Clinical outcomes and learning curve of MRgLITT system for drug-resistant epilepsy in China: A single-center retrospective study.

Minimally invasive magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been proposed as an alternative to open epilepsy surgery, to address concerns regarding the risk of open surgery. Our primary hypothesis was that seizure freedom at 1 year after MRgLITT is noninferior to open surgery in children with drug-resistant epilepsy (DRE). The secondary hypothesis was that MRgLITT has fewer complications and shorter hospitalization than surgery. The primary objective was to compare seizure outcome of MRgLITT to open surgery in children with DRE. The secondary objective was to compare complications and length of hospitalization of the two treatments. This retrospective multicenter cohort study included children with DRE treated with MRgLITT or open surgery with 1-year follow-up. Exclusion criteria were corpus callosotomy, neurostimulation, multilobar or hemispheric surgery, and lesion with maximal dimension > 60 mm. MRgLITT patients were propensity matched to open surgery patients. The primary outcome was seizure freedom at 1 year posttreatment. The difference in seizure freedom was compared using noninferiority test, with noninferiority margin of -10%. The secondary outcomes were complications and length of hospitalization. One hundred eighty-five MRgLITT patients were matched to 185 open surgery patients. Seizure freedom at 1 year follow-up was observed in 89 of 185 (48.1%) MRgLITT and 114 of 185 (61.6%) open surgery patients (difference=-13.5%, one-sided 97.5% confidence interval = -23.8% to ∞, pNoninferiority = .79). The lower confidence interval boundary of -23.8% was below the prespecified noninferiority margin of -10%. Overall complications were lower in MRgLITT compared to open surgery (10.8% vs. 29.2%, respectively, p< .001). Hospitalization was shorter for MRgLITT than open surgery (3.1± 2.9 vs. 7.2± 6.1 days, p< .001). Seizure outcome of MRgLITT at 1 year posttreatment was inferior to open surgery. However, MRgLITT has the advantage of better safety profile and shorter hospitalization. The findings will help counsel children and parents on the benefits and risks of MRgLITT and contribute to informed decision-making on treatment options.

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) and traditional open surgery (OS) are effective and safe options for patients with drug-resistant mesial temporal lobe epilepsy (DR-mTLE). However, their superiority in seizure control and preservation of functional abilities remains unclear. This study aimed to compare the surgical outcomes of MRgLITT and OS. This multicenter retrospective cohort study included patients with DR-mTLE who underwent MRgLITT or OS at three centres between 2015 and 2023. The data on patient demographics, presurgical non-invasive evaluation, stereoelectroencephalography (SEEG) implantation, memory alteration, and seizure outcomes were collected. Propensity score matching (PSM) analysis was conducted for the comparison of seizure control and functional preservation between two surgical approaches. Of the 244 individuals who met the study criteria, 33 underwent MRgLITT and 211 OS. The median (interquartile range) age at seizure onset was 22.0 (13.0) and 12.3 (10.0) years in the MRgLITT and OS groups, respectively. The first PSM, based on demographic and non-invasive information, resulted in 26 matched pairs for the primary analysis. There were no significant differences in memory preservation ( P = 0.95) or surgical outcomes ( P = 0.96) between the groups. The second PSM, based on demographics and SEEG implantation, yielded 32 matched pairs for the sensitivity analysis, showing similar results. Subset analysis of early and late MRgLITT cases revealed no statistically significant differences in the proportion of patients with memory decline ( P = 0.42) or seizure control ( P = 1.00). Patients who underwent SEEG implantation were 96% less likely to achieve seizure freedom after MRgLITT ( P = 0.02). Minimally invasive MRgLITT is associated with memory preservation and seizure control, similar to traditional OS. MRgLITT is effective and safe for DR-mTLE and is relevant for future prospective randomized trials on dominant-side mTLE, providing practical implications for guiding neurosurgeons in the selection of surgical approaches.

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to open resection for pediatric drug-resistant epilepsy (DRE). This systematic review and individual participant data meta-analysis aimed to identify independent predictors of seizure outcomes and operative and neurological complications following MRgLITT. Uni- and multivariable mixed-effects Cox proportional-hazards regressions models were used to identify independent predictors of time to seizure recurrence following MRgLITT. Among patients with at least 12 months of follow-up, uni- and multivariable mixed-effects logistic regression analyses were conducted to ascertain the independent risk factors associated with seizure recurrence at last follow-up, operative complications, and postoperative neurological complications. A literature review identified 354 pediatric patients with a mean epilepsy duration of 7.5 (SD 5.3) years prior to MRgLITT. The mean age at seizure onset was 4.52 (SD 4.69) years, and focal seizures were more common (85.5%) than generalized seizures (14.5%). Lesions were detected on MRI in 82.1% of cases. The most common epilepsy etiologies were hypothalamic hamartoma (HH; 23.7%) and malformations of cortical development (23.7%). The mean follow-up duration after MRgLITT was 16.02 (SD 11.63) months. Engel class I outcomes were achieved in 57% of patients. In 205 cases where information was available regarding postoperative neurological complications, 35 patients (17.1%) experienced postoperative neurological complications, with hemiparesis as the most frequent complication (n = 16 patients). Of the 354 total patients who underwent MRgLITT, 8.2% underwent revision epilepsy surgery. No operative or clinical characteristics were associated with seizure recurrence. Seizure freedom probability was significantly higher among patients with HH compared to those with nonlesional MRI (p = 0.012). Patients with mesial temporal sclerosis experienced earlier seizure recurrence (p = 0.023), and an extratemporal surgical location was associated with longer seizure freedom probability (p = 0.034). Lesional MRI was associated with reduced odds of postoperative neurological complications (p = 0.031). MRgLITT may be a safe and effective alternative option for pediatric DRE. Further prospective studies are warranted to elucidate MRgLITT strategies in pediatric DRE.

INTRODUCTION: Epilepsy affects up to 0.5% of children, with one-third considered for surgery due to medical refractoriness. Studies show surgery offers better seizure freedom for drug-resistant epilepsy than medical therapy. However, it is underutilized due to potential complications and postoperative deficits, which have improved over time. This study evaluates the indications for MRgLITT compared to resective procedures and assesses perioperative variables, including seizure outcomes, in pediatric patients undergoing MRgLITT. We report the indications and outcomes, providing a statistical comparison to resective surgery. METHODS: All patients (n = 675) undergoing operative interventions for epilepsy from The Pediatric Epilepsy Research Consortium (PERC) were included. Using Chi-squared and Mann-Whitney-Wilcoxon tests, all available patient variables were compared between MRgLITT (n = 141) and open surgery (n = 534). All putative variables were included in multivariable logistic regression to identify independent predictors of seizure freedom. RESULTS: Patients undergoing MRgLITT were older at referral and surgery, had longer times to surgery, and more failed anti-seizure medications (ASMs), with no differences in race or insurance type compared to resective surgery patients. MRgLITT patients also had distinct etiologies, hemispheric involvement, operative locations, and higher use of invasive monitoring. Seizure freedom was achieved in 50% of MRgLITT patients versus 64% in resective surgery patients (p &lt; 0.001). Fewer failed ASMs was the only independent predictor of postoperative seizure freedom (OR = 1.16, p = 0.012). While MRgLITT showed worse odds of seizure freedom in univariable analysis, it had equivalent outcomes to resective surgery in multivariable analysis. CONCLUSIONS: Given differences in patient variables, indications, and outcomes, MRgLITT has a distinct role in pediatric epilepsy surgery for select patients. Identified factors should guide patient selection/counseling. Prognosticating outcomes for MRgLITT patients is limited by the heterogeneous population, warranting further investigation.

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a popular minimally invasive alternative to open resective surgery for drug-resistant epilepsy (DRE). We sought to perform a systematic review and individual participant data meta-analysis to identify independent predictors of seizure outcome and complications following MRgLITT for DRE. Eleven databases were searched from January 1, 2010 to February 6, 2021 using the terms "MR-guided ablation therapy" and "epilepsy". Multivariable mixed-effects Cox and logistic regression identified predictors of time to seizure recurrence, seizure freedom, operative complications, and postoperative neurological deficits. From 8705 citations, 46 studies reporting on 450 MRgLITT DRE patients (mean age=29.5± 18.1 years, 49.6% female) were included. Median postoperative seizure freedom and follow-up duration were 15.5 and 19.0months, respectively. Overall, 240 (57.8%) of 415 patients (excluding palliative corpus callosotomy) were seizure-free at last follow-up. Generalized seizure semiology (hazard ratio [HR]=1.78, p= .020) and nonlesional magnetic resonance imaging (MRI) findings (HR=1.50, p= .032) independently predicted shorter time to seizure recurrence. Cerebral cavernous malformation (CCM; odds ratio [OR]=7.97, p< .001) and mesial temporal sclerosis/atrophy (MTS/A; OR=2.21, p= .011) were independently associated with greater odds of seizure freedom at last follow-up. Operative complications occurred in 28 (8.5%) of 330 patients and were independently associated with extratemporal ablations (OR=5.40, p= .012) and nonlesional MRI studies (OR=3.25, p= .017). Postoperative neurological deficits were observed in 53 (15.1%) of 352 patients and were independently predicted by hypothalamic hamartoma etiology (OR=5.93, p= .006) and invasive electroencephalographic monitoring (OR=4.83, p= .003). Overall, MRgLITT is particularly effective in treating patients with well-circumscribed lesional DRE, such as CCM and MTS/A, but less effective in nonlesional cases or lesional cases with a more diffuse epileptogenic network associated with generalized seizures. This study identifies independent predictors of seizure freedom and complications following MRgLITT that may help further guide patient selection.

Laser Interstitial Thermal Therapy versus Open Surgery for Mesial Temporal Lobe Epilepsy: A Systematic Review and Meta-Analysis

BACKGROUND For patients with focal drug-resistant epilepsy (DRE), surgical resection of the epileptogenic zone (EZ) may offer seizure freedom and benefits for quality of life. Yet, concerns remain regarding invasiveness, morbidity, and neurocognitive side effects. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a less invasive option for stereotactic ablation rather than resection of the EZ. OBJECTIVE To provide an introduction to MRgLITT for epilepsy, including historical development, surgical technique, and role in therapy. METHODS The development of MRgLITT is briefly recounted. A systematic review identified reported techniques and indication-specific outcomes of MRgLITT for DRE in human studies regardless of sample size or follow-up duration. Potential advantages and disadvantages compared to available alternatives for each indication are assessed in an unstructured review. RESULTS Techniques and outcomes are reported for mesial temporal lobe epilepsy, hypothalamic hamartoma, focal cortical dysplasia, nonlesional epilepsy, tuberous sclerosis, periventricular nodular heterotopia, cerebral cavernous malformations, poststroke epilepsy, temporal encephalocele, and corpus callosotomy. CONCLUSION MRgLITT offers access to foci virtually anywhere in the brain with minimal disruption of the overlying cortex and white matter, promising fewer neurological side effects and less surgical morbidity and pain. Compared to other ablative techniques, MRgLITT offers immediate, discrete lesions with real-time monitoring of temperature beyond the fiber tip for damage estimates and off-target injury prevention. Applications of MRgLITT for epilepsy are growing rapidly and, although more evidence of safety and efficacy is needed, there are potential advantages for some patients.

This systematic review and meta-analysis aimed to compare neuropsychological outcomes following traditional surgical approaches and magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) in patients with drug-resistant mesial temporal lobe epilepsy. Thirty-four studies were included; 24 reported cognitive outcomes following open resection, seven following MRgLITT, and three reported on both procedures. Meta-analyses of proportions, subgroup comparisons, and meta-regressions were conducted across three cognitive domains: verbal memory, visual memory, and naming, stratified by surgical laterality and procedure type. In left-sided surgery, verbal memory decline occurred in 36% (95% confidence interval [CI] = 28%-45%) after open resection and 29% (95% CI = 9%-62%) after MRgLITT, with no significant difference (p = .5967). For right-sided procedures, visual memory decline was similar between open resection (16%, 95% CI = 8%-29%) and MRgLITT (19%, 95% CI = 3%-61%; p = .8027). Left-sided naming decline was higher after open resection (43%, 95% CI = 27%-61%) than MRgLITT (9%, 95% CI = 3%-22%; p < .0001), a difference supported in subgroup and meta-regression analyses. Exploratory meta-regression suggested a borderline association between higher seizure freedom and greater naming decline (p = .0508), but MRgLITT retained a protective effect after adjusting for seizure outcomes (β = -1.36, 95% CI = -2.20 to -.51; p = .0016). Regardless of the approach, naming improvement occurred in 27% of patients in each group after right-sided surgery, indicating substantial recovery when the left hemisphere is preserved. Verbal memory showed a nonsignificant trend toward better preservation with MRgLITT, whereas visual memory was comparable across approaches. MRgLITT significantly preserved naming after left-sided surgery, offering a clear cognitive benefit over traditional open resection.

A comparison between magnetic resonance-guided laser interstitial thermal therapy and resective surgery for drug-resistant epilepsy in patients with MRI-positive focal cortical dysplasia: A systematic review and meta-analysis.

Radiation necrosis is becoming an increasingly prevalent complication in patients with brain tumors given the growing utility of stereotactic radiosurgery in modern treatment paradigms. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a new minimally invasive modality that has exhibited an efficacy comparable to craniotomy in treating radiation necrosis. No studies to date have compared their cost-effectiveness despite the significant additional expenses associated with MRgLITT use. This study aimed to evaluate the cost-effectiveness of MRgLITT versus craniotomy in patients with comparable presentations of radiation necrosis. The National Inpatient Sample (NIS) was queried from 2011 to 2020 for patients with radiation necrosis and treated using craniotomy or MRgLITT. Admission charges and costs were inflation adjusted to 2020 $US. Surgical cohorts were propensity score-matched according to demographic, clinical, and admission characteristics. Multivariable linear and logistic regression analyses identified associations between type of intervention and outcomes. A semi-Markov model was created to simulate treatment with craniotomy versus MRgLITT. Cost, transition probabilities, and health state utilities were derived from the NIS, individual patient outcomes from multiple institutions, and prospectively collected quality-of-life data from a single institution and verified against other studies. Monte Carlo simulation and probabilistic sensitivity analysis were used to evaluate the cost-effectiveness between the two modalities. In the designated study period, 2869 patients had been admitted with brain tumor radiation necrosis and were managed with neurosurgical intervention. After propensity score matching, MRgLITT, relative to craniotomy, was independently associated with a shorter length of stay (LOS; β = -1.81, p = 0.002), lower odds of complications (OR 0.18, p = 0.033), and higher odds of home discharge (OR 3.05, p = 0.041), but there was no difference in total admission costs between the two modalities (β = $6229, p = 0.081). On Monte Carlo simulation, patients treated with MRgLITT had a lower probability of disease (radiation necrosis or tumor) recurrence (13.5% vs 22.0%, p < 0.001) but an equivalent mortality risk (22.8% vs 22.3%, p = 0.429) compared to the patients treated with craniotomy at the 1-year follow-up. Over a 4-year time horizon, MRgLITT had an incremental cost of -$25,685 and incremental effectiveness of 0.14 quality-adjusted life-year (QALY), resulting in an incremental cost-effectiveness ratio of -$183,464 per QALY relative to craniotomy. MRgLITT was a more cost-effective treatment strategy than craniotomy in the management of patients with brain tumor radiation necrosis. The cost-effectiveness of MRgLITT may be attributed to a shorter LOS, lower complication odds, and higher home discharge odds in the immediate postoperative period and a lower risk of disease recurrence over the long-term follow-up.

Magnetic resonance-guided laser interstitial thermal therapy (MR-gLiTT) is a novel minimally invasive treatment approach for drug-resistant focal epilepsy and brain tumors. Using thermal ablation induced by a laser diode implanted intracranially in a stereotactic manner, the technique is highly effective and safe, reducing the risk associated with more traditional open surgical approaches that could lead to increased neurological morbidity. Indications for MR-gLiTT in pediatric epilepsy surgery include hypothalamic hamartoma, tuberous sclerosis complex, cavernoma-related epilepsy, SEEG-guided seizure onset zone ablation, corpus callosotomy, periventricular nodular heterotopia, mesial temporal lobe epilepsy, and insular epilepsy. We review the available literature on the topic and present our series of patients with drug-resistant epilepsy treated by MR-gLiTT. Our experience, represented by six cases of hypothalamic hamartomas, one case of tuberous sclerosis, and one case of dysembryoplastic neuroepithelial tumor, helps to confirm that MR-gLiTT is a highly safe and effective procedure for several epilepsy conditions in children.

For patients with focal drug-resistant epilepsy (DRE), surgical resection of the epileptogenic zone (EZ) may offer seizure freedom and benefits for quality of life. Yet, concerns remain regarding invasiveness, morbidity, and neurocognitive side effects. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a less invasive option for stereotactic ablation rather than resection of the EZ. To provide an introduction to MRgLITT for epilepsy, including historical development, surgical technique, and role in therapy. The development of MRgLITT is briefly recounted. A systematic review identified reported techniques and indication-specific outcomes of MRgLITT for DRE in human studies regardless of sample size or follow-up duration. Potential advantages and disadvantages compared to available alternatives for each indication are assessed in an unstructured review. Techniques and outcomes are reported for mesial temporal lobe epilepsy, hypothalamic hamartoma, focal cortical dysplasia, nonlesional epilepsy, tuberous sclerosis, periventricular nodular heterotopia, cerebral cavernous malformations, poststroke epilepsy, temporal encephalocele, and corpus callosotomy. MRgLITT offers access to foci virtually anywhere in the brain with minimal disruption of the overlying cortex and white matter, promising fewer neurological side effects and less surgical morbidity and pain. Compared to other ablative techniques, MRgLITT offers immediate, discrete lesions with real-time monitoring of temperature beyond the fiber tip for damage estimates and off-target injury prevention. Applications of MRgLITT for epilepsy are growing rapidly and, although more evidence of safety and efficacy is needed, there are potential advantages for some patients.

Impact of Previous Surgery on Success of Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) to Treat Pediatric Epilepsy: An Institutional Experience

Temporal encephalocele (TE) is a rare but surgically treatable/curable cause of temporal lobe epilepsy (TLE). The surgical intervention varies from local disconnection to extensive anterior temporal lobectomy and amygdalohippocampectomy (ATL/AH). Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has evolved as a minimally invasive alternative for intractable epilepsy with good results, however, application of MRgLITT for intractable pediatric epilepsy secondary to TE has not been reported. We present a detailed technical report and clinical experience of MRgLITT in two adolescent children with medically intractable TLE secondary to TE. Pre-surgical evaluation revealed anterior inferior TE with concordant clinico-electrophysiological data. Both the patients underwent MRgLITT after review with the institutional multidisciplinary epilepsy team and discussion with the patient and the family. Both the patients were discharged on post-operative day one and have been seizure-free since the procedure at the last follow-up visit at 18 months and 6 months, respectively. The present series demonstrates first-ever clinical and technical experience of MRgLITT for TE with intractable pediatric epilepsy. The excellent post-operative seizure outcome and favorable postoperative course support MRgLITT as the first line of surgical intervention for TE with intractable TLE and broadens the application of MRgLITT.

Laser ablation therapy: An alternative treatment for medically resistant mesial temporal lobe epilepsy after age 50.