BACKGROUND: The surgical treatment of brain tumors has developed over time, offering customized strategies for patients and their specific lesions. One of the most recent advances in pediatric neuro-oncological surgery is laser interstitial thermal therapy (LITT). However, its effectiveness and indications are still being evaluated. The aim of this work is to review the current literature on LITT for pediatric low-grade gliomas (pLGG) and evaluate our initial results in this context.
METHODS: We retrospectively reviewed our pediatric neurosurgery database for patients who received LITT treatment between November 2019 and December 2023. We collected data on the indications for LITT, technical issues during the procedure, and clinical and radiological follow-up.
RESULTS: Three patients underwent 5 LITT procedures for pLGG. The lesion was thalamo-peduncular in one patient, cingulate in one, and deep parietal in one patient. Two patients had a previous open resection done and were diagnosed with pLGG. One patient underwent a stereotaxic biopsy during the LITT procedure that was non-diagnostic. The same patient underwent a later open resection of the tumor in the cingulate gyrus. There were no surgical complications and all patients were discharged home on the first post-operative day. The follow-up period was between 20 and 40 months. Radiological follow-up showed a progressive reduction of the tumor in patients with LGG.
CONCLUSIONS: Laser interstitial thermal therapy is a minimally invasive treatment that shows promise in treating deep-seated pLGG in children. The treatment has demonstrated a reduction in tumor volume, and the positive results continue over time. LITT can be used as an alternative treatment for tumors located in areas that are difficult to access surgically or in cases where other standard treatment options have failed.

We present the unique case of a 60-year-old female with neurofibromatosis type 1 (NF1) who underwent laser interstitial thermal therapy (LITT) for metastatic malignant peripheral nerve sheath tumor (MPNST) of the brain. She presented to the emergency room complaining of one week of dysarthria and facial droop. An MRI of the brain demonstrated a homogeneously enhancing left frontal mass; although rare, given her history of pulmonary MPNST, brain invasion was considered likely. No generally accepted guidelines for the treatment of MPNST with cerebral metastases exist; however, LITT was chosen due to tumor morphology and proximity to eloquent brain structures. She did not experience any new or worsening neurological deficits post-operatively. Post-ablation MRI showed white matter edema surrounding the lesion, which is consistent with previously reported cases. This case illustrates the use of LITT for cytoreduction for rare brain metastases located near eloquent brain structures.

OBJECTIVE: Meningiomas are the most common primary brain tumors in adults and a subset are aggressive lesions resistant to standard therapies. Laser interstitial thermal therapy (LITT) has been successfully applied to other brain tumors, and recent work aims to explore the safety and long-term outcome experiences of LITT for both new and recurrent meningiomas. The authors\' objective was to report safety and outcomes data of the largest cohort of LITT-treated meningioma patients to date.
METHODS: Eight United States-based hospitals enrolled patients with meningioma in the Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN) prospective multicenter registry and/or contributed additional retrospective enrollments for this cohort study. Demographic, procedural, safety, and outcomes data were collected and analyzed using standard statistical methods.
RESULTS: Twenty adult patients (12 prospective and 8 retrospective) with LITT-targeted meningiomas were accrued. Patients underwent LITT for new (6 patients) and recurrent (14 patients) tumors (ranging from the 1st to 12th recurrence). The 30-day complication rate was 10%. Twenty percent of patients (4/20) had exhausted all other treatment options. Median length of follow-up was 1.3 years. One-third of new (2/6) and one-half of recurrent (7/14) meningiomas had disease progression during follow-up. One-year estimated local control (LC), progression-free survival, and overall survival rates were 55.3%, 48.4%, and 86.3%, respectively. In the 12 patients who had ≥ 91% ablative coverage, 1-year estimated LC was 61.4%. The complication rate was 10% (2/20), with 1 complication being transient and resolving postoperatively.
CONCLUSIONS: This cohort study supports the safety of the procedure for this tumor type. LITT can offer a much-needed treatment option, especially for patients with multiply recurrent meningiomas who have limited remaining alternatives.

BACKGROUND: Ionizing radiation and alkylating chemotherapies increase secondary malignancy risk in patients with cancer predisposition syndromes (CPSs), such as Li-Fraumeni syndrome. Laser interstitial thermal therapy (LITT) is a minimally invasive ablation technique that has not been associated with mutagenic risks. We describe the case of a child with LFS and a history of treated choroid plexus carcinoma (CPC) who developed a second primary glial tumor that was safely treated with magnetic resonance imaging (MRI)-guided LITT.
METHODS: A 4-year-old male with left parietal World Health Organization grade III CPC associated with a TP53 germline mutation was evaluated. The patient underwent neoadjuvant platinum-based chemotherapy before near-total resection, followed by 131I-8H9 immunotherapy and 30 fractions of 54-Gy proton radiotherapy. He remained without evidence of disease for 2 years before developing a slow-growing mass adjacent to the left frontal ventricular horn. Stereotactic biopsy revealed a glial neoplasm. Given the nonsuperficial location and focality of the lesion, MRI-guided LITT was performed for ablative therapy. There were no complications, and 2 years of surveillance revealed continued retraction of the ablated tumor focus and no subsequent disease.
CONCLUSIONS: Alternatives to mutagenic therapies for brain tumors should be explored for patients with CPS. LITT paired with imaging surveillance is a logical strategy to ensure durable outcomes and mitigate treatment-related secondary neoplasms.

BACKGROUND: Ependymoma is the third most common pediatric brain tumor that can present with headaches, cranial nerve deficits, nausea, vomiting, and ataxia. Current treatment is maximal safe resection followed by radiation therapy. More recently, laser interstitial thermal therapy (LITT) has become an alternative to traditional resection. In this report, the authors describe the utilization of a single-use, patient-specific stereotactic platform for the treatment of supratentorial ependymoma with LITT.
METHODS: A 2-year-old female had a complex history of supratentorial ependymoma after multiple craniotomies for repeated tumor progression and ventriculoperitoneal shunt placement. Imaging demonstrated an enlarging, complex, enhancing mass in the right occipital region. LITT was decided on for treatment. Given the thinness of the patient\'s skull, which precluded traditional means of stereotaxy, the authors elected to use a personalized stereotactic platform. Immediate postoperative imaging captured complete laser ablation of the tumor, with long-term imaging demonstrating a decreased tumor size.
CONCLUSIONS: Individualized stereotactic platforms are increasingly used in adult populations, but pediatric use continues to be infrequent. In this report, the authors present the youngest reported case using a personalized stereotactic platform and show the effectiveness of this system for performing LITT in the youngest of populations with very thin skulls.

Responsive neurostimulation (RNS) is a valuable tool in the diagnosis and treatment of medication refractory epilepsy (MRE) and provides clinicians with better insights into patients\' seizure patterns. In this case illustration, we present a patient with bilateral hippocampal RNS for presumed bilateral mesial temporal lobe epilepsy. The patient subsequently underwent a right sided LITT amygdalohippocampotomy based upon chronic RNS data revealing predominance of seizures from that side. Analyzing electrocorticography (ECOG) from the RNS system, we identified the frequency of high amplitude discharges recorded from the left hippocampal lead pre- and post- right LITT amygdalohippocampotomy. A reduction in contralateral interictal epileptiform activity was observed through RNS recordings over a two-year period, suggesting the potential dependency of the contralateral activity on the primary epileptogenic zone. These findings suggest that early targeted surgical resection or laser ablation by leveraging RNS data can potentially impede the progression of dependent epileptiform activity and may aid in preserving neurocognitive networks. RNS recordings are essential in shaping further management decisions for our patient with a presumed bitemporal epilepsy.

BACKGROUND: Thalamic gliomas pose a particular therapeutic challenge as complete resection is rarely achieved due to the deep and eloquent location. Laser interstitial thermal therapy (LITT) may provide a valuable management option for deep-seated gliomas that are not accessible with open surgery.
METHODS: A 57-year-old woman presented with a rapidly progressive large thalamic glioblastoma. Opting for full ablation, we selected a challenging trajectory to maximize the possibility of full ablation. At 2.4 cm in diameter, the tumour was larger than recommended for LITT; nevertheless, three laser ablations along a single trajectory resulted in macroscopic ablation without complications. Adjuvant radio-chemotherapy was started soon after surgery without radiological recurrence 1.5 years after the initial surgery.
CONCLUSIONS: This case demonstrates the potential when thalamic tumours are managed with timely LITT treatment and meticulous trajectory planning. Moreover, it highlights the need for close interdisciplinary management with neurosurgeons, neuropathologists, neuroradiologists, and neurooncologists.

Primitive neuroectodermal tumors of the central nervous system, or CNS neuroblastoma, are rare neoplasms in children. Recently, methylation profiling enabled the discovery of four distinct entities of these tumors. The current treatment paradigm involves surgical resection followed by chemotherapy and radiation. However, upfront surgical resection carries high surgical morbidity in this patient population due to their young age, tumor vascularity, and often deep location in the brain. We report a case of CNS neuroblastoma that can be successfully treated with neoadjuvant chemotherapy followed by minimally invasive laser interstitial thermal therapy and radiation. The patient has complete treatment with no evidence of recurrence at one year follow-up. This case illustrates a potential paradigm shift in the treatment of these rare tumors can be treated using minimally invasive surgical approach to achieve a favorable outcome.

In patients with treatment-refractory temporal lobe epilepsy (TLE), a single stereotactic laser interstitial thermotherapy (LITT) procedure is sometimes insufficient to ablate epileptogenic tissue, particularly the medial structures often implicated in TLE. In patients with seizure recurrence after initial ablation, the extent to which a second ablation may achieve improved seizure outcomes is uncertain. The objective of this study was to investigate the feasibility and potential efficacy of repeat LITT amygdalohippocampotomy as a worthwhile strategy for intractable temporal lobe epilepsy by quantifying changes to targeted mesial temporal lobe structures and seizure outcomes.
Patients who underwent two LITT procedures for drug-resistant mesial TLE at our institution were included in the study. Lesion volumes for both procedures were calculated by comparing post-ablation intraoperative sequences to preoperative anatomy. Clinical outcomes after the initial procedure and repeat procedure were classified according to Engel scores.
Five consecutive patients were included in this retrospective case series: 3 with right- and 2 with left-sided TLE. The median interval between LITT procedures was 294 days (range: 227-1918). After the first LITT, 3 patients experienced class III outcomes, 1 experienced a class IV, and 1 experienced a class IB outcome. All patients achieved increased seizure freedom after a second procedure, with class I outcomes (3 IA, 2 IB).
Repeat LITT may be sufficient to achieve satisfactory seizure outcomes in some individuals who might otherwise be considered for more aggressive resection or palliative neuromodulation. A larger study to establish the potential value of repeat LITT amygdalohippocampotomy vs. other re-operation strategies for persistent, intractable temporal lobe epilepsy is worth pursuing.

UNASSIGNED: Meningiomas are the most common primary central nervous system neoplasm in the United States. While the majority of meningiomas are benign, the World Health Organization (WHO) Grade I tumors, a not-insignificant proportion of tumors are in anatomically complex locations or demonstrate more aggressive phenotypes, presenting a challenge for local disease control with surgery and radiation. Laser interstitial thermal therapy (LITT) consists of stereotactic delivery of laser light for tumor ablation and is minimally invasive, requiring implantation of a laser fiber through a cranial burr hole. Herein, we demonstrate the first use of this technology in a progressive atypical sphenoid wing meningioma for a previously resected and irradiated tumor.
UNASSIGNED: A 47-year-old female was diagnosed with a left-sided atypical meningioma, the WHO 2, of the sphenoid wing following acute worsening of bitemporal headache and dizziness. Given neurovascular involvement, a subtotal resection was performed, followed by stereotactic radiosurgery. Following progression 9 months from resection, the patient elected to proceed with LITT. The patient\'s postoperative course was uncomplicated and she remains progression free at 24 months following LITT.
UNASSIGNED: We present the first use of LITT for a sphenoid wing meningioma documented in the literature, which demonstrated enhanced disease control for a lesion that was refractory to both surgery and radiation. LITT could represent an additional option for local control of progressive meningiomas, even in locations that are challenging to access surgically. More evidence is needed regarding the technical nuances of LITT for lesions of the skull base.