[Selection of Appropriate Approaches to Preserve Brain Function for Deep Seated Brain Tumors:Our Experience of Two Posterior Thalamic Cases].

What is the most important factor to achieve successful surgery for deep-seated brain tumors with preservation of brain functions? Definitely, it is to identify the tumor origin site at which a tumor arose and select appropriate surgical approaches that immediately lead directly to the site in the early stage of surgery, minimizing damages of cortices and important white matter bundles, and controlling main arterial supply to the tumor. For this, neurosurgeons must have thorough knowledge of brain anatomy and function, and tailor the best surgical approach for each patient, based on three-dimensional anatomical simulation. For lesions situated in the posterior and lower part of the thalamus and extending to the lateral part, two "cross-court" approaches; the occipital transtentorial/falcine and infratentorial supracerebellar transtentorial approaches, provide a wide corridor to even the lateral aspect of the thalamus and early access to the posterior choroidal arteries, usually main feeders of this territory tumors, without damaging any cerebral cortices and major white matter bundles. Here, we describe the selection of approaches for two representative cases and demonstrate surgical procedures and postoperative courses.

Meta-analysis of the impact of laser interstitial hyperthermia on wound healing complications in brain tumors.

High-grade gliomas (HGGs) may be amenable to the neurosurgical technique known as laser interstitial thermal therapy (LITT), which delivers thermal energy to interstitial brain injuries and wounds with pinpoint accuracy. The purpose of this extensive meta-analysis was to evaluate the effects of LITT on wound complications among patients who have brain tumours. Diverse conclusions emerge from a systematic review of pertinent studies, necessitating a comprehensive examination. The meta-analysis, performed utilizing the meta library provided by the R package meta, reveals an initial significant overall effect (RR: -2.1262, 95% CI [-2.7466, -1.5059], p < 0.0001) accompanied by considerable heterogeneity among studies (I2 = 61.13%). Following analyses that specifically examined the incidence of wounds, a complex correlation was found (RR: 0.0471, 95% CI [0.0264, 0.0842], p < 0.0001), indicating that LITT has a discernible but insignificant effect on the occurrence of wounds. Although the meta-analysis emphasizes a notable decrease in wound complications subsequent to LITT treatment, additional research is warranted due to constraints in standardized reporting, data accessibility, and small sample sizes. The results of this study underscore the need for exhaustive protocols to analyse wound complications in patients with brain tumours undergoing LITT.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma and Radiation Necrosis: A Single-Surgeon Case Series.

OBJECTIVE: To evaluate long-term clinical outcomes among patients treated with laser interstitial thermal therapy (LITT) for predicted recurrent glioblastoma (rGBM). METHODS: Patients with rGBM treated by LITT by a single surgeon (2013-2020) were evaluated for progression-free survival (PFS), overall survival (OS), and OS after LITT. RESULTS: Forty-nine patients (33 men, 16 women; mean [SD] age at diagnosis, 58.7 [12.5] years) were evaluated. Among patients with genetic data, 6 of 34 (18%) had IDH-1 R132 mutations, and 7 of 21 (33%) had MGMT methylation. Patients underwent LITT at a mean (SD) of 23.8 (23.8) months after original diagnosis. Twenty of 49 (40%) had previously undergone stereotactic radiosurgery, 37 (75%) had undergone intensity-modulated radiation therapy, and 49 (100%) had undergone chemotherapy. Patients had undergone a mean of 1.2 (0.7) previous resections before LITT. Mean preoperative enhancing and T2 FLAIR volumes were 13.1 (12.8) cm3 and 35.0 (32.8) cm3, respectively. Intraoperative biopsies confirmed rGBM in 31 patients (63%) and radiation necrosis in 18 patients (37%). Six perioperative complications occurred: 3 (6%) cases of worsening aphasia, 1 (2%) seizure, 1 (2%) epidural hematoma, and 1 (2%) intraparenchymal hemorrhage. For the rGBM group, median PFS was 2.0 (IQR, 4.0) months, median OS was 20.0 (IQR, 29.5) months, and median OS after LITT was 6.0 (IQR, 10.5) months. For the radiation necrosis group, median PFS was 4.0 (IQR, 4.5) months, median OS was 37.0 (IQR, 58.0) months, and median OS after LITT was 8.0 (IQR, 23.5) months. CONCLUSIONS: In a diverse rGBM cohort, LITT was associated with a short duration of posttreatment PFS.

Integrating direct electrical brain stimulation with the human connectome.

Neurological and neurodevelopmental conditions are a major public health concern for which new therapies are urgently needed. The development of effective therapies relies on the precise mapping of the neural substrates causally involved in behaviour generation. Direct electrical stimulation (DES) performed during cognitive and neurological monitoring in awake surgery is currently considered the gold standard for the causal mapping of brain functions. However, DES is limited by the focal nature of the stimulation sites, hampering a real holistic exploration of human brain functions at the network level. We used 4137 DES points derived from 612 glioma patients in combination with human connectome data-resting-state functional MRI, n = 1000 and diffusion weighted imaging, n = 284-to provide a multimodal description of the causal macroscale functional networks subtending 12 distinct behavioural domains. To probe the validity of our procedure, we (i) compared the network topographies of healthy and clinical populations; (ii) tested the predictive capacity of DES-derived networks; (iii) quantified the coupling between structural and functional connectivity; and (iv) built a multivariate model able to quantify single subject deviations from a normative population. Lastly, we probed the translational potential of DES-derived functional networks by testing their specificity and sensitivity in identifying critical neuromodulation targets and neural substrates associated with postoperative language deficits. The combination of DES and human connectome data resulted in an average 29.4-fold increase in whole brain coverage compared to DES alone. DES-derived functional networks are predictive of future stimulation points (97.8% accuracy) and strongly supported by the anatomical connectivity of subcortical stimulations. We did not observe any significant topographical differences between the patients and the healthy population at both group and single subject level. Showcasing concrete clinical applications, we found that DES-derived functional networks overlap with effective neuromodulation targets across several functional domains, show a high degree of specificity when tested with the intracranial stimulation points of a different stimulation technique and can be used effectively to characterize postoperative behavioural deficits. The integration of DES with the human connectome fundamentally advances the quality of the functional mapping provided by DES or functional imaging alone. DES-derived functional networks can reliably predict future stimulation points, have a strong correspondence with the underlying white matter and can be used for patient specific functional mapping. Possible applications range from psychiatry and neurology to neuropsychology, neurosurgery and neurorehabilitation.

Primary Gamma Knife Radiosurgery for pineal region tumors: A systematic review and pooled analysis of available literature with histological stratification.

Pineal region tumors (PTs) represent extremely rare pathologies, characterized by highly heterogeneous histological patterns. Most of the available evidence for Gamma Knife radiosurgical (GKSR) treatment of PTs arises from multimodal regimens, including GKSR as an adjuvant modality or as a salvage treatment at recurrence. We aimed to gather existing evidence on the topic and analyze single-patient-level data to address the efficacy and safety of primary GKSR. This is a systematic review of the literature (PubMed, Embase, Cochrane, Science Direct) and pooled analysis of single-patient-level data. A total of 1054 original works were retrieved. After excluding duplicates and irrelevant works, we included 13 papers (n = 64 patients). An additional 12 patients were included from the authors' original series. A total of 76 patients reached the final analysis; 56.5% (n = 43) received a histological diagnosis. Confirmed lesions included pineocytoma WHO grade I (60.5%), pineocytoma WHO grade II (14%), pineoblastoma WHO IV (7%), pineal tumor with intermediate differentiation WHO II/III (4.7%), papillary tumor of pineal region WHO II/III (4.7%), germ cell tumor (2.3%), neurocytoma WHO I (2.3%), astrocytoma WHO II (2.3%) and WHO III (2.3%). Presumptive diagnoses were achieved in the remaining 43.5% (n = 33) of cases and comprised of pineocytoma (9%), germ cell tumor (6%), low-grade glioma (6%), high-grade glioma (3%), meningioma (3%) and undefined in 73%. The mean age at the time of GKSR was 38.7 years and the mean lesional volume was 4.2 ± 4 cc. All patients received GKSR with a mean marginal dose of 14.7 ± 2.1 Gy (50% isodose). At a median 36-month follow-up, local control was achieved in 80.3% of cases. Thirteen patients showed progression after a median time of 14 months. Overall mortality was 13.2%. The median OS was not reached for all included lesions, except high-grade gliomas (8mo). The 3-year OS was 100% for LGG and pineal tumors with intermediate differentiation, 91% for low-grade pineal lesions, 66% for high-grade pineal lesions, 60% for germ cell tumors (GCTs), 50% for HGG, and 82% for undetermined tumors. The 3-year progression-free survival (PFS) was 100% for LGG and pineal intermediate tumors, 86% for low-grade pineal, 66% for high-grade pineal, 33.3% for GCTs, and 0% for HGG. Median PFS was 5 months for HGG and 34 months for GCTs. The radionecrosis rate was 6%, and cystic degeneration was observed in 2%. Ataxia as a presenting symptom strongly predicted mortality (odds ratio [OR] 104, p = .02), while GCTs and HGG histology well predicted PD (OR: 13, p = .04). These results support the efficacy and safety of primary GKSR treatment of PTs. Further studies are needed to validate these results, which highlight the importance of the initial presumptive diagnosis for choosing the best therapeutic strategy.

Asleep-awake-asleep versus hypnosis for low-grade glioma surgery: long term follow-up outcome.

BACKGROUND: Hypnosis-aided craniotomy is a safe alternative to standard asleep-awake-asleep (AAA) surgery in glioma surgery. The impact of these two anesthetic methods on tumor prognosis has never been assessed. OBJECTIVE: This study aimed to evaluate the possible impact of the type of sedation (i.e., hypnosedation vs. standard sedation) on postoperative outcomes in awake surgery for gliomas. METHODS: Adult patients who underwent awake surgery for a diffuse glioma, excluding glioblastomas, between May 2011 and December 2019 at the authors' institution were included in the analysis. Pearson Chi-square, Fisher exact, and Mann-Whitney U tests were used for inferential analyses. RESULTS: Sixty-one (61) patients were included, thirty-one were female (50.8 %), and the mean age was 41.8 years (SD = 11.88). Most patients had IDH mutated tumors (n = 51; 83.6%). Twenty-six patients (42.6%) were hypnosedated while 35 (57.4%) received standard AAA procedure. The overall median follow-up time was 48 months (range: 10 months-120 months). Our results did not identify any significant difference between both techniques in terms of extent of resection (sub-total resection >95% rates were 11.48% vs. 8.20%, OR = 2.2, 95% CI = 0.62-8.44; P = 0.34) and of overall survival (87.5% of patients in the AAA surgery group reach 9 years OS vs. 79% in the hypnosis cohort, cHR = 0.85, 95% CI = 0.12-6.04; P = 0.87). CONCLUSION: Hypnosis for awake craniotomy is rarely proposed although it is a suitable alternative to standard sedation in awake craniotomy for LGGs, with similar results in terms of extent of resection or survival.

Application Value of Magnetic Resonance Imaging Medical Technology in the Perioperative Management of Brain Gliomas: Impact on Anesthesia and Prognosis.

Objective: To assess the utility of magnetic resonance imaging (MRI) medical technology in the perioperative management of brain gliomas and its impact on anesthesia and prognosis. Methods: An observational, retrospective comparative study was conducted. We selected 60 patients who underwent glioma resection at our hospital from January 2019 to January 2020. Patients were divided into two groups based on admission order: the experimental group (EG) and the control group (CG), with 30 cases each. Patients in the CG underwent conventional intracranial tumor surgery, while those in the EG underwent supratentorial craniotomy for tumor resection with the assistance of MRI medical technology. We compared perioperative parameters, hemodynamic indices, tumor resection outcomes, postoperative complications, and postoperative physical function between the two groups. Results: Compared to the CG, the EG had significantly longer surgery preparation time, anesthesia time, and surgery time (P < .001). However, there were no significant between-group differences in infusion volume and intraoperative blood loss (P > .05). Postoperative hemodynamic indicators were significantly higher in the EG than in the CG (P < .001), and postoperative tumor volume was markedly smaller in the EG (P < .001). The EG also achieved a significantly larger volume of tumor resection and a higher tumor resection rate (P < .001), a significantly lower total incidence of postoperative complications (P < .05), and notably higher Karnofsky Performance Status (KPS) scores (P < .001). Conclusions: Compared to conventional intracranial tumor surgery, the utilization of MRI medical technology in brain glioma surgery, although it prolongs surgery and anesthesia times, enhances the tumor resection rate, and offers significant advantages in improving the prognosis of patients with brain glioma.

Towards the definition of progressive disease in brain metastasis treated with laser ablation: an evidence-based study.

PURPOSE: The postoperative period after laser interstitial thermal therapy (LITT) is marked by a temporary increase in volume, which can impact the accuracy of radiographic assessment. The current criteria for progressive disease (PD) suggest that a 20% increase in size of brain metastasis (BM) assessed in 6-12 weeks intervals should be considered as local progression (LP). However, there is no agreement on how LP should be defined in this context. In this study, we aimed to statistically analyze which tumor volume variations were associated with LP. METHODS: We analyzed 40 BM that underwent LITT between 2013 and 2022. For this study, LP was defined following radiographic features. A ROC curve was generated to evaluate volume change as a predictor of LP and find the optimal cutoff point. A logistic regression analysis and Kaplan Meier curves were performed to assess the impact of various clinical variables on LP. RESULTS: Out of 40 lesions, 12 (30%) had LP. An increase in volume of 25.6% from baseline within 120-180 days after LITT presented a 70% sensitivity and 88.9% specificity for predicting LP (AUC: 0.78, p = 0.041). The multivariate analysis showed a 25% increase in volume between 120 and 180 days as a negative predictive factor (p = 0.02). Volumetric changes within 60-90 days after LITT did not predict LP (AUC: 0.57; p = 0.61). CONCLUSION: Volume changes within the first 120 days after the procedure are not independent indicators of LP of metastatic brain lesions treated with LITT.

Gold Nanostars Obviate Limitations to Laser Interstitial Thermal Therapy (LITT) for the Treatment of Intracranial Tumors.

PURPOSE: Laser interstitial thermal therapy (LITT) is an effective minimally invasive treatment option for intracranial tumors. Our group produced plasmonics-active gold nanostars (GNS) designed to preferentially accumulate within intracranial tumors and amplify the ablative capacity of LITT. EXPERIMENTAL DESIGN: The impact of GNS on LITT coverage capacity was tested in ex vivo models using clinical LITT equipment and agarose gel-based phantoms of control and GNS-infused central "tumors." In vivo accumulation of GNS and amplification of ablation were tested in murine intracranial and extracranial tumor models followed by intravenous GNS injection, PET/CT, two-photon photoluminescence, inductively coupled plasma mass spectrometry (ICP-MS), histopathology, and laser ablation. RESULTS: Monte Carlo simulations demonstrated the potential of GNS to accelerate and specify thermal distributions. In ex vivo cuboid tumor phantoms, the GNS-infused phantom heated 5.5× faster than the control. In a split-cylinder tumor phantom, the GNS-infused border heated 2× faster and the surrounding area was exposed to 30% lower temperatures, with margin conformation observed in a model of irregular GNS distribution. In vivo, GNS preferentially accumulated within intracranial tumors on PET/CT, two-photon photoluminescence, and ICP-MS at 24 and 72 hours and significantly expedited and increased the maximal temperature achieved in laser ablation compared with control. CONCLUSIONS: Our results provide evidence for use of GNS to improve the efficiency and potentially safety of LITT. The in vivo data support selective accumulation within intracranial tumors and amplification of laser ablation, and the GNS-infused phantom experiments demonstrate increased rates of heating, heat contouring to tumor borders, and decreased heating of surrounding regions representing normal structures.

Free-water correction DTI-based tractography in brain tumor surgery: assessment with functional and electrophysiological mapping of the white matter.

Peritumoral edema prevents fiber tracking from diffusion tensor imaging (DTI). A free-water correction may overcome this drawback, as illustrated in the case of a patient undergoing awake surgery for brain metastasis. The anatomical plausibility and accuracy of tractography with and without free-water correction were assessed with functional mapping and axono-cortical evoked-potentials (ACEPs) as reference methods. The results suggest a potential synergy between corrected DTI-based tractography and ACEPs to reliably identify and preserve white matter tracts during brain tumor surgery.

Development of an educational method to rethink and learn oncological brain surgery in an "a la carte" connectome-based perspective.

BACKGROUND: Understanding the structural connectivity of white matter tracts (WMT) and their related functions is a prerequisite to implementing an "a la carte" "connectomic approach" to glioma surgery. However, accessible resources facilitating such an approach are lacking. Here we present an educational method that is readily accessible, simple, and reproducible that enables the visualization of WMTs on individual patient images via an atlas-based approach. METHODS: Our method uses the patient's own magnetic resonance imaging (MRI) images and consists of three main steps: data conversion, normalization, and visualization; these are accomplished using accessible software packages and WMT atlases. We implement our method on three common cases encountered in glioma surgery: a right supplementary motor area tumor, a left insular tumor, and a left temporal tumor. RESULTS: Using patient-specific perioperative MRIs with open-sourced and co-registered atlas-derived WMTs, we highlight the critical subnetworks requiring specific surgical monitoring identified intraoperatively using direct electrostimulation mapping with cognitive monitoring. The aim of this didactic method is to provide the neurosurgical oncology community with an accessible and ready-to-use educational tool, enabling neurosurgeons to improve their knowledge of WMTs and to better learn their oncologic cases, especially in glioma surgery using awake mapping. CONCLUSIONS: Taking no more than 3-5 min per patient and irrespective of their resource settings, we believe that this method will enable junior surgeons to develop an intuition, and a robust 3-dimensional imagery of WMT by regularly applying it to their cases both before and after surgery to develop an "a la carte" connectome-based perspective to glioma surgery.

Nuancing the Limitations of Axonal Plasticity in World Health Organization Grade II Gliomas: White Matter Tracts Compensation Is Driven by Cortical Remodeling.

Diffuse World Health Organization grade II glioma (GIIG) is a slow-growing brain cancer that migrates along the white matter (WM) tracts. Neuroplastic changes were described in reaction to GIIG progression, opening the window to extensive cerebral surgical resection in patients able to resume an active life with no functional consequences. However, atlases of cortico-subcortical neural plasticity emphasized the limited potential of axonal reorganization. Yet, the removal of WM involved by GIIG can be possible, at least to some extent, without generating permanent neurological disturbances. Here, the aim was to discuss mechanisms underlying functional compensation which make feasible resection of the subcortical component of GIIG and to propose a new model of adaptative neural reconfiguration at the level of the axonal connectivity. In this model, 2 parts of the WM tracts are considered: (1) the stem of the bundle that represents the actual limitation of plastic potential, as supported by reproducible behavioral disorders elicited by intraoperative axonal electrostimulation mapping (ESM) and (2) the terminations/origins of the bundle that may no longer be critical in case of functional reallocation of the cortex to/from which these WM fibers run-thus inducing no behavioral troubles during direct ESM. Understanding that a certain degree of axonal compensation in specific portions of the tracts is driven by cortical remodeling may enable to rethink the concept of WM plasticity and to refine the preoperative estimation of extent of resection for GIIG. Identifying eloquent fibers by ESM, especially their convergence in the depth, is essential to achieve an individualized connectome-based resection.

Laser Interstitial Thermal Therapy for Radionecrosis.

Radiotherapy is widely used for brain tumors but can cause radiation necrosis (RN). Laser interstitial thermal therapy (LITT) is a relatively new therapeutic modality for RN and its impact on patient outcome is still not well understood. Based on a systematic literature search (n=33), the authors discuss the available evidence. Most studies found a positive safety/efficacy profile, as LITT may help to lengthen survival, prevent progression, taper steroids, and improve neurological symptoms while remaining safe. Prospective studies on this subject are needed and may result in LITT becoming an essential therapeutic option for the treatment of RN.

A single-center prospective study regarding time to return to activities of daily living after craniotomy for brain tumors.

BACKGROUND: There are few studies on the time to return to activities of daily living (ADL) after craniotomy in patients with brain tumors. This study aimed to investigate the duration before returning to ADLs after craniotomy for brain tumors and present data that can provide information and guidelines on the appropriate time needed. METHODS: Patients (n = 183 of 234) who underwent craniotomy for brain tumors between April 2021 and July 2021 capable of self-care upon discharge were enrolled, and data of 158 were collected. The start time of 85 ADL items was prospectively investigated for 4 months postoperatively, using the self-recording sheet. RESULTS: Over 89% and 87% of the patients performed basic ADL items within a month and instrumental ADL items within 2 months (medians: within 18 days), except for a few. Regarding work, 50% of the patients returned within 4 months. Washing hair with a wound was performed at 18 days of median value, after 4 months of dyeing/perming hair, 6 days of drinking coffee/tea, after 4 months of air travel, and 40 days of complementary and alternative medicine. In patients with infratentorial tumors or surgical problems, return times were much later for various items. CONCLUSIONS: It is possible to provide practical information and guidelines on the duration to return to ADL after craniotomy in brain tumor patients. These study findings also reduce uncertainty about recovery and daily life and help patients return to their daily life at the appropriate time, thereby maintaining function and daily well-being after surgery.

Surgical Approaches to Thalamic Gliomas: A Systematic Review.

BACKGROUND: Adult thalamic gliomas (ATGs) present a surgical challenge given their depth and proximity to eloquent brain regions. Choosing a surgical approach relies on different clinical variables such as anatomical location and size of the tumor. However, conclusive data regarding how these variables influence the balance between extent of resection and complications are lacking. We aim to systematically review the literature to describe the current surgical outcomes of ATG and to provide tools that may improve the decision-making process. METHODS: Literature regarding the surgical management of ATG patients was reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Four databases were queried and a description of clinical characteristics and survival analysis were performed. An individual patient data analysis was conducted when feasible. RESULTS: A total of 462 patients were included from 13 studies. The mean age was 39.8 years with a median preoperative Karnofsky performance scale of 70. The lateral approaches were most frequently used (74.9%), followed by the interhemispheric (24.2%). Gross total and subtotal/partial resections were achieved in 81%, and 19% of all cases, respectively. New permanent neurological deficits were observed in 51/433 patients (11.8%). individual patient data was pooled from 5 studies (n = 71). In the multivariate analysis, tumors located within the posterior thalamus had worse median overall survival compared to anterior gliomas (14.5 vs. 27 months, P = 0.003). CONCLUSIONS: Surgical resection of ATGs can increase survival but at the risk of operative morbidity. Knowing which factors impact survival may allow neurosurgeons to propose a more evidence-based treatment to their patients.

Laser Interstitial Thermal Therapy for the Treatment of Primary and Metastatic Brain Tumors: A Systematic Review and Meta-Analysis.

BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for intracranial tumors that are challenging to treat via traditional methods; however, its safety and efficacy are not yet well validated in the literature. The objectives of the study were to assess the available evidence of the indications and adverse events (AEs) of LITT and 1-year progression-free survival and 1-year overall survival in the treatment of primary and secondary brain tumors. METHODS: A comprehensive literature search was conducted through the databases PubMed, Embase, and the Cochrane Library until October 2021. Comparative and descriptive studies, except for case reports, were included in the meta-analysis. Separate analyses by tumor type (high-grade gliomas, including World Health Organization grade 4 astrocytomas [which include glioblastomas] as a specific subgroup; low-grade gliomas; and brain metastases) were conducted. Pooled effect sizes and their 95% confidence intervals (CI) were generated via random-effects models. RESULTS: Forty-five studies met the inclusion criteria, yielding 826 patients for meta-analysis. There were 829 lesions in total, of which 361 were classified as high-grade gliomas, 116 as low-grade gliomas, 337 as metastatic brain tumors, and 15 as nonglial tumors. Indications for offering LITT included deep/inaccessible tumor (12 studies), salvage therapy after failed radiosurgery (9), failures of ≥2 treatment options (3), in pediatric patients (4), patient preference (1); indications were nonspecific in 12 studies. Pooled incidence of all (minor or major) procedure-related AEs was 30% (95% CI, 27%-40%) for all tumors. Pooled incidence of neurologic deficits (minor or major) was 16% (12%-22%); postprocedural edema 14% (8%-22%); seizure 6% (4%-9%); hematoma 20% (14%-29%); deep vein thrombosis 19% (11%-30%); hydrocephalus 8% (5%-12%); and wound infection 5% (3%-7%). One-year progression-free survival was 18.6% (11.3%-29.0%) in high-grade gliomas, 16.9% (11.6%-24.0%) among the grade 4 astrocytomas; and 51.2% (36.7%-65.5%) in brain metastases. One-year overall survival was 43.0% (36.0%-50.0%) in high-grade glioma, 45.9% (95% CI, 37.9%-54%) in grade 4 astrocytomas; 93.0% (42.3%-100%) in low-grade gliomas, and 56.3% (47.0%-65.3%) in brain metastases. CONCLUSIONS: New neurologic deficits and postprocedural edema were the most reported AEs after LITT, albeit mostly transient. This meta-analysis provides the best statistical estimates of progression and survival outcomes based on the available information. LITT is generally a safe procedure for selected patients, and future well-designed comparative studies on its outcomes versus the current standard of care should be performed.

Laser hyperthermia: Past, present, and future.

Magnetic resonance imaging-guided laser interstitial thermal therapy (LITT) is an ablative procedure using heat from a laser to provide cytoreduction in tissue. It is a minimally invasive procedure that has been used in intracranial pathologies such as high-grade gliomas, metastatic lesions, epilepsy, and other lesions. While LITT may offer a more acceptable complication profile compared to open surgery, the role of laser therapy for intracranial lesions in current treatment paradigms continues to evolve. This review will focus on the background and application of LITT, the current evidence for its use, and future directions for the technology.