Laser interstitial thermotherapy (LiTT) in epilepsy surgery

Besides other innovative stereotactic procedures (radiofrequency thermocoagulation, focused ultrasound, gamma knife) laser interstitial thermotherapy (LiTT) provides minimally invasive destruction of pathological soft tissues which could be especially relevant for epilepsy surgeries involving adult and pediatric patients. Unlike standard resections, no craniotomy is required; just a tiny borehole trepanation is sufficient. Damage to cortical areas when accessing deep lesions can be minimized or completely avoided, and treating epileptogenic foci near eloquent or even vital brain areas becomes possible. Here, we briefly describe the history and rationale of laser neurosurgery as well as the technical key features of the two currently available systems for magnetic resonance-guided LiTT (Visualase^®, NeuroBlate^®; CE marks pending for both). We also discuss the published clinical experience with LiTT in the field of epilepsy surgery (approximately 200 cases) with regard to complications, LiTT-induced, long-term brain structural alterations, seizure outcome, preliminary neuropsychological findings and first estimates of treatment costs. Overall, the seizure outcome appears to be slightly worse than for resective surgery. Due to insufficient research methods (e.g. non-established measures, lack of a control condition), the expected neuropsychological superiority over resective surgery has not been unambiguously demonstrated thus far. Also, the cost-benefit ratio requires further critical evaluation. Clinical, multi-center and adequately controlled outcome studies of high quality should also accompany the imminent introduction of LiTT into the field of epilepsy surgery and therewith permit critical scientific evaluation and rational, individual, clinical decisions.