Laser interstitial thermal therapy for high-grade glioma: a systematic review, meta-analysis, and meta-regression

Neurosurg Focus 59(2):E10, 2025

Laser interstitial thermal therapy (LITT) is a minimally invasive treatment for high-grade glioma (HGG) showing mean overall survival of 11.7 months and progression-free survival of 5.3 months. LITT offers acceptable safety, especially for deep or unresectable tumors, but further randomized studies are needed to confirm long-term efficacy.

• Laser interstitial thermal therapy (LITT) is a minimally invasive treatment for high-grade glioma (HGG), especially in deep-seated or unresectable tumors.

• A systematic review and meta-analysis of 21 studies including 602 patients found mean overall survival (OS) after LITT was 11.74 months and mean progression-free survival (PFS) was 5.3 months.

• 6-, 12-, and 24-month OS rates were 77.0%, 48.9%, and 16.1%; PFS rates were 37.1%, 12.8%, and 4.3%, respectively.

• Permanent postoperative deficits occurred in 5.7% of patients, with higher rates in newly diagnosed HGG than recurrent cases (4.15% vs 0.02%).

• Tumor progression after LITT was observed in about 80% of patients, and overall mortality was 67.7%.

• Deep/unresectable tumors and IDH-wildtype mutations were associated with worse outcomes; smaller tumor size and higher baseline KPS predicted better survival.

• LITT showed acceptable safety and feasibility, but randomized prospective studies are needed to confirm long-term efficacy.

• Common complications included hemiparesis, weakness, and temporary neurological deficits.

Laser interstitial thermal therapy for cavernous malformations: a meta-analysis of individual patient-level data

J Neurosurg 142:1014–1024, 2025

Laser interstitial thermal therapy (LITT) shows promise for treating cavernous malformations, offering high seizure freedom rates and significant CM volume reduction. Immediate neurological deficits are a risk but often transient. Further research is needed for long-term outcomes and safety validation.

Study Objective: Evaluate laser interstitial thermal therapy (LITT) for cavernous malformations (CMs).

Methodology: PRISMA-compliant systematic review and patient-level data meta-analysis.

Patient Demographics: 39 patients, 28 with epilepsy, treated at six centers.

Seizure Freedom Rate: 88% at last follow-up for epilepsy patients.

Immediate Postoperative Deficits: 15.4% experienced transient neurological deficits.

CM Volume Reduction: 73.7% for epileptogenic, 53.8% for nonepileptogenic CMs.

No Perioperative Hemorrhage: No reported hemorrhages during or after procedures.

Study Limitations: Small patient cohort, limited follow-up time.

Predictors of Seizure Freedom: No significant predictors identified.

Adverse Events Analysis: No significant predictors for adverse events post-LITT.

Radiographic Outcomes: No significant differences based on CM location.

Pooled Effect Size Analysis: Frequentist and Bayesian models used for volume reduction estimates.

Future Research Needs: Larger cohorts and longer follow-up required for validation.

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

World Neurosurg. (2024) 192:224-235

Epilepsy surgery offers a vital treatment option for drug-resistant mesial temporal lobe epilepsy, with temporal lobe resection (TLR) and magnetic resonanceguided laser interstitial thermal therapy (MRgLITT) being fundamental interventions.

This meta-analysis specifically examines seizure outcomes at extended follow-up periods exceeding 24 months, visual field deficits as measured by perimetry, and complication rates both overall and categorized based on duration as minor (transient <6 months) or major (persistent >6 months) to inform clinical decision-making.

For seizure freedom, TLR was superior, with 72.5% [65.6%, 78.5%] of patients achieving postoperative seizure freedom compared to 57.1% [51.2%, 62.7%] for MRgLITT (P value <0.01). Visual field deficits were observed in 79.4% [59.5%, 91.0%] of TLR patients and 49.8% [23.6%, 76.0%] of MRgLITT patients, a difference not reaching statistical significance (P value: 0.08). Overall complication rates were 11.4% [7.4%, 17.2%] for TLR and 6.5% [3.3%, 12.3%] for MRgLITT (P value 0.15). Major complications occurred in 2.0% [1.1%, 3.09%] of TLR cases and 2.7% [1.4%, 5.2%] of MRgLITT cases (P value 0.54), while minor complications were significantly more frequent with TLR at 9.9% [6.4%, 15.0%] versus MRgLITT’s 4.1% [1.9%, 8.4%] (P value 0.04). MRgLITT had a more favorable outcome regarding confrontation naming, while more studies are needed regarding verbal memory to be able to draw firm conclusions. TLR provides superior seizure freedom but comes with an increased risk of transient complications. Although there was no statistical significance in visual field deficits, the trend suggests a higher frequency with TLR.

The study’s extensive data analysis, including rigorous sensitivity checks, ensures the robustness of these conclusions, reflecting a comprehensive analysis of the available data at this time point.

The Impact of Extent of Ablation on Survival of Patients With Newly Diagnosed Glioblastoma Treated With Laser Interstitial Thermal Therapy

Neurosurgery 93:427–435, 2023

Upfront laser interstitial thermal therapy (LITT) can be used as part of the treatment paradigm in difficult-to-access newly diagnosed glioblastoma multiforme (ndGBM) cases. The extent of ablation, though, is not routinely quantified; thus, its specific effect on patients’ oncological outcomes is unclear.

OBJECTIVE: To methodically measure the extent of ablation in the cohort of patients with ndGBM and its effect, and other treatment-related parameters, on patients’ progression-free survival (PFS) and overall survival (OS).

METHODS: A retrospective study was conducted on 56 isocitrate dehydrogenase 1/2 wild-type patients with ndGBM treated with upfront LITT between 2011 and 2021. Patient data including demographics, oncological course, and LITTassociated parameters were analyzed.

RESULTS: Patient median age was 62.3 years (31-84), and the median follow-up duration was 11.4 months. As expected, the subgroup of patients receiving full chemoradiation was found to have the most beneficial PFS and OS (n = 34). Further analysis showed that 10 of them underwent near-total ablation and had a significantly improved PFS (10.3 months) and OS (22.7 months). Notably, 84% excess ablation was detected which was not related to a higher rate of neurological deficits. Tumor volume was also found to influence PFS and OS, but it was not possible to further corroborate this finding because of low numbers.

CONCLUSION: This study presents data analysis of the largest series of ndGBM treated with upfront LITT. Near-total ablation was shown to significantly benefit patients’ PFS and OS. Importantly, it was shown to be safe, even in cases of excess ablation and therefore could be considered when using this modality to treat ndGBM.

Laser interstitial thermal therapy in the treatment of brain metastases: the relationship between changes in postoperative magnetic resonance imaging characteristics and tumor recurrence

Acta Neurochirurgica (2023) 165:1379–1387

Laser interstitial thermal therapy (LITT) has been used to treat brain metastases (BMs) in several countries, and its safety and effectiveness have been confirmed. In most cases, magnetic resonance imaging (MRI) reveals an increase in tumor volume with an enhanced margin after LITT. However, little is known about the relationship between this MRI change and tumor recurrence.

Objective We report the first case series of BMs treated by LITT in China to evaluate the clinical characteristics and predictive factors of tumor recurrence.

Material and methods Patients with less than four brain metastatic lesions and a Karnofsky performance status (KPS) > 70 were eligible for study inclusion. Standard LITT procedures were performed, and a follow-up MRI was performed to analyze the radiographic changes, especially the volume ratio of the enhanced margin and the whole lesion on MRI at 30 days postoperatively. All the volume-related data were delineated and calculated using 3D Slicer software. Related predictors were also collected to evaluate the correlation with local tumor control.

Results Eighteen patients with nineteen lesions were enrolled for treatment and follow-up. Primary tumor histology included pulmonary carcinoma (n = 11) and breast cancer (n = 4). On average, the tumor size measured 3.01 cm3 (range, 0.40–7.40 cm3), the total ablation time was 13.58 min (range, 2.88–37.15 min), and the complete ablation rate was 92.4% (range, 29.2–100%). Comparing 3s0-day follow-up MRI results with preoperative MRI findings, 18 lesions showed a 2.28-fold (range, 1.21–4.88) volume increase; all the lesions displayed an enhanced component with a volume ratio of 42.35% (range, 10.14–100%). Five patients experienced tumor recurrence, and the local tumor control rates at 90 days and 180 days of followup were 68.4% and 66.7%, respectively. Univariate analysis indicated that the primary tumor, ablation rate, and enhanced volume ratio (EVR) > 40% in the 30-day MRI were associated with tumor recurrence, whereas multivariate analysis showed that only EVR > 40% was a predictive factor of local control.

Conclusion LITT is a minimally invasive method used to ablate brain metastases which can be used as the first-line treatment for BM patients under certain indications. After LITT, most tumors showed volume enlargement on the 30-day MRI scan, and EVR > 40% on the 30-day MRI may indicate late tumor recurrence.

Laser interstitial thermal therapy using the Leksell Stereotactic System and a diagnostic MRI suite

Acta Neurochirurgica (2023) 165:549–554

Laser interstitial thermal therapy (LITT) is a stereotactic neurosurgical procedure used to treat neoplastic and epileptogenic lesions in the brain. A variety of advanced technological instruments such as frameless navigation systems, robotics, and intraoperative MRI are often described in this context, although the surgical procedure can also be performed using a standard stereotactic setup and a diagnostic MRI suite.

Methods We report on our experience and a surgical technique using a Leksell stereotactic frame and a diagnostic MRI suite to perform LITT.

Conclusion LITT can be safely performed using the Leksell frame and a diagnostic MRI suite, making the technique available even to neuro-oncology centers without advanced technological setup.

Laser Interstitial Thermal Therapy for First-Line Treatment of Surgically Accessible Recurrent Glioblastoma: Outcomes Compared With a Surgical Cohort

Neurosurgery 91:701–709, 2022

Laser interstitial thermal therapy (LITT) for glioblastoma (GBM) has been reserved for poor surgical candidates and deep “inoperable” lesions. We present the first reported series of LITT for surgically accessible recurrent GBM (rGBM) that would otherwise be treated with surgical resection.

OBJECTIVE: To evaluate the use of LITT for unifocal, lobar, first-time rGBM compared with a similar surgical cohort.

METHODS: A retrospective institutional database was used to identify patients with unifocal, lobar, first-time rGBM who underwent LITT or resection between 2013 and 2020. Clinical and volumetric lesional characteristics were compared between cohorts. Subgroup analysis of patients with lesions ≤20 cm 3 was also completed. Primary outcomes were overall survival and progression-free survival.

RESULTS: Of the 744 patients with rGBM treated from 2013 to 2020, a LITT cohort of 17 patients were compared with 23 similar surgical patients. There were no differences in baseline characteristics, although lesions were larger in the surgical cohort (7.54 vs 4.37 cm3 , P = .017). Despite differences in lesion size, both cohorts had similar extents of ablation/resection (90.7% vs 95.1%, P = .739). Overall survival (14.1 vs 13.8 months, P = .578) and progression-free survival (3.7 vs 3.3 months, P = 0. 495) were similar. LITT patients had significantly shorter hospital stays (2.2 vs 3.0 days, P = .004). Subgroup analysis of patients with lesions ≤20 cm 3 showed similar outcomes, with LITT allowing for significantly shorter hospital stays.

CONCLUSION: We found no difference in survival outcomes or morbidity between LITT and repeat surgery for surgically accessible rGBM while LITT resulted in shorter hospital stays and more efficient postoperative care.

 

 

Acute Postoperative Seizures and Engel Class Outcome at 1 Year Postselective Laser Amygdalohippocampal Ablation for Mesial Temporal Lobe Epilepsy

Neurosurgery 91:347–354, 2022

MRI-guided laser interstitial thermal therapy (MRgLITT) for mesial temporal lobe epilepsy is a safe, minimally invasive alternative to traditional surgical approaches. Prognostic factors associated with efficacy are debated; preoperative epilepsy duration and semiology seem to be important variables.

OBJECTIVE: To determine whether acute postoperative seizure (APOS) after MRgLITT for mesial temporal lobe epilepsy is associated with seizure freedom/Engel class outcome at 1 year.

METHODS: A single-institution retrospective study including adults undergoing first time MRgLITT for mesial temporal lobe epilepsy (2010-2019) with ≥1-year follow-up. Preoperative data included sex, epilepsy duration, number of antiepileptics attempted, weekly seizure frequency, seizure semiology, and radiographically verified anatomic lesion at seizure focus. Postoperative data included clinical detection of APOS within 7 days postoperatively, and immediate amygdala, hippocampal, entorhinal, and parahippocampal residual volumes determined using quantitative imaging postprocessing. Primary outcome was seizure freedom/Engel classification 1 year postoperatively.

RESULTS: Of 116 patients, 53%(n = 61) were female, with an average epilepsy duration of 21 (±14) years, average 6 failed antiepileptics (±3), and weekly seizure frequency of 5. APOS was associated with worse Engel class (P = .010), conferring 6.3 times greater odds of having no improvement vs achieving seizure freedom at 1 year. Residual amygdala, hippocampal, entorhinal, and parahippocampal volumes were not statistically significant prognostic factors.

CONCLUSION: APOS was associated with a lower chance of seizure freedom at 1 year post-MRgLITT for mesial temporal lobe epilepsy. Amygdala, hippocampal, entorhinal, and parahippocampal residual volumes after ablation were not significant prognostic factors.

 

Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN): 12-Month Outcomes and Quality of Life After Brain Tumor Ablation

Neurosurgery 87:E338–E346, 2020

Laser Ablation of Abnormal Neurological Tissue using Robotic NeuroBlate System (LAANTERN) is an ongoing multicenter prospective NeuroBlate (Monteris Medical) LITT (laser interstitial thermal therapy) registry collecting real-world outcomes and quality- of-life (QoL) data.

OBJECTIVE: To compare 12-mo outcomes from all subjects undergoing LITT for intracranial tumors/neoplasms.

METHODS: Demographics, intraprocedural data, adverse events, QoL, hospitalizations, health economics, and survival data are collected; standard data management and monitoring occur.

RESULTS: A total of 14 centers enrolled 223 subjects; the median follow-up was 223 d. There were 119 (53.4%) females and 104 (46.6%) males. The median age was 54.3 yr (range 3-86) and 72.6% had at least 1 baseline comorbidity. The median baseline Karnofsky Performance Score (KPS) was 90. Of the ablated tumors, 131 were primary and 92 were metastatic. Most patients with primary tumors had high-grade gliomas (80.9%). Patients with metastatic cancer had recurrence (50.6%) or radiation necrosis (40%). The median postprocedure hospital stay was 33.4 h (12.7-733.4). The 1-yr estimated survival rate was 73%, and this was not impacted by disease etiology. Patient-reported QoL as assessed by the Functional Assessment of Cancer Therapy-Brain was stabilized postprocedure. KPS declined by an average of 5.7 to 10.5 points postprocedure; however, 50.5% had stabilized/improved KPS at 6 mo. There were no significant differences in KPS or QoL between patients with metastatic vs primary tumors.

CONCLUSION: Results from the ongoing LAANTERN registry demonstrate that LITT stabi- lizes and improves QoL from baseline levels in a malignant brain tumor patient population with high rates of comorbidities. Overall survival was better than anticipated for a real- world registry and comparative to published literature.

Predictors of Local Control of Brain Metastasis TreatedWith Laser Interstitial Thermal Therapy

Neurosurgery 87:112–122, 2020

Laser Interstitial Thermal Therapy (LITT) has been used to treat recurrent brain metastasis after stereotactic radiosurgery (SRS). Little is known about how best to assess the efficacy of treatment, specifically the ability of LITT to control local tumor progression post-SRS.

OBJECTIVE: To evaluate the predictive factors associated with local recurrence after LITT.

METHODS: Retrospective study with consecutive patients with brain metastases treated with LITT. Based on radiological aspects, lesions were divided into progressive disease after SRS (recurrence or radiation necrosis) and new lesions. Primary endpoint was time to local recurrence.

RESULTS: A total of 61 consecutive patients with 82 lesions (5 newly diagnosed, 46 recurrence, and 31 radiation necrosis). Freedom from local recurrence at 6 mo was 69.6%, 59.4% at 12, and 54.7% at 18 and 24 mo. Incompletely ablated lesions had a shorter median time for local recurrence (P < .001). Larger lesions (>6 cc) had shorter time for local recurrence (P = .03). Dural-based lesions showed a shorter time to local recurrence (P = .01). Tumor recurrence/newly diagnosed had shorter time to local recurrence when compared to RN lesions (P = .01). Patients receiving systemic therapy after LITT had longer time to local recurrence (P = .01). In multivariate Cox-regression model, the HR for incomplete ablated lesions was 4.88 (P < .001), 3.12 (P = .03) for recurrent tumors, and 2.56 (P = .02) for patients not receiving systemic therapy after LITT. Complication rate was 26.2%.

CONCLUSION: Incompletely ablated and recurrent tumoral lesions were associated with higher risk of treatment failure and were the major predicting factors for local recurrence. Systemic therapy after LITT was a protective factor regarding local recurrence.

 

Staged Laser Interstitial Thermal Therapy (LITT) Treatments to Left Insular Low-Grade Glioma

Neurosurgery 2019 DOI:10.1093/neuros/nyz120

Low-grade insular gliomas remain challenging tumors for aggressive resection because of the numerous functional and vascular structures surrounding them. Because of the potential morbidities associated with open surgical resection, less invasive techniques may confer a more optimal balance between cytoreduction and surgical complications. For this reason, we evaluated the use of laser interstitial thermal therapy (LITT) for resection of a dominant hemisphere oligodendroglioma World Health Organization (WHO) grade II in a 68-yr-old patient by use of multiple staged surgeries for its resection.

CLINICAL PRESENTATION: Patient KK was a 68-yr-old female who was found to have a large, left-sided insular mass that was shown to be an oligodendroglioma WHO grade II, positive for codeletion 1p/19q and IDH1 mutant on biopsy. Over the course of 3 mo, KK underwent 2 stages of LITT, targeting different areas of the 5-cmtumor. The 60-d magnetic resonance imaging (MRI) demonstrated a reduction in size of the tumor from5.2×3.3×2.4 cm to 3.6 × 1.9 × 1.4 cm. She returned for a second stage targeting the anterior portion of the tumor. KK did well postoperatively and went on to postsurgical chemoradiation. At the
2-yr follow-up, the lesion showed near resolution on MRI.

CONCLUSION: This case report demonstrates successful use of LITT for staged surgeries to treat a left hemisphere-dominant insular lesion. This establishes the use of LITT as a viable, minimally invasive option to treat tumors that are difficult to access or pose concerns for increased morbidity through an open surgery.

Upfront Magnetic Resonance Imaging-Guided Stereotactic Laser-Ablation in Newly Diagnosed Glioblastoma: A Multicenter Review of Survival Outcomes Compared to a Matched Cohort of Biopsy-Only Patients

Neurosurgery. 2019 Dec 1;85(6):762-772

Laser ablation (LA) is used as an upfront treatment in patients with deep seated newly diagnosed Glioblastoma (nGBM).

OBJECTIVE: To evaluate the outcomes of LA in patients with nGBM and compare them with a matched biopsy-only cohort.

METHODS: Twenty-four nGBM patients underwent upfront LA at Cleveland clinic, Washington University in St. Louis, and Yale University (6/2011-12/2014) followed by chemo/radiotherapy. Also, 24 out of 171 nGBM patients with biopsy followed by chemo/radiotherapy were matched based on age (< 70 vs ≥ 70), gender, tumor location (deep vs lobar), and volume (<11 cc vs ≥11 cc). Progression-free survival (PFS), overall survival (OS), and disease-specific PFS and OS were outcome measures. Three prognostic groups were identified based on extent of tumor ablation by thermal-damage-threshold (TDT)-lines.

RESULTS: The median tumor volume in LA (n = 24) and biopsy only (n = 24) groups was 9.3 cm3 and 8.2 cm3 respectively. Overall, median estimate of OS and PFS in LA cohort was 14.4 and 4.3 mo compared to 15.8 mo and 5.9 mo for biopsy only cohort. On multivariate analysis, favorable TDT-line prognostic groups were associated with lower incidence of disease specific death (P = .03) and progression (P = .05) compared to other groups including biopsy only cohort. Only age (<70 yr, P=.02) and tumor volume (<11 cc, P=.03) were favorable prognostic factors for OS.

CONCLUSION: Themaximum tumor coverage by LA followed by radiation/chemotherapy is an effective treatment modality in patientswith nGBM, compared to biopsy only cohort. The TDT-line prognostic groups were independent predictor of disease specific death and progression after LA.

Laser Interstitial Thermal Therapy for Mesial Temporal Lobe Epilepsy

Neurosurgery 79:S83–S91, 2016

Approximately one-third of patients with epilepsy do not achieve adequate seizure control through medical management alone. Mesial temporal lobe epilepsy (MTLE) is one of the most common forms of medically refractory epilepsy referred for surgical management. Stereotactic laser amygdalohippocampotomy using magnetic resonance–guided laser interstitial thermal therapy (MRg-LITT) is an important emerging therapy for MTLE.

Initial published reports support MRg-LITT as a less invasive surgical option with a shorter hospital stay and fewer neurocognitive side effects compared with craniotomy for anterior temporal lobectomy with amygdalohippocampectomy and selective amygdalohippocampectomy.

We provide a historical overview of laser interstitial thermal therapy development and the technological advancements that led to the currently available commercial systems. Current applications of MRg-LITT for MTLE, reported outcomes, and technical issues of the surgical procedure are reviewed. Although initial reports indicate that stereotactic laser amygdalohippocampotomy may be a safe and effective therapy for medically refractory MTLE, further research is required to establish its long-term effectiveness and its cost/benefit profile.

Laser interstitial thermal therapy followed by minimal-access transsulcal resection for the treatment of large and dif cult to access brain tumors

litt

Neurosurg Focus 41 (4):E14, 2016

Laser interstitial thermal therapy (LITT), sometimes referred to as “stereotactic laser ablation,” has demonstrated utility in a subset of high-risk surgical patients with dificult to access (DTA) intracranial neoplasms. However, the treatment of tumors larger than 10 cm3 is associated with suboptimal outcomes and morbidity. This may limit the utility of LITT in dealing with precisely those large or deep tumors that are most dif cult to treat with conventional approaches. Recently, several groups have reported on minimally invasive transsulcal approaches utilizing tubular retracting systems. However, these approaches have been primarily used for intraventricular or paraventricular lesions, and subtotal resections have been reported for intraparenchymal lesions. Here, the authors describe a combined approach of LITT followed by minimally invasive transsulcal resection for large and DTA tumors.

Methoss The authors retrospectively reviewed the results of LITT immediately followed by minimally invasive, trans-sulcal, transportal resection in 10 consecutive patients with unilateral, DTA malignant tumors > 10 cm3. The patients, 5 males and 5 females, had a median age of 65 years. Eight patients had glioblastoma multiforme (GBM), 1 had a previously treated GBM with radiation necrosis, and 1 had a melanoma brain metastasis. The median tumor volume treated was 38.0 cm3.

Results The median tumor volume treated to the yellow thermal dose threshold (TDT) line was 83% (range 76%– 92%), the median tumor volume treated to the blue TDT line was 73% (range 60%–87%), and the median extent of resection was 93% (range 84%–100%). Two patients suffered mild postoperative neurological de cits, one transiently. Four patients have died since this analysis and 6 remain alive. Median progression-free survival was 280 days, and median overall survival was 482 days.

Conclusions Laser interstitial thermal therapy followed by minimally invasive transsulcal resection, reported here for the first time, is a novel option for patients with large, DTA, malignant brain neoplasms. There were no unexpected neurological complications in this series, and operative characteristics improved as surgeon experience increased. Further studies are needed to elucidate any differences in survival or quality of life metrics.