MRI-guided Laser Interstitial Thermal Therapy Research Articles

Open surgery or laser interstitial thermal therapy for low-grade epilepsy-associated tumors of the temporal lobe: A single-institution consecutive series

Outcomes of treating low-grade epilepsy-associated tumors (LEATs) in the temporal lobe with MRI-guided laser interstitial thermal therapy (MRgLITT) remain poorly characterized. This study aimed to compare the safety and effectiveness of treating temporal lobe LEATs with MRgLITT versus open resection in a consecutive single-institution series. We reviewed all adult patients with epilepsy that underwent surgery for temporal lobe LEATs at our institution between 2002 and 2019, during which time we switched from open surgery to MRgLITT. Surgical outcome was categorized by Engel classification at >12mo follow-up and Kaplan–Meir analysis of seizure freedom. We recorded hospital length of stay, adverse events, and available neuropsychological results. Of 14 total patients, 7 underwent 9 open resections, 6 patients underwent MRgLITT alone, and 1 patient underwent an open resection followed by MRgLITT. Baseline group demographics differed and were notable for preoperative duration of epilepsy of 9.0 years (range 1–36) for open resection versus 14.0 years (range 2–34) for MRgLITT. Median length of stay was one day shorter for MRgLITT compared to open resection (p=<.0001). There were no major adverse events in the series, but there were fewer minor adverse events following MRgLITT. At 12mo follow-up, 50% (5/10) of patients undergoing open resection and 57% (4/7) of patients undergoing MRgLITT were free of disabling seizures (Engel I). When comparing patients who underwent similar procedures in the dominant temporal lobe, patients undergoing MRgLITT had fewer and milder material-specific neuropsychological declines than patients undergoing open resections. In this small series, MRgLITT was comparably safe and effective relative to open resection of temporal lobe LEATs.

131 Multi-Institutional Study on MRI-guided Laser Interstitial Thermal Therapy for Corpus Callosotomy (MRIgLITT-CC): Technique Variation, Ablation Coverage, and Need for Additional Surgery

INTRODUCTION: MRI-guided laser interstitial thermal therapy for corpus callosotomy (MRIgLITT-CC) offers palliation of intractable drop events and atonic, tonic, and generalized tonic-clonic seizures. METHODS: This multi-institutional retrospective study included pediatric patients with medically intractable epilepsy undergoing MRIgLITT-CC. Surgical details, post-operative radiographic results, and need for additional epilepsy surgery were recorded. Percent coverages of the intended ablation zones (anterior, complete, or posterior corpus callosotomy) were estimated from MRI. Data were summarized using descriptive statistics and compared using Chi-square tests. RESULTS: A total of 27 subjects (18 male, 9 female) with mean age 13 years +/- 5 years (4 years, 21 years) underwent planned complete (13, 48%), anterior (11, 41%), or posterior (3, 11%) MRIgLITT-CC. Planned complete MRIgLITT-CC entailed 2 (1/13, 8%), 3 (6/13, 46%), or 4 (6/13, 46%) trajectories with 100% (8/13, 62%) or 95-99% (5/13, 38%) coverage of the planned callosal ablation zone. Anterior MRIgLITT-CC cases included 1 (1/11, 9%), 2 (8/11, 73%), or 3 (1/11, 9%) trajectories to achieve 100% (7/11, 64%), 95-99% (2/11, 18%), 90-94% (1/11, 9%), or &lt;90% (1/11, 9%) coverage of the planned callosal ablation zone. There were no significant differences in percent coverage of intended ablation zone as a function of trajectory number (p = 0.6). Three subjects (11%) required repeat callosal surgery while four subjects (15%) underwent additional vagus nerve stimulator (VNS) insertion during clinic follow-up (mean 11.7 months +/-10.6 months; [0.4 months, 37.1 months]). The need for repeat callosal surgery differed significantly between subjects with 100% and less than 100% ablation coverage (0/16 vs. 3/11, p = 0.03). CONCLUSION: In this multi-institutional study, MRIgLITT-CC yielded 100% or 95-99% coverage of the intended callosal ablation zone in most subjects. Trajectory variation between centers did not impact percent coverage of the intended ablation zone. Few subjects required repeat callosal surgery, particularly those with less than 100% ablation zone coverage, or additional VNS insertion.

144 Interstitial Laser Anterior Capsulotomy for Obsessive-compulsive Disorder: Lesion Size and Tractography Correlate with Outcome

INTRODUCTION: Anterior capsulotomy is a well-established treatment for refractory obsessive-compulsive disorder (OCD) and has been performed with radiofrequency ablation, stereotactic radiosurgery, and focused ultrasound. MRI-guided laser interstitial thermal therapy (LITT) allows creation of larger, more demarcated lesions with the safety conferred by real-time imaging of the ablation volume. METHODS: Patients with severe OCD refractory to pharmacotherapy and cognitive-behavioral therapy underwent bilateral anterior capsulotomy via LITT. The primary outcome was percent reduction in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score over time. Lesion size was measured on post-ablation MRI. Disconnection of the anterior limb of the internal capsule (ALIC) was assessed via individual and normative tractography. RESULTS: Eighteen patients underwent laser anterior capsulotomy. Median follow-up was 6 months (range 3-51 months). Time occupied by obsessions improved immediately (median Y-BOCS item 1 score 4 to 1, P = 0.0002). Mean (± standard deviation) decrease in Y-BOCS score at last follow-up was 46 ± 32% (16 ± 11 points; P = 0.0002). Sixty-one percent of patients were responders. One patient had an asymptomatic intracerebral hemorrhage. Reduction in Y-BOCS score was positively associated with ablation volume (P = 0.006). Individual tractography demonstrated durable ALIC disconnection. Normative tractography revealed a dorsal-ventral gradient, with disconnection of orbitofrontal streamlines most strongly associated with a positive response to surgery (P &lt; 0.0001). CONCLUSION: Laser anterior capsulotomy resulted in immediate, marked improvement in OCD symptom severity. Larger lesions can be created safely and permit greater disconnection of the prefrontal-subcortical pathways involved in OCD. The importance of greater disconnection is presumably related to variation in ALIC structure and the complex role of the PFC in OCD.

Laser ablation for corpus callosotomy: Systematic review and pooled analysis

PurposeThe Laser interstitial thermal therapy (LITT) technique has been used recently for corpus callosotomy in patients with epilepsy, especially atonic seizures (drop attacks) and Lennox-Gastaut Syndrome (LGS). However, there is little data on safety and outcomes. Therefore, the authors systematically studied and conducted a pooled analysis with special focus on feasibility, outcomes and complications. MethodsA systematic review was performed in accordance with the PRISMA guidelines. A total of 10 retrospective studies were identified, comprising 58 cases of MRI-guided LITT treatment. ResultsMRI-guided LITT was successfully performed in 57 cases while one case was aborted due to hemorrhage. The average duration of clinical follow-up following LITT callosotomy was 20 months. In the 57 LITT callosotomies, complete seizure freedom and excellent seizure control (Engel I and II) were achieved in 21.1% and 49.1% of patients, respectively. For atonic seizures, the rate of complete freedom and excellent control was 52.5% and 72.5%, respectively. The median length of stay at hospital was 2 days. No death was encountered. Common complications included: fiber-related hemorrhage (8.6%), inaccurate placement (6.9%) followed with transient hemiparesis/hemineglect and supplementary motor area (SMA) syndrome 5.2% each. The rate of disconnection syndrome was 3.4%. ConclusionMRI-guided LITT for corpus callosotomy is feasible and safe, with low complication rates, short hospitalization and has comparable rates of seizure control to that of classic surgical callosotomy. The majority of patients with atonic seizures achieve complete seizure freedom and excellent control (Engel I and II). The risk for developing disconnection syndrome is low.

CTIM-09. PHASE I STUDY OF PD-L1 INHIBITION WITH AVELUMAB AND LASER INTERSTITIAL THERMAL THERAPY IN PATIENTS WITH RECURRENT GLIOBLASTOMA

Abstract BACKGROUND The treatment of glioblastoma (GBM) poses many challenges. The use of immune checkpoint inhibition (ICI) has been disappointing as GBM is characterized by a low mutational burden and low infiltration by T cells. The combination of ICI with other treatment modalities may improve efficacy. METHODS Patients with recurrent GBM were treated with 800 mg avelumab, a human IgG1 antibody directed against PD-L1, either alone (in part A) or within a week after MRI-guided laser interstitial thermal therapy (LITT, in part B) and by-weekly thereafter (NCT03341806). To spare steroid use, bevacizumab was allowed to be combined with avelumab. The primary objective was to characterize the tolerability and safety of the regimen. The secondary objectives included overall survival, progression-free survival, and signature of plasma analytes. RESULTS A total of 12 patients (median age 64, range 37 - 73) enrolled from June 2018 to November 2019, 5 in part A and 7 in part B. Three serious adverse events (SAE) occurred in the same patient, not leading to death. There were 94 AEs reported, 5 grade 3, 28 grade 2, and 61 grade 1. The median PFS was 16.7 weeks (range 7.4-56.7) for patients in Part A and 30.9 weeks (range 8.5-77.7) for patients in Part B. The median survival for patients in part A was 11 months and 13.5 months for part B. The risk ratio of death by combining bevacizumab was 0.573 (p=0.258) with significantly decreased levels of peripheral blood plasma inflammatory markers such as EGF, CXCL5, VEGFA, LAP.TGβ1, ANGPT2 in women. CONCLUSIONS Avelumab was generally well-tolerated, and the combination with LITT had a manageable safety profile and increased survival in a subset of patients. The addition of bevacizumab may increase survival by lowering cytokine expression in a gender-dependent manner. These results warrant further investigation in the next phase study.

Interstitial laser anterior capsulotomy for obsessive–compulsive disorder: lesion size and tractography correlate with outcome

BackgroundAnterior capsulotomy is a well-established treatment for refractory obsessive–compulsive disorder (OCD). MRI-guided laser interstitial thermal therapy (LITT) allows creation of large, sharply demarcated lesions with the safeguard of real-time imaging.ObjectiveTo...

MRI-guided stereotactic laser corpus callosotomy for epilepsy: distinct methods and outcomes.

Several small series have described stereotactic MRI-guided laser interstitial thermal therapy for partial callosotomy of astatic and generalized tonic-clonic (GTC) seizures, especially in association with Lennox-Gastaut syndrome. Larger case series and comparison of distinct stereotactic methods for stereotactic laser corpus callosotomy (SLCC), however, are currently lacking. The objective of this study was to report seizure outcomes in a series of adult patients with epilepsy following anterior, posterior, and complete SLCC procedures and to compare the results achieved with a frameless stereotactic surgical robot versus direct MRI guidance frames. The authors retrospectively reviewed sequential adult epilepsy surgery patients who underwent SLCC procedures at a single institution. They describe workflows, stereotactic errors, percentage disconnection, hospitalization durations, adverse events, and seizure outcomes after performing anterior, posterior, and complete SLCC procedures using a frameless stereotactic surgical robot versus direct MRI guidance platforms. Thirteen patients underwent 15 SLCC procedures. The median age at surgery was 29 years (range 20-49 years), the median duration of epilepsy was 21 years (range 9-48 years), and median postablation follow-up was 20 months (range 4-44 months). Ten patients underwent anterior SLCC with a median 73% (range 33%-80%) midsagittal length of callosum acutely ablated. Following anterior SLCC, 6 of 10 patients achieved meaningful (> 50%) reduction of target seizures. Four patients underwent posterior (completion) SLCC following prior anterior callosotomy, and 1 patient underwent complete SLCC as a single procedure; 3 of these 5 patients experienced meaningful reduction of target seizures. Overall, 8 of 10 patients in whom astatic seizures were targeted and treated by anterior and/or posterior SLCC experienced meaningful improvement. SLCC procedures with direct MRI guidance (n = 7) versus a frameless surgical robot (n = 8) yielded median radial accuracies of 1.1 mm (range 0.2-2.0 mm) versus 2.4 mm (range 0.6-6.1 mm; p = 0.0011). The most serious adverse event was a clinically significant intraparenchymal hemorrhage in a patient who underwent the robotic technique. This is the largest reported series of SLCC for epilepsy to date. SLCC provides seizure outcomes comparable to open surgery outcomes reported in the literature. Direct MRI guidance is more accurate, which has the potential to reduce the risks of SLCC. Methodological advancements and larger studies are needed.

Surgical outcomes between temporal, extratemporal epilepsies and hypothalamic hamartoma: systematic review and meta-analysis of MRI-guided laser interstitial thermal therapy for drug-resistant epilepsy

BackgroundApproximately 1/3 of patients with epilepsy have drug-resistant epilepsy (DRE) and require surgical interventions. This meta-analysis aimed to review the effectiveness of MRI-guided laser interstitial thermal therapy (MRgLITT) in DRE.MethodsThe...

Anesthetic management and outcomes for MRI-guided laser interstitial thermal therapy (LITT) for seizure focus in pediatrics: A single-centre experience with 10 consecutive patients.

MRI-guided laser interstitial thermal therapy (LITT) is a stereotactically guided percutaneous minimally invasive procedure, which delivers light energy to tissue via a fiberoptic catheter, resulting in selective thermal ablation. Its use in drug-resistant epilepsy has increased because safety and efficacy have been well-established in adult and pediatric populations 1-4 . The anesthetic management of this procedure in children has not been previously reported. In our pediatric institution, MRI guided LITT is performed using the Visualase™ system (Medtronic, Minneapolis, MN). The typical procedural flow is described in Figure 1.

Stereotactic MRI-guided laser interstitial thermal therapy for extratemporal lobe epilepsy.

Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data±stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. Thirty-five patients with mean epilepsy duration of 21.3±12.2years underwent MRg-LITT for focal ETLE at a mean age 36.4±12.7years. A mean 2.59±1.45 trajectories per patient were used to obtain ablation volumes of 8.8±7.5cm3 . Mean follow-up was 27.3±19.5months. Of 32 patients with >12months of follow-up, 17 (53%) achieved good outcomes (Engel class I+II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P=.02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths-two seizure-associated and one suicide-were unrelated to surgical procedures. MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.

Systematic review of corpus callosotomy utilizing MRI guided laser interstitial thermal therapy

Corpus callosotomy is a palliative surgical option for patients with refractory epilepsy and frequent drop attacks, decreasing seizure frequency and severity by disconnecting the cerebral hemispheres. Though often successful, open surgery is not without risk. Corpus callosotomy by MRI-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to the standard open procedure. This report aims to present an illustrative case and systematically review the current literature on the surgical technique. A systematic review of the English literature through January 2019 was performed. Articles were searched by title utilizing the following key word combinations: “laser” and “callosotomy”, “callosotomy” and “ablation”, “laser” and “corpus”, “callosotomy” and “thermal”, and “stereotactic” and callosotomy”. The articles recovered were then classified by level of evidence and summarized. Fifteen papers were reviewed, of which 6 met inclusion and exclusion criteria. All included studies were classified as level IV evidence. There was a total of 13 patients ranging from 13 months to 44 years old (mean 23.5 years old). The number of laser fibers utilized ranged from 1 to 3. Engel class I was achieved in 5 patients, II in 4, III in 2, IV in 1. Reported patient follow up was 4–39.7 months (mean 15.43). Corpus callosotomy utilizing MRI-guided laser interstitial thermal therapy results in improvement in seizure frequency and severity with minimal complications. Prospective trials are needed to compare its seizure control and long-term outcomes to that of standard open callosotomy.

Highly realistic simulation for robot-assisted hypothalamic hamartoma real-time MRI-guided laser interstitial thermal therapy (LITT).

Real-time MRI-guided laser interstitial thermal therapy (LITT) is a challenging procedure due to its technical complexity, as well as the need for efficient multidisciplinary teamwork and transfer of an anesthetized patient between operating room (OR) and magnetic resonance (MR). A highly realistic simulation was developed to design the safest process before being applied to real patients. In this report, authors address the description of the methodology used for this simulation and its purposefulness. The entire image planning, anesthetic, and surgical process were performed on a modified pediatric simulation mannequin with a brain made of medical grade silicone including a hypothalamic hamartoma. Preoperative CT and MR were acquired. Stereotactic insertion of the optical fiber was assisted by the Neuromate® stereotactic robot. Laser ablation was performed with the Medtronic Visualase® MRI-guided system in a 3T Phillips Ingenia® MR scanner. All the stages of the process, participants, and equipment were the same as planned for a real surgery. No critical errors were found in the process design that prevented the procedure from being performed with adequate safety. Specific proposals for team positioning and interaction in patient transfers and in MR room were validated. Some specific elements that could improve safety were identified. Highly realistic simulation has been an extremely useful tool for safely planning LITT, because professionals were able to take actions in the workflow based not on ideas but on lived experiences. It contributed definitively to build a well-coordinated surgical team that worked safely and more efficiently.

MRI-Guided Laser Interstitial Thermal Therapy for Radiation Necrosis in Previously Irradiated Brain Arteriovenous Malformations

Radiation necrosis (RN) is a well-described complication after radiosurgery (SRS) for intracranial pathologies. It has been reported most frequently after SRS for brain metastases but has also been reported in up to 33% of patients with SRS-treated brain arteriovenous malformations (AVM).1 Treatment with chronic steroids has remained first-line therapy for several reasons: (1) many cases of RN can resolve spontaneously over time; and (2) most cases were treated initially with SRS owing to concerns for surgical morbidity of AVM resection, and in some cases, residual live AVM may coexist with RN.

Early economic evaluation of MRI-guided laser interstitial thermal therapy (MRgLITT) and epilepsy surgery for mesial temporal lobe epilepsy.

BackgroundMRI-guided laser interstitial thermal therapy (MRgLITT) is a new minimally invasive treatment for temporal lobe epilepsy (TLE), with limited effectiveness data. It is unknown if the cost savings associated with shorter hospitalization could offset the high equipment cost of MRgLITT. We examined the cost-utility of MRgLITT versus surgery for TLE from healthcare payer perspective, and the value of additional research to inform policy decision on MRgLITT.MethodsWe developed a microsimulation model to evaluate quality adjusted life years (QALYs), costs, and incremental cost-effectiveness ratio (ICER) of MRgLITT versus surgery in TLE, assuming life-time horizon and 1.5% discount rate. Model inputs were derived from the literature. We conducted threshold and sensitivity analyses to examine parameter uncertainties, and expected value of partial perfect information analyses to evaluate the expected monetary benefit of eliminating uncertainty on probabilities associated with MRgLITT.ResultsMRgLITT yielded 0.08 more QALYs and cost $7,821 higher than surgery, with ICER of $94,350/QALY. Influential parameters that could change model outcomes include probabilities of becoming seizure-free from disabling seizures state and returning to disabling seizures from seizure-free state 5 years after surgery and MRgLITT, cost of MRgLITT disposable equipment, and utilities of disabling seizures and seizure-free states of surgery and MRgLITT. The cost-effectiveness acceptability curve showed surgery was preferred in more than 50% of iterations. The expected monetary benefit of eliminating uncertainty for probabilities associated with MRgLITT was higher than for utilities associated with MRgLITT.ConclusionsMRgLITT resulted in more QALYs gained and higher costs compared to surgery in the base-case. The model was sensitive to variations in the cost of MRgLITT disposable equipment. There is value in conducting more research to reduce uncertainty on the probabilities and utilities of MRgLITT, but priority should be given to research focusing on improving the precision of estimates on effectiveness of MRgLITT.

Phase I study of PD-L1 inhibition with avelumab and laser interstitial thermal therapy in patients with recurrent glioblastoma.

TPS2074 Background: Glioblastoma (GBM) the most frequent malignant brain tumor in the adult has a dismal prognosis and limited treatment options. Current advances have highlighted how tumors and specifically GBM evade the immune system by exploiting the mechanisms of tolerance and inducing local and systemic immunosuppression. Another hurdle in the treatment of GBM is the blood-brain barrier (BBB). Recent work suggests that MRI-guided laser interstitial thermal therapy (LITT) can increase the permeability of the BBB and may have an abscopal effect. Therefore, utilizing MRI-guided LITT, a potential immunogenic cell death-inducing procedure that disrupts the BBB and makes Avelumab a PD-L1 monoclonal antibody being more accessible to GBM tumors, seem a valid approach for immunomodulation and successful implementation of a combined regimen to treat brain cancer. Methods: This is a prospective non-randomized open label to characterize the tolerability and safety profile of Avelumab in combination with LITT in patients with recurrent glioblastoma who were treated with radiation therapy with concurrent Temozolomide chemotherapy at diagnosis, and whose tumor at recurrence measures less then 3 cm3. Avelumab is administered within a week after real-time MRI-guided LITT therapy and every 2 weeks thereafter. On part A patients are treated with intravenous Avelumab alone and on part B patients receive Avelumab in combination with MRI-guided LITT. Part A completed enrollment without DLT. Enrollment on part B began in October 2018. A Simon minimax two-stage design is being used for efficacy. Toxicity will be scored using the NCI-CTCAE 4.03 criteria. Blood samples and tumor tissue will be collected for correlative studies. Quantification of the changes in inflammatory and immunosuppressive profiles across time points for patients receiving treatment with Avelumab will be obtained. This information will instruct future immunotherapy approaches to treat GBM and the rational for those combinations. Clinical trial information: NCT03341806.

Prediction of recurrent glioblastoma after laser interstitial thermal therapy: The role of diffusion imaging.

BackgroundEvaluate the utility of diffusion-weighted imaging (DWI) for the assessment of local recurrence of glioblastoma (GBM) on imaging performed 24 h following MRI-guided laser interstitial thermal therapy (LITT). We hypothesize that microscopic peritumoral infiltration correlates with early subtle variations on DWI images and apparent diffusion coefficient (ADC) maps.MethodsOf 64 patients with GBM treated with LITT, 39 had MRI scans within 24 h after undergoing LITT. Patterns on DWI images and ADC maps 24 h following LITT were correlated with areas of future GBM recurrence identified through coregistration of subsequent MRI examinations. In the areas of suspected recurrence within the periphery of post-LITT lesions, signal intensity values on ADC maps were recorded and compared with the remaining peritumoral ring.ResultsThirty-nine patients with GBM met the inclusion criteria. For predicting recurrent GBM, areas of decreased DWI signal and increased signal on ADC maps within the expected peritumoral ring of restricted diffusion identified 24 h following LITT showed 86.1% sensitivity, 75.2% specificity, and high correlation (r = 0.53) with future areas of GBM recurrence (P < .01). Areas of future recurrence demonstrated a 37% increase in the ADC value (P < .001), compared with findings in the surrounding treated peritumoral region. A significantly greater area under the receiver operating characteristics curve was determined for ADC values (P < .01).ConclusionsDWI obtained 24 h following LITT can help predict the location of GBM recurrence months before the development of abnormal enhancement. This may alter future treatment planning, perhaps suggesting areas that may be targeted for additional therapy.

Laser interstitial thermal therapy in drug-resistant epilepsy.

MRI-guided stereotactic laser interstitial thermal therapy (LiTT) has been utilized in the surgical treatment of discrete, small epileptogenic lesions. This review summarizes the current literature and addresses the clinical application of this technique. LiTT has the potential to reduce the morbidity and discomfort of epilepsy surgery. Review of data from retrospective, uncontrolled studies suggests that LiTT may offer benefit when treating drug-resistant epilepsy because of mesial temporal sclerosis, hypothalamic hamartoma, cavernous hemangioma, and small cortical dysplasias and malformations. It is now being offered as initial therapy in place of anterior temporal lobectomy in many centers, and a prospective study is underway to compare it with historical temporal lobectomy reports. LiTT appears promising and has potential for reduced morbidity and improved tolerability compared with open surgery. Studies must be done to compare efficacy and safety of LiTT with open surgery, and further investigation is needed to optimize this technique.

Postoperative Outcomes of Magnetic Resonance Imaging (MRI)-Guided Laser Interstitial Thermal Therapy (LITT) in the Treatment of Drug-Resistant Epilepsy: A Meta-Analysis.

BackgroundDrug-resistant epilepsy is a common neurological disease in adults and children. This study aimed to undertake a systematic review of the literature with meta-analysis of the data from published studies to assess the effectiveness of magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (LITT) in treatment-resistant epilepsy.Material/MethodsThe study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, MEDLINE, and EMBASE databases were systematically searched for indexed publications in the English language up to May 2018. Data on the prevalence, outcome using the Engel Epilepsy Surgery Outcome Scale (Class I to IV), and postoperative complications were analyzed with 95% confidence intervals (CIs). The Methodological Index for Non-Randomized Studies (MINORS) was used to assess the risk of bias in the included studies.ResultsSixteen published studies that included a total of 269 patients with treatment resistant epilepsy were identified. The prevalence of Engel Class I, II, III and IV were 61% (95% CI, 0.54–0.68; I2=14.5%; P=0.302), 12% (95% CI, 0.07–0.16; I2=86.8%; P=0.000), 16% (95% CI, 0.10–0.22; I2=3.0%; P=0.397), and 15% (95% CI, 0.08–0.22; I2=13.2%; P=0.330), respectively. The prevalence of postoperative complications was 24% (95% CI, 0.16–0.32; I2=0%; P=0.629).ConclusionsMeta-analysis of data from 16 studies that included 269 patients with treatment-resistant epilepsy showed that MRI-guided LITT significantly reduced the frequency of seizures and reduced postoperative complications, supporting the safety and effectiveness of MRI-guided LITT in the treatment of drug-resistant epilepsy.

Validation of corpus callosotomy after laser interstitial thermal therapy: a multimodal approach.

Disconnection of the cerebral hemispheres by corpus callosotomy (CC) is an established means to palliate refractory generalized epilepsy. Laser interstitial thermal therapy (LITT) is gaining acceptance as a minimally invasive approach to treating epilepsy, but this method has not been evaluated in clinical series using established methodologies to assess connectivity. The goal in this study was to demonstrate the safety and feasibility of MRI-guided LITT for CC and to assess disconnection by using electrophysiology- and imaging-based methods. Retrospective chart and imaging review was performed in 5 patients undergoing LITT callosotomy at a single center. Diffusion tensor imaging and resting functional MRI were performed in all patients to assess anatomical and functional connectivity. In 3 patients undergoing simultaneous intracranial electroencephalography monitoring, corticocortical evoked potentials and resting electrocorticography were used to assess electrophysiological correlates. All patients had generalized or multifocal seizure onsets. Three patients with preoperative evidence for possible lateralization underwent stereoelectroencephalography depth electrode implantation during the perioperative period. LITT ablation of the anterior corpus callosum was completed in a single procedure in 4 patients. One complication involving misplaced devices required a second procedure. Adequacy of the anterior callosotomy was confirmed using contrast-enhanced MRI and diffusion tensor imaging. Resting functional MRI, corticocortical evoked potentials, and resting electrocorticography demonstrated functional disconnection of the hemispheres. Postcallosotomy monitoring revealed lateralization of the seizures in all 3 patients with preoperatively suspected occult lateralization. Four of 5 patients experienced > 80% reduction in generalized seizure frequency. Two patients undergoing subsequent focal resection are free of clinical seizures at 2 years. One patient developed a 9-mm intraparenchymal hematoma at the site of entry and continued to have seizures after the procedure. MRI-guided LITT provides an effective minimally invasive alternative method for CC in the treatment of seizures associated with drop attacks, bilaterally synchronous onset, and rapid secondary generalization. The disconnection is confirmed using anatomical and functional neuroimaging and electrophysiological measures.

Management of Intracranial Metastatic Disease With Laser Interstitial Thermal Therapy.

Treatment approaches for metastatic brain tumors continue to evolve, with increasing recent emphasis on focal therapies whenever possible. MRI-guided Laser Interstitial Thermal Therapy (LITT) is a minimally invasive surgical option that has broadened the capability of the neurosurgeon in treating difficult-to-treat intracranial lesions. This technology uses image-guided delivery of laser to the target lesion to generate heat and thereby ablate pathological tissue and has expanded the neurosurgical armamentarium for surgical treatment of brain metastases. In this study, we describe the indications for LITT in the management of intracranial metastatic disease and report our institutional experience with LITT.