Seizure Outcome After Surgery for Refractory Epilepsy Diagnosed by 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/MRI): A Systematic Review and Meta-Analysis

-OBJECTIVE: When magnetic resonance imaging (MRI) fails to detect an un-derlying epileptogenic lesion, the odds of a good outcome after epilepsy surgery are significantly lower (20%-65% compared with 60%-90% if a lesion is detected). We investigated the possible effects of introducing hybrid 18F-fluo-rodeoxyglucose positron emission tomography (18F-FDG PET)/MRI into the de-cision algorithm for patients with lesioned and nonlesioned drug-resistant epilepsy. -METHODS: Three databases were searched from January 1990 to October 2022. We registered the protocol with International Platform of Registered Systematic Review and Meta-analysis Protocols. Studies in which 18F-FDG PET/ MRI was conducted with double dagger 12 months of postsurgical follow-up in patients with refractory epilepsy. Random-effects meta-analysis was used to calculate the proportion of patients with good outcomes. Metaregression was used to investigate sources of heterogeneity. -RESULTS: We identified 8105 studies, of which 23 (1292 patients in total) were included. The overall good postoperative outcome rate was 71% (95% confi-dence interval 63.6-74.9). Good outcome was associated with the location of the refractory epileptic lesion (temporal lobe or extratemporal; risk ratio 1.27 [95% confidence interval 1.01-1.52], P [ 0.009); Length of postoperative follow-up double dagger 40 months included in the same study accounted for 0.6% of the observed heterogeneity. -CONCLUSIONS: Seventy-one percent of patients with refractory epilepsy and 18F-FDG PET/MRI epileptogenic lesion features had a good outcome of epilepsy after surgery. Our findings can be incorporated into routine preoperative con-sultations and emphasize the importance of the complete resection of the temporal lobe epileptogenic zone for 18F-FDG PET/MRI detection when safe and feasible.