Automated trajectory planning for laser interstitial thermal therapy in mesial temporal lobe epilepsy

Abstract

SummaryObjectiveSurgical resection of the mesial temporal structures brings seizure remission in 65% of individuals with drug‐resistant mesial temporal lobe epilepsy (MTLE). Laser interstitial thermal therapy (LiTT) is a novel therapy that may provide a minimally invasive means of ablating the mesial temporal structures with similar outcomes, while minimizing damage to the neocortex. Systematic trajectory planning helps ensure safety and optimal seizure freedom through adequate ablation of the amygdalohippocampal complex (AHC). Previous studies have highlighted the relationship between the residual unablated mesial hippocampal head and failure to achieve seizure freedom. We aim to implement computer‐assisted planning (CAP) to improve the ablation volume and safety of LiTT trajectories.MethodsTwenty‐five patients who had previously undergone LiTT for MTLE were studied retrospectively. The EpiNav platform was used to automatically generate an optimal ablation trajectory, which was compared with the previous manually planned and implemented trajectory. Expected ablation volumes and safety profiles of each trajectory were modeled. The implemented laser trajectory and achieved ablation of mesial temporal lobe structures were quantified and correlated with seizure outcome.Results CAP automatically generated feasible trajectories with reduced overall risk metrics (P < .001) and intracerebral length (P = .007). There was a significant correlation between the actual and retrospective CAP‐anticipated ablation volumes, supporting a 15 mm diameter ablation zone model (P < .001). CAP trajectories would have provided significantly greater ablation of the amygdala (P = .0004) and AHC (P = .008), resulting in less residual unablated mesial hippocampal head (P = .001), and reduced ablation of the parahippocampal gyrus (P = .02).SignificanceCompared to manually planned trajectories CAP provides a better safety profile, with potentially improved seizure‐free outcome and reduced neuropsychological deficits, following LiTT for MTLE.

Effects of surgical targeting in laser interstitial thermal therapy for mesial temporal lobe epilepsy: A multicenter study of 234 patients

“…[3][4][5][6][8][9][10][11][12] Unfortunately, without consideration of specific therapy location, which is subject to variability in patient anatomy and the surgery itself, these studies are limited in their ability to reliably report clinical outcomes. [3][4][5][6][8][9][10][11][12] Unfortunately, without consideration of specific therapy location, which is subject to variability in patient anatomy and the surgery itself, these studies are limited in their ability to reliably report clinical outcomes.…”

Multicenter validation of automated trajectories for selective laser amygdalohippocampectomy

“…Computer‐assisted planning (CAP) for automated generation of LITT trajectories using EpiNav was performed prior to assessment of the manually implemented trajectory and has been described previously. We refer readers to our previous work for a more in‐depth description of the CAP algorithm . In brief, a preoperative T1 image is used to generate a patient‐specific whole‐brain parcellation and pseudoCT using geodesic information flows (GIFs).…”

“…Given the lack of evidence defining optimal ablation parameters for a seizure‐free outcome, neurosurgeons apply a number of heuristics when planning LITT trajectories . These include identifying an avascular corridor for the laser catheter, avoidance of ventricles and sulci where possible, ablation of the hippocampus back to the level of the tectum, and maximizing distance from critical structures such as the brainstem and lateral geniculate nucleus . In addition, minimizing the intracerebral length of the trajectory and drilling angle to the skull may reduce parenchymal transgression and implantation inaccuracy, respectively.…”

“…We have previously derived LITT trajectory parameters from expert opinion and incorporated this into the EpiNav (King's College London) software platform to automate LITT trajectory parameters . We demonstrated improved trajectory metrics including estimated ablation volumes of the amygdalohippocampal complex (AHC) over manually planned trajectories.…”

Anterior Corpus Callosotomy Using Laser Interstitial Thermal Therapy for Refractory Epilepsy

“…Laser interstitial thermal therapy (LITT) is a minimally invasive, stereotactic-guided surgical technique, which has shown favorable outcomes in patients with a variety of brain lesions including those with brain tumors [7-9] and epilepsy [10, 11]. The minimally invasive nature of LITT offers significant advantages over open surgical procedures in terms of length of hospital stay, blood loss, and size of surgical incision.…”