Interstitial Thermal Therapy in Mesial Temporal Lobe Epilepsy

Importance Laser interstitial thermal therapy (LITT) is a surgical tool used to ablate epileptic foci and brain tumors. Understanding clinical and procedural outcomes of LITT for mesial temporal lobe epilepsy (MTLE) is relevant to clinicians and patients. Objective To describe seizure outcomes, procedural outcomes, and safety data of MTLE LITT. Design, Setting, and Participants Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN) is a prospective multicenter registry with up to 5 years of follow-up lasting from October 2015 to March 2023 at LAANTERN epilepsy sites, which are all level IV National Association of Epilepsy Centers in the US. Adult and pediatric LAANTERN enrollees undergoing LITT for drug-resistant MTLE with at least 6 months of follow-up were included. Those with epilepsy related to a malignant lesion were excluded. Intervention LITT for drug-resistant MTLE. Main Outcomes and Measures Demographic, epilepsy, and seizure characteristics; procedural data; postsurgical seizure outcomes; safety data; and quality of life (QOL) scores were prospectively collected. Results Fifteen centers enrolled 145 patients (73 [50.3%] female) with MTLE undergoing LITT, with 77 reaching 2-year follow-up. The mean (SD) age was 39.2 (15.4) years at time of LITT with 14 of 145 in the pediatric range (younger than 22 years). The 2 most common etiologies were mesial temporal sclerosis (n = 74) and unknown etiology or magnetic resonance imaging normal (n = 31). Mean (SD) ablation volume was 28.2 (29.8) mL. Mean (SD) surgery duration was 4.3 (2.1) hours, and mean (SD) blood loss was 22 (17.6) mL. Median (IQR) length of stay was 1 (1-3) day, and 33 patients (23%) had no intensive care unit stay postprocedure. Median (IQR) intensive care unit time was 22 (19.2-28.8) hours. Mean (SD) discharge head pain score was 2.1 (2.6) on a 0-10 scale. Most patients (n = 140 [96.6%]) were discharged home. Two-year seizure outcomes were 45 of 77 (58.4%) and 44 of 77 (57.2%) for Engel 1 and International League Against Epilepsy 1/2, respectively. No clinical characteristics were associated with seizure outcome. Adverse events were seen in 24 patients (16.5%), most being mild and transient. Pediatric seizure outcomes were similar to adult outcomes. One-third of patients stopped or decreased their antiseizure medicines. Improvements in QOL scores were seen at almost all time points assessed. Conclusions In the largest prospective multicenter MTLE LITT cohort, LITT was found to be well tolerated with clinically meaningful seizure outcomes and QOL improvements. These findings indicate that LITT may be considered as a treatment option for drug-resistant MTLE.