MRI-guided Laser Interstitial Thermal Therapy Research Articles

Stereotactic EEG-guided laser interstitial thermal therapy for mesial temporal lobe epilepsy

ObjectiveTo determine the outcomes of combined stereo-electroencephalography-guided and MRI-guided stereotactic laser interstitial thermal therapy (LITT) in the treatment of patients with drug-resistant mesial temporal lobe epilepsy (mTLE).MethodsWe prospectively assessed the...

Magnetic resonance imaging-guided laser interstitial thermal therapy as treatment for intractable insular epilepsy in children.

OBJECTIVE Seizure onset within the insula is increasingly recognized as a cause of intractable epilepsy. Surgery within the insula is difficult, with considerable risks, given the rich vascular supply and location near critical cortex. MRI-guided laser interstitial thermal therapy (LiTT) provides an attractive treatment option for insular epilepsy, allowing direct ablation of abnormal tissue while sparing nearby normal cortex. Herein, the authors describe their experience using this technique in a large cohort of children undergoing treatment of intractable localization-related epilepsy of insular onset. METHODS The combined epilepsy surgery database of Cook Children's Medical Center and Dell Children's Hospital was queried for all cases of insular onset epilepsy treated with LiTT. Patients without at least 6 months of follow-up data and cases preoperatively designated as palliative were excluded. Patient demographics, presurgical evaluation, surgical plan, and outcome were collected from patient charts and described. RESULTS Twenty patients (mean age 12.8 years, range 6.1-18.6 years) underwent a total of 24 LiTT procedures; 70% of these patients had normal findings on MRI. Patients underwent a mean follow-up of 20.4 months after their last surgery (range 7-39 months), with 10 (50%) in Engel Class I, 1 (5%) in Engel Class II, 5 (25%) in Engel Class III, and 4 (20%) in Engel Class IV at last follow-up. Patients were discharged within 24 hours of the procedure in 15 (63%) cases, in 48 hours in 6 (24%) cases, and in more than 48 hours in the remaining cases. Adverse functional effects were experienced following 7 (29%) of the procedures: mild hemiparesis after 6 procedures (all patients experienced complete resolution or had minimal residual dysfunction by 6 months), and expressive language dysfunction after 1 procedure (resolved by 3 months). CONCLUSIONS To their knowledge, the authors present the largest cohort of pediatric patients undergoing insular surgery for treatment of intractable epilepsy. The patient outcomes suggest that LiTT can successfully treat intractable seizures originating within the insula and offers an attractive alternative to open resection. This is the first description of LiTT applied to insular epilepsy and represents one of only a few series describing the use of LiTT in children. The results indicate that seizure reduction after LiTT compares favorably to that after conventional open surgical techniques.

Laser Interstitial Thermal Therapy for Epilepsy.

MRI-guided laser interstitial thermal therapy (MgLiTT) uses a narrow diameter cannula to stereotactically target and heat deeper cerebral structures. This technique produces a precise lesion in the brain with great reliability because the localized tissue temperature change is monitored in real time. Because MgLiTT minimizes injury to surrounding brain, it appears to have a lower risk of affecting normal neurological function, and because it is done through a burr hole, there is less operative risk, less discomfort, and shorter hospitalizations. It is FDA approved for soft tissue ablation and is being increasingly applied to the surgical treatment of epilepsy, especially when seizures arise from deeper structures such as the hippocampus, amygdala, or discrete dysplastic tissue such as hypothalamic hamartomas. Mesial temporal epilepsy is the most frequently encountered surgically remedial epilepsy suitable for MgLiTT, particularly when there is unilateral hippocampal sclerosis. There is emerging evidence that it can be effective for eliminating seizures in this type of epilepsy, and that it has a lower risk of cognitive deficits than anterior temporal lobectomy.

MRI-guided laser interstitial thermal therapy for the treatment of low-grade gliomas in children: a case-series review, description of the current technologies and perspectives.

Pediatric low-grade gliomas (LGGs) account for approximately half of all pediatric central nervous system tumors. The low-grade gliomas' first line of treatment is gross total resection. However, when gross total resection is not possible, options for adjuvant therapy are limited. MRI-guided laser ablation (magnetic resonance-guided laser interstitial thermal therapy (MRgLITT)) offers a new option for treatment in selected cases. We present a description of the current MRgLITT technology and an exemplary case-series review of our experience in its use in LGGs. A 19-month-old male was referred to the pediatric neurosurgery clinic with an incidental left temporal lesion discovered on a prenatal ultrasound. An MRI of the brain revealed a diffuse mesial temporal lesion. Electroencephalogram (EEG) showed generalized activity arising from the lesion. The patient underwent a navigation-guided biopsy then, two bolts were secured to the skull, and laser ablation was performed with intraoperative MR guidance. Pathology was consistent with ganglioglioma. Follow-up images 13months after ablation showed a significant volumetric reduction in size of the tumor. It is important to achieve maximal resection of low-grade gliomas in children, lessening the need for adjuvant chemotherapy and radiotherapy, while minimizing the length of hospital stay and disruption to the child's life. Of our nine LGGs patients treated with this technology, six had undergone previous surgery and MRgLITT proved itself to be a safe surgical treatment option to achieve further cytoreduction. While most of the cases are pilocytic astrocytomas, the location of the tumors was surgically challenging. Eight of the nine cases required a single trajectory-laser-while our case example requires two lasers. Only a case of a midbrain-thalamic tumor presented a post-ablation significant brain edema as perioperative complication [1]. Eight of the nine tumors did not require any coadjuvant therapy or further surgical treatment to date. MRIgLITT is a successful option for treatment for selected de novo or recurrent low-grade gliomas in children. It can be combined with other therapies offering the advantages of a minimally invasive procedure. LITT may be added to the current pediatric neuro-oncology protocols, but larger prospective series are needed to show the effectiveness of LITT and to standardize indications and protocols.

Emerging surgical therapies in the treatment of pediatric epilepsy

In the approximately 1% of children affected by epilepsy, pharmacoresistance and early age of seizure onset are strongly correlated with poor cognitive outcomes, depression, anxiety, developmental delay, and impaired activities of daily living. These children often require multiple surgical procedures, including invasive diagnostic procedures with intracranial electrodes to identify the seizure-onset zone. The recent development of minimally invasive surgical techniques, including stereotactic electroencephalography (SEEG) and MRI-guided laser interstitial thermal therapy (MRgLITT), and new applications of neurostimulation, such as responsive neurostimulation (RNS), are quickly changing the landscape of the surgical management of pediatric epilepsy. In this review, the authors discuss these various technologies, their current applications, and limitations in the treatment of pediatric drug-resistant epilepsy, as well as areas for future research. The development of minimally invasive diagnostic and ablative surgical techniques together with new paradigms in neurostimulation hold vast potential to improve the efficacy and reduce the morbidity of the surgical management of children with drug-resistant epilepsy.

Hyperthermic Laser Ablation of Recurrent Glioblastoma Leads to Temporary Disruption of the Peritumoral Blood Brain Barrier.

BackgroundPoor central nervous system penetration of cytotoxic drugs due to the blood brain barrier (BBB) is a major limiting factor in the treatment of brain tumors. Most recurrent glioblastomas (GBM) occur within the peritumoral region. In this study, we describe a hyperthemic method to induce temporary disruption of the peritumoral BBB that can potentially be used to enhance drug delivery.MethodsTwenty patients with probable recurrent GBM were enrolled in this study. Fourteen patients were evaluable. MRI-guided laser interstitial thermal therapy was applied to achieve both tumor cytoreduction and disruption of the peritumoral BBB. To determine the degree and timing of peritumoral BBB disruption, dynamic contrast-enhancement brain MRI was used to calculate the vascular transfer constant (Ktrans) in the peritumoral region as direct measures of BBB permeability before and after laser ablation. Serum levels of brain-specific enolase, also known as neuron-specific enolase, were also measured and used as an independent quantification of BBB disruption.ResultsIn all 14 evaluable patients, Ktrans levels peaked immediately post laser ablation, followed by a gradual decline over the following 4 weeks. Serum BSE concentrations increased shortly after laser ablation and peaked in 1–3 weeks before decreasing to baseline by 6 weeks.ConclusionsThe data from our pilot research support that disruption of the peritumoral BBB was induced by hyperthemia with the peak of high permeability occurring within 1–2 weeks after laser ablation and resolving by 4–6 weeks. This provides a therapeutic window of opportunity during which delivery of BBB-impermeant therapeutic agents may be enhanced.Trial RegistrationClinicalTrials.gov NCT01851733

Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy.

To describe mesial temporal lobe ablated volumes, verbal memory, and surgical outcomes in patients with medically intractable mesial temporal lobe epilepsy (mTLE) treated with magnetic resonance imaging (MRI)-guided stereotactic laser interstitial thermal therapy (LiTT). We prospectively tracked seizure outcome in 20 patients at Thomas Jefferson University Hospital with drug-resistant mTLE who underwent MRI-guided LiTT from December 2011 to December 2014. Surgical outcome was assessed at 6 months, 1 year, 2 years, and at the most recent visit. Volume-based analysis of ablated mesial temporal structures was conducted in 17 patients with mesial temporal sclerosis (MTS) and results were compared between the seizure-free and not seizure-free groups. Following LiTT, proportions of patients who were free of seizures impairing consciousness (including those with auras only) are as follows: 8 of 15 patients (53%, 95% confidence interval [CI] 30.1-75.2%) after 6 months, 4 of 11 patients (36.4%, 95% CI 14.9-64.8%) after 1 year, 3 of 5 patients (60%, 95% CI 22.9-88.4%) at 2-year follow-up. Median follow-up was 13.4 months after LiTT (range 1.3 months to 3.2 years). Seizure outcome after LiTT suggests an all or none response. Four patients had anterior temporal lobectomy (ATL) after LiTT; three are seizure-free. There were no differences in total ablated volume of the amygdalohippocampus complex or individual volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and fusiform gyrus between seizure-free and non-seizure-free patients. Contextual verbal memory performance was preserved after LiTT, although decline in noncontextual memory task scores were noted. We conclude that MRI-guided stereotactic LiTT is a safe alternative to ATL in patients with medically intractable mTLE. Individualized assessment is warranted to determine whether the reduced odds of seizure freedom are worth the reduction in risk, discomfort, and recovery time. Larger prospective studies are needed to confirm our preliminary findings, and to define optimal ablation volume and ideal structures for ablation.

Current Applications of MRI-Guided Laser Interstitial Thermal Therapy in the Treatment of Brain Neoplasms and Epilepsy: A Radiologic and Neurosurgical Overview.

Minimally invasive stereotactic tumor ablation is a viable option for the treatment of benign and malignant intracranial lesions. Although surgical excision constitutes first-line therapy for various brain pathologies, it can cause irreversible neurologic deficits. Additionally, many patients who may benefit from surgery do not qualify as surgical candidates due to multiple comorbidities. Recent advancements in laser interstitial thermal therapy, namely the ability to monitor ablation in real-time under MR imaging, have improved the safety and efficacy of the procedure. MRI-guided laser interstitial thermal therapy is currently used as a minimally invasive treatment for brain metastases, radiation necrosis, glioma, and epilepsy. This article will discuss the principles, suggested indications, complications, and imaging characteristics of MRI-guided laser interstitial thermal therapy as they pertain to the treatment of brain pathology.

Laser induced thermal therapy (LITT) for pediatric brain tumors: case-based review.

Integration of Laser induced thermal therapy (LITT) to magnetic resonance imaging (MRI) have created new options for treating surgically challenging tumors in locations that would otherwise have represented an intrinsic comorbidity by the approach itself. As new applications and variations of the use are discussed, we present a case-based review of the history, development, and subsequent updates of minimally invasive MRI-guided laser interstitial thermal therapy (MRgLITT) ablation in pediatric brain tumors.

MRI-guided laser interstitial thermal therapy of intracranial tumors and epilepsy: State-of-the-art review and a case study from pediatrics

AbstractMRI-guided laser interstitial thermal therapy (MRgLITT) is gaining momentum in neurosurgery and has been described to treat brain metastases, primary tumors and radiation-induced necrosis with an excellent safety profile. LITT has been also used as a minimally invasive alternative to surgical treatment of refractory epilepsy for ablating single epileptogenic foci, such as tumors, hypothalamic hamartomas, cortical dysplasia and mesial temporal sclerosis. Novelty initial experience with multi-foci epileptogenic zones and tuberosclerosis patients is also reported. As new applications for this technology are developing and variations on its use are discussed, we present a review of the current uses and results of the LITT application on brain lesions.

The use of MRI-guided laser-induced thermal ablation for epilepsy

Epilepsy surgery is constantly researching for new options for patients with refractory epilepsy. MRI-guided laser-induced thermal ablation for epilepsy is an exciting new minimally invasive technology with an emerging use for lesionectomy of a variety of epileptogenic focuses (hypothalamic hamartomas, cortical dysplasias, cortical malformations, tubers) or as a disconnection tool allowing a new option of treatment without the hassles of an open surgery. MRI-guided laser interstitial thermal therapy (MRgLITT) is a procedure for destroying tissue-using heat. To deliver this energy in a minimally invasive fashion, a small diameter fiber optic applicator is inserted into the lesion through a keyhole stereotactic procedure. The thermal energy induces damage to intracellular DNA and DNA-binding structures, ultimately leading to cell death. The ablation procedure is supervised by real-time MRI thermal mapping and confirmed by immediate post-ablation T1 or FLAIR MRI images. The present report includes an overview of the development and practice of an MR-guided laser ablation therapy known as MRI-guided laser interstitial thermal therapy (MRgLITT). The role of modern image-guided trajectory planning in MRgLITT will also be discussed, with particular emphasis on the treatment of refractory epilepsy using this novel, minimally invasive technique. MRI-guided laser-induced thermal ablation for epilepsy is an exciting new minimally invasive technology that finds potential new applications every day in the neurosurgical field. It certainly brings a new perspective on the way we practice epilepsy surgery even though long-term results should be properly collected and analyzed.