Effects of surgical targeting in laser interstitial thermal therapy for mesial temporal lobe epilepsy: A multicenter study of 234 patients.
OBJECTIVE
Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE.


METHODS
This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively.


RESULTS
Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome.


SIGNIFICANCE
LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.
['Wu|Chengyuan|C|0000-0002-3954-2929', 'Jermakowicz|Walter J|WJ|', 'Chakravorti|Srijata|S|', 'Cajigas|Iahn|I|0000-0002-5808-453X', 'Sharan|Ashwini D|AD|', 'Jagid|Jonathan R|JR|', 'Matias|Caio M|CM|', 'Sperling|Michael R|MR|', 'Buckley|Robert|R|', 'Ko|Andrew|A|', 'Ojemann|Jeffrey G|JG|', 'Miller|John W|JW|', 'Youngerman|Brett|B|0000-0002-4792-3190', 'Sheth|Sameer A|SA|', 'McKhann|Guy M|GM|', 'Laxton|Adrian W|AW|', 'Couture|Daniel E|DE|', 'Popli|Gautam S|GS|', 'Smith|Alexander|A|', 'Mehta|Ashesh D|AD|', 'Ho|Allen L|AL|', 'Halpern|Casey H|CH|', 'Englot|Dario J|DJ|', 'Neimat|Joseph S|JS|', 'Konrad|Peter E|PE|', 'Neal|Elliot|E|0000-0002-5012-5704', 'Vale|Fernando L|FL|', 'Holloway|Kathryn L|KL|', 'Air|Ellen L|EL|', 'Schwalb|Jason|J|', 'Dawant|Benoit M|BM|', "D'Haese|Pierre-Francois|PF|"]
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D000679:Amygdala D002648:Child D015331:Cohort Studies D004833:Epilepsy, Temporal Lobe D004830:Epilepsy, Tonic-Clonic D005260:Female D006801:Humans D053685:Laser Therapy D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D012189:Retrospective Studies D012640:Seizures D016896:Treatment Outcome D055815:Young Adult
ablation MRI amygdalohippocampectomy stereotactic surgery