Abstracts

Rationale: Laser interstitial thermal therapy (LITT) is a minimally invasive surgical tool for the treatment of drug resistant epilepsy. LAANTERN is a multicenter registry that collects data on patients using the NeuroBlate system. Here we selectively analyze epilepsy LITT procedures from LAANTERN and assess patient outcomes, clinical characteristics, and procedural data. Methods: LAANTERN is designed to prospectively capture data using the NeuroBlate system for standard of care procedures. Patients undergoing LITT were consented for enrollment into the LAANTERN registry. Data are collected regarding patient demographics, procedural data, adverse events, and outcomes from 4 centers. Results: LAANTERN is designed to prospectively capture data using the NeuroBlate system for standard of care procedures. Patients undergoing LITT were consented for enrollment into the LAANTERN registry. Data are collected regarding patient demographics, procedural data, adverse events, and outcomes from 4 centers. Results: Twenty five epilepsy subjects are enrolled at four centers with an average age of 37.4 (range 10-72). Temporal lobe epilepsy (TLE) is the most common epilepsy localization (18). Other localizations include frontal lobe (2), parietal lobe (1), occipital lobe (1), insula (3), and paraventricular nodular heterotopia (2). Some patients had multiple localizations ablated. Six patients had previous depth electrode monitoring. All patients noted resection as an alternate therapy with 16 noting the reason for LITT was preference of a minimally invasive therapy. Twenty patients had one lesion while four patients had two lesions. The median number of lesions ablated was one (range 1-3). Median blood loss was 0 mL (range 0-50 mL). The median number of burr holes was one (range 1-3) with 21/28 (75%) having one trajectory, 6/28 (21.4%) having two trajectories, and 1/28 (3.6%) having four trajectories. 22/27 (81.5%) ablations utilized the full fire probe while 5/27 (18.5%) utilized the side fire probe. Lastly, 19/30 (63.3%) ablations were new targets while 11/30 (36.7%) were residual/repeat targets. Nineteen patients reached six month follow up with seven being seizure free. 13 patients reached one year follow up with five being seizure free. All seizure free patients had temporal lobe ablations. When TLE patients are selectively analyzed, 54% (7/13) and 50% (5/10) were seizure free at six and twelve months respectively. Of interest, 1/4 using the side fire probe and 3/6 with previous intracranial electrode evaluation are seizure free at last visit. Three patients had five adverse events. One patient had two seizure clusters and one episode of hyponatremia not related to the ablation or surgery, all of which resolved. This patient was electively admitted for seizure characterization and found to have a non-epileptic explanation for his seizure clusters. The second patient had a 3mm right convexity subdural hematoma related to the surgery but not the ablation. A third patient experienced a headache that resolved on the third postoperative day. One death has occurred due to a gunshot wound. Conclusions: Interim data in LAANTERN epilepsy patients indicate LITT to be a safe treatment consideration for drug resistant epilepsy with overall seizure freedom outcome for TLE comparable to previously reported outcomes. Funding: The LAANTERN registry is funded by Monteris Medical.