To perform a systematic review and individual participant data meta-analysis, to determine the efficacy and safety of MR-guided laser interstitial thermoablative therapy (MRgLITT) for drug-resistant epilepsy. Our secondary objective was to determine the effect of patient's age and etiology on the success of the procedure.

We included cohort studies of consecutive participants undergoing MRgLITT that reported outcome. The outcome was defined as the time to seizure recurrence. We performed title, abstract and full text screening independently and in duplicate. We resolved disagreements through discussion. To identify independent predictors of outcome following MRgLITT, we performed univariate Cox proportional hazards regression analysis to identify variables with a P value of less than 0.2 to be entered into a multivariate Cox proportional hazards regression model.

Of 4308 citations, 12 articles reporting on 92 participants were eligible. The median duration of follow-up was 12 (range 1–38.5) months and 53 (57.6%) participants were seizure-free (Engel class 1) at follow-up. The mean duration of seizure freedom following MRgLITT was 19.4 months (95% CI, 15.0–23.8). Patient age and history of prior surgery were not predictors of outcome on Cox regression univariate analysis. We identified a difference in efficacy dependent on etiology but we were underpowered to conclude a statistically significant difference. Hypothalamic hamartoma had better seizure freedom than MTS/MTA, and both were superior to FCD, although this was not statistically significant. There was no procedure-related mortality, but morbidity was experienced in 14 (15.2%) of participants mainly comprising probe/device malfunction, unexpected neurological deficit, hemorrhage, or cerebral edema.

The best available evidence suggests that MRgLITT is a variably effective procedure dependent on etiology, is associated with reduced length of stay postoperatively and has a moderate morbidity profile. It should be considered first line treatment in drug-resistant epilepsy due to hypothalamic hamartoma.