PET in presurgical evaluation of epilepsy.
Background: Today, at Rikshospitalet PET medical center, FDG is used as a tracer in the PET investigations during the presurgical evaluation of patients with epilepsy. The purpose of this paper is to see if FGD-PET gives additional information compared with EEG and MR. Another purpose was to find out whether there is a need for new ligands, and which ones.
Material and methods: All epilepsy order forms to FDG-PET at Rikshopitalet, during 2007-2009, were reviewed. The result from the PET-investigation were compared with the results of EEG and MR. The order forms were categorized into three groups, according to whether FDG-PET confirmed, was more or less specific, in comparison to EEG and MR. There was performed a literature search for review articles regarding FDG, and also for other possible tracers.
Results: It was performed 336 PET-cerebrum and 68 order forms matched the inclusion-criterias for our target group. 25 (36,8%) investigations confirmed EEG and MR. 29 (42,6%) investigations was less specific than EEG and MR. 14 (20,6%) was more specific than EEG and MR. The literature search shows that FDG-PET is a good diagnostic tool regarding lateralizing temporal lobe epilepsy, but less sufficient in discovering medial temporal lobe epilepsy.
Conclusion: FDG-PET gives additional information in 20,6%, but it is not possible to make a conclusion on which subgroups of epilepsy this number represents. The review articles show that FDG-PET gives additional information where MR and/or EEG are not able to localize a focus. There is a need for new ligands, because FDG rarely discover mesial temporal lobe epilepsy. Flumazenil complement the qualities of FDG.