036. Stereoelectroencephalography Followed by MR-guided Laser Interstitial Thermal Therapy or Open Resection: A Single-Center Surgical Series in Pediatric Patients with Medically Refractory Epilepsy

Authors: Anna Leigh Slingerland

Stereoelectroencephalography (sEEG) and Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) have emerged as safe, effective, and less invasive alternatives to subdural grid placement and open resection respectively for localization and treatment of medically refractory epilepsy (MRE) in children. Reported pediatric experience combining these complementary techniques is limited. We describe the largest series of pediatric epilepsy patients undergoing MRgLITT following sEEG, contrasted with a cohort undergoing craniotomy following sEEG.Methods: All patients with MRE who underwent sEEG followed by MRgLITT or open resection/disconnection at Boston Children’s Hospital between November 2015 and December 2020 were retrospectively reviewed. Primary outcome variables included surgical complication rates, length of hospital stay following treatment, and Engel classification at last follow-up.
Out of 60 sEEG patients, 21 (median age 12.1 years, 66.7% female) underwent MRgLITT, and 39 (median age 11.5 years, 43.6% female) underwent craniotomy. Fifty-seven patients (95%) underwent sEEG followed by combined electrode removal and treatment. Eight MRgLITT cases (33.3%), and no open cases, targeted the insula (p < 0.001). Complications rates did not differ, though trends to more subdural/epidural hematomas, infarcts, and permanent unanticipated neurological deficits were evident following craniotomy, while a trend to more temporary unanticipated neurologic deficits was seen following MRgLITT. The median duration of hospitalization after treatment was 3 and 5 days for MRgLITT and open cases respectively (p < 0.001). Seizure outcomes were similar, with 57% of MRgLITT and 59% of craniotomy patients achieving seizure freedom at last follow-up (p=0.878, median 14.8 and 18.2 months respectively).
MRgLITT and open resection following sEEG can both effectively treat localized epileptogenic foci in pediatric patients, and generally be performed in a two-surgery workflow. In appropriately selected patients, MRgLITT is associated with a shorter hospitalization following treatment and potentially fewer complications, and may be best-suited for focal deep-seated targets associated with relatively challenging open surgical approaches.