-PET findings led clinicians to change the decision they had made based on MRI and video-EEG monitoring findings. In 17% of all referred patients, the decision regarding surgical candidacy was based on FDG-PET findings. FDG-PET was most useful when previous MRI results were normal (p < 0.0001) or did not show unilateral temporal abnormalities (p < 0.0001), or when ictal EEG results were not consistent with MRI findings (p < 0.0001) or videotaped seizure semiology (p = 0.027). The positive and negative predictive values for MRI and video-EEG monitoring, which ranged from 0.48 to 0.67, were improved to 0.62 to 0.86 in combination with FDG-PET.


CONCLUSIONS
In patients referred for TLE surgery, FDG-PET findings can form the basis for deciding whether a patient is eligible for surgery, and especially when MRI or video-EEG monitoring are nonlocalizing.
Uijl
Sabine G
SG
Department of Clinical Neurophysiology, Rudolf Magnus Institute of Neuroscience and University Medical Center Utrecht, UMC Utrecht, Utrecht, The Netherlands.
Leijten
Frans S S
FS
Arends
Johan B A M
JB
Parra
Jaime
J
van Huffelen
Alexander C
AC
Moons
Karel G M
KG
D004833:Epilepsy, Temporal Lobe / Q000601:surgery*; D019788:Fluorodeoxyglucose F18; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D012189:Retrospective Studies
D019788:Fluorodeoxyglucose F18