Probabilistic Presurgical Language Functional MRI Atlas of Brain Tumor Patients.

BACKGROUND AND PURPOSE: Patients with brain tumors have high intersubject variation in putative language regions, which may limit the utility of straightforward application of healthy-subject brain atlases in clinical scenarios. The purpose of this study was to develop a probabilistic functional brain atlas that consolidates language functional activations of sentence completion and silent word generation language paradigms using a large sample of patients with brain tumors. MATERIALS AND METHODS: The atlas was developed using retrospectively collected fMRI data from patients with brain tumors who underwent their first standard-of-care presurgical language fMRI scan at our institution between July 18, 2015, and May 13, 2022. 317 patients (861 fMRI scans) were used to develop the language functional atlas. An independent presurgical language fMRI dataset of 39 patients with brain tumors from a previous study was used to evaluate our atlas. Family-wise error corrected binary functional activation maps from sentence completion, letter fluency, and category fluency presurgical fMRI were used to create probability overlap maps and pooled probabilistic overlap map in Montreal Neurological Institute standard space. Wilcoxon signed-rank test was used to determine significant difference in the maximum Dice coefficient for our atlas compared to a meta-analysis-based template with respect to expert-delineated primary language area activations. RESULTS: Probabilities of activating left anterior primary language area and left posterior primary language area in temporal lobe were 87.9% and 91.5%, respectively, for sentence completion, 88.5% and 74.2%, respectively, for letter fluency, and 83.6% and 67.6%, respectively, for category fluency. Maximum Dice coefficients for templates derived from our language atlas were significantly higher than the meta-analysis-based template in left anterior primary language area (0.351 and 0.326, respectively, P < .05) and left posterior primary language area in temporal lobe (0.274 and 0.244, respectively, P < .005). CONCLUSIONS: Brain tumor patient-and paradigm-specific probabilistic language atlases were developed. These atlases had superior spatial agreement with fMRI activations in individual patients than the meta-analysis-based template. ABBREVIATIONS: SENT = sentence completion, LETT = letter fluency, CAT = category fluency, PLA = primary language area, aPLA = anterior PLA, pPLAT = posterior PLA in the temporal lobe, pPLAP = posterior PLA in the parietal lobe, SMA = supplementary motor area, DLPFC = dorsolateral prefrontal cortex, BTLA = basal temporal language area.

Comparative analysis of brain language templates with primary language areas detected from presurgical fMRI of brain tumor patients.

INTRODUCTION: Functional brain templates are often used in the analysis of clinical functional MRI (fMRI) studies. However, these templates are mostly built based on anatomy or fMRI of healthy subjects, which have not been fully vetted in clinical cohorts. Our aim was to evaluate language templates by comparing with primary language areas (PLAs) detected from presurgical fMRI of brain tumor patients. METHODS: Four language templates (A-D) based on anatomy, task-based fMRI, resting-state fMRI, and meta-analysis, respectively, were compared with PLAs detected by fMRI with word generation and sentence completion paradigms. For each template, the fraction of PLA activations enclosed by the template (positive inclusion fraction, [PIF]), the fraction of activations within the template but that did not belong to PLAs (false inclusion fraction, [FIF]), and their Dice similarity coefficient (DSC) with PLA activations were calculated. RESULTS: For anterior PLAs, Template A had the greatest PIF (median, 0.95), whereas Template D had both the lowest FIF (median, 0.074), and the highest DSC (median, 0.30), which were all significant compared to other templates. For posterior PLAs, Templates B and D had similar PIF (median, 0.91 and 0.90, respectively) and DSC (both medians, 0.059), which were all significantly higher than that of Template C. Templates B and C had significantly lower FIF (median, 0.061 and 0.054, respectively) compared to Template D. CONCLUSION: This study demonstrated significant differences between language templates in their inclusiveness of and spatial agreement with the PLAs detected in the presurgical fMRI of the patient cohort. These findings may help guide the selection of language templates tailored to their applications in clinical fMRI studies.

Additive Value of MR Simulation Prior to Chemoradiation in Evaluating Treatment Response and Pseudoprogression in High-Grade Gliomas.

BACKGROUND: A dedicated MRI Simulation(MRsim) for radiation treatment(RT) planning in high-grade glioma(HGG) patients can detect early radiological changes, including tumor progression after surgery and before standard of care chemoradiation. This study aimed to determine the impact of using post-op MRI vs. MRsim as the baseline for response assessment and reporting pseudo-progression on follow-up imaging at one month(FU1) after chemoradiation. METHODS: Histologically confirmed HGG patients were planned for six weeks of RT in a prospective study for adaptive RT planning. All patients underwent post-op MRI, MRsim, and follow-up MRI scans every 2-3 months. Tumor response was assessed by three independent blinded reviewers using Response Assessment in Neuro-Oncology(RANO) criteria when baseline was either post-op MRI or MRsim. Interobserver agreement was calculated using light's kappa. RESULTS: 30 patients (median age 60.5 years; IQR 54.5-66.3) were included. Median interval between surgery and RT was 34 days (IQR 27-41). Response assessment at FU1 differed in 17 patients (57%) when the baseline was post-op MRI vs. MRsim, including true progression vs. partial response(PR) or stable disease(SD) in 11 (37%) and SD vs. PR in 6 (20%) patients. True progression was reported in 19 patients (63.3%) on FU1 when the baseline was post-op MRI vs 8 patients (26.7%) when the baseline was MRsim (p=.004). Pseudo-progression was observed at FU1 in 12 (40%) vs. 4 (13%) patients, when the baseline was post-op MRI vs. MRsim (p=.019). Interobserver agreement between observers was moderate (κ = 0.579; p<0.001). CONCLUSIONS: Our study demonstrates the value of acquiring an updated MR closer to RT in patients with HGG to improve response assessment, and accuracy in evaluation of pseudo-progression even at the early time point of first follow-up after RT. Earlier identification of patients with true progression would enable more timely salvage treatments including potential clinical trial enrolment to improve patient outcomes.

Collision tumor: Multinodular and vacuolating neuronal tumor with isocitrate dehydrogenase-mutant diffuse astrocytoma.

Herein, we report a case of a collision tumor involving a multinodular and vacuolating neuronal tumor (MVNT) and a diffuse astrocytoma. A collision tumor between these two entities has not previously been reported. The patient is a 35-year-old woman who presented with new-onset hearing loss and ringing in her right ear. Magnetic resonance imaging identified a non-enhancing mass involving the gray matter and subcortical white matter of the left middle frontal gyrus. Additionally, tiny clustered nodules were noted along the underlying subcortical ribbon and superficial subcortical white matter of the left superior frontal gyrus. The patient underwent a left frontal craniotomy and complete resection of the mass. Histologic examination of the resected specimen demonstrated a collision tumor consisting of a diffuse astrocytoma (isocitrate dehydrogenase [IDH] mutant, central nervous system [CNS] World Health Organization [WHO] grade 2) and an MVNT, with the latter demonstrating characteristic morphologic and immunohistochemical features.

Intraoperative language mapping guided by real-time visualization of gamma band modulation electrocorticograms: Case report and proof of concept.

Background: Electrocorticography (ECoG) language mapping is often performed extraoperatively, frequently involves offline processing, and relationships with direct cortical stimulation (DCS) remain variable. We sought to determine the feasibility and preliminary utility of an intraoperative language mapping approach guided by real-time visualization of electrocorticograms. Methods: A patient with astrocytoma underwent awake craniotomy with intraoperative language mapping, utilizing a dual iPad stimulus presentation system coupled to a real-time neural signal processing platform capable of both ECoG recording and delivery of DCS. Gamma band modulations in response to 4 language tasks at each electrode were visualized in real-time. Next, DCS was conducted for each neighboring electrode pair during language tasks. Results: All language tasks resulted in strongest heat map activation at an electrode pair in the anterior to mid superior temporal gyrus. Consistent speech arrest during DCS was observed for Object and Action naming tasks at these same electrodes, indicating good correspondence with ECoG heat map recordings. This region corresponded well with posterior language representation via preoperative functional MRI. Conclusions: Intraoperative real-time visualization of language task-based ECoG gamma band modulation is feasible and may help identify targets for DCS. If validated, this may improve the efficiency and accuracy of intraoperative language mapping.

Incidence of resting-state functional connectivity to secondary language areas and contralateral language areas in patients with brain tumors.

PURPOSE: Secondary language areas, including the pre-supplementary motor area (pre-SMA), dorsolateral prefrontal cortex (DLPFC), and the visual word form area (VWFA) play important roles in speech, but have been under-evaluated in the realm of resting-state (rs)-fMRI. The purpose of this study is to determine the incidence that secondary language areas and contralateral language areas can be localized using seed-based correlation (SBC) rs-fMRI. METHODS: We retrospectively reviewed 40 rs-fMRIs for functional connectivity (FC) to secondary language areas in cases where FC to Broca's or Wernicke's area near tumor in the left hemisphere were successfully generated using SBC analysis. Logistical regression was used for statistical analysis. RESULTS: SBC rs-fMRI with a seed in the left Broca's or Wernicke's area ipsilateral to the tumor was performed in the 40 patients. 72.5% of cases showed FC to the left DLPFC, 67.5% to left pre-SMA, and 52.5% of cases had FC to right Broca's area. In addition to other correlations, we found older patients have a lower incidence of FC to the right Wernicke's area when seeded from both left Broca's and left Wernicke's area (p-value = .016, odds ratio = 0.94). CONCLUSION: SBC rs-fMRI can detect left hemispheric secondary language areas as well as right hemispheric primary and secondary language areas. The left DLPFC showed the highest incidence of FC, followed by the left pre-SMA when seeded from both left Broca's and Wernicke's area. Logistics regression also showed in some instances, differences in the incidence of FC to language areas was dependent on age, seed location, and gender.

Multifocal and multicentric glioblastoma: Imaging signature, molecular characterization, patterns of spread, and treatment.

Multifocal and multicentric glioblastoma (GBM) or collectively, m-GBM, is an imaging diagnosis present in up to 34% of patients with GBM. Compared to unifocal disease, patients with m-GBM have worse outcomes owing to the enhanced aggressive nature of the disease and its resistance to currently available treatments. To improve the understanding of its complex behavior, many associations have been established between the radiologic findings of m-GBM and its gross histology, genetic composition, and patterns of spread. Additionally, the holistic knowledge of the exact mechanisms of m-GBM genesis and progression is crucial for identifying potential targets permitting enhanced diagnosis and treatment. In this review, we aim to provide a comprehensive summary of the cumulative knowledge of the unique molecular biology and behavior of m-GBM and the association of these features with neuroimaging.

Comparative study of preoperative functional imaging combined with tractography for prediction of iatrogenic motor deficits.

OBJECTIVE: Robust preoperative imaging can improve the extent of resection in patients with brain tumors while minimizing postoperative neurological morbidity. Both structural and functional imaging techniques can provide helpful preoperative information. A recent study found that transcranial magnetic stimulation (TMS) tractography has significant predictive value for permanent deficits. The present study directly compares the predictive value of TMS tractography and task-based functional MRI (fMRI) tractography in the same cohort of glioma patients. METHODS: Clinical outcome data were collected from charts of patients with motor eloquent glioma and preoperative fMRI and TMS studies. The primary outcome was a new or worsened motor deficit present at the 3-month postoperative follow-up, which was termed a "permanent deficit." Postoperative MR images were overlaid onto preoperative plans to determine which imaging features were resected. Multiple fractional anisotropic thresholds (FATs) were screened for both TMS and fMRI tractography. The predictive value of the various thresholds was modeled using receiver operating characteristic curve analysis. RESULTS: Forty patients were included in this study. Six patients (15%) sustained permanent postoperative motor deficits. A significantly greater predictive value was found for TMS tractography than for fMRI tractography regardless of the FAT. Despite 35% of patients showing clinically relevant neuroplasticity captured by TMS, only 2.5% of patients showed a blood oxygen level-dependent signal displaced from the precentral gyrus. Comparing the best-performing FAT for both modalities, TMS seeded tractography showed superior predictive value across all metrics: sensitivity, specificity, positive predictive value, and negative predictive value. CONCLUSIONS: The results from this study indicate that the prediction of permanent deficits with TMS tractography is superior to that with fMRI tractography, possibly because TMS tractography captures clinically relevant neuroplasticity. However, future large-scale prospective studies are needed to fully illuminate the proper role of each modality in comprehensive presurgical workups for patients with motor-eloquent tumors.

Pre-operative MRI radiomics model non-invasively predicts key genomic markers and survival in glioblastoma patients.

PURPOSE: Although glioblastoma (GBM) is the most common primary brain malignancy, few tools exist to pre-operatively risk-stratify patients by overall survival (OS) or common genetic alterations. We developed an MRI-based radiomics model to identify patients with EGFR amplification, MGMT methylation, GBM subtype, and OS greater than 12 months. METHODS: We retrospectively identified 235 patients with pathologically confirmed GBMs from the Cancer Genome Atlas (88; TCGA) and MD Anderson Cancer Center (147; MDACC). After two neuroradiologists segmented MRI tumor volumes, we extracted first-order and second-order radiomic features (gray-level co-occurrence matrices). We used the Maximum Relevance Minimum Redundancy technique to identify the 100 most relevant features and validated models using leave-one-out-cross-validation and validation on external datasets (i.e., TCGA). Our results were reported as the area under the curve (AUC). RESULTS: The MDACC patient cohort had significantly higher OS (22 months) than the TCGA dataset (14 months). On both LOOCV and external validation, our radiomics models were able to identify EGFR amplification (all AUCs > 0.83), MGMT methylation (all AUCs > 0.85), GBM subtype (all AUCs > 0.92), and OS (AUC > 0.91 on LOOCV and 0.71 for TCGA validation). CONCLUSIONS: Our robust radiomics pipeline has the potential to pre-operatively discriminate common genetic alterations and identify patients with favorable survival.

Transcranial magnetic stimulation (TMS) seeded tractography provides superior prediction of eloquence compared to anatomic seeded tractography.

Background: For patients with brain tumors, maximizing the extent of resection while minimizing postoperative neurological morbidity requires accurate preoperative identification of eloquent structures. Recent studies have provided evidence that anatomy may not always predict eloquence. In this study, we directly compare transcranial magnetic stimulation (TMS) data combined with tractography to traditional anatomic grading criteria for predicting permanent deficits in patients with motor eloquent gliomas. Methods: We selected a cohort of 42 glioma patients with perirolandic tumors who underwent preoperative TMS mapping with subsequent resection and intraoperative mapping. We collected clinical outcome data from their chart with the primary outcome being new or worsened motor deficit present at 3 month follow up, termed "permanent deficit". We overlayed the postoperative resection cavity onto the preoperative MRI containing preoperative imaging features. Results: Almost half of the patients showed TMS positive points significantly displaced from the precentral gyrus, indicating tumor induced neuroplasticity. In multivariate regression, resection of TMS points was significantly predictive of permanent deficits while the resection of the precentral gyrus was not. TMS tractography showed significantly greater predictive value for permanent deficits compared to anatomic tractography, regardless of the fractional anisotropic (FA) threshold. For the best performing FA threshold of each modality, TMS tractography provided both higher positive and negative predictive value for identifying true nonresectable, eloquent cortical and subcortical structures. Conclusion: TMS has emerged as a preoperative mapping modality capable of capturing tumor induced plastic reorganization, challenging traditional presurgical imaging modalities.

Cerebrovascular Reactivity Mapping Using Resting-State Functional MRI in Patients With Gliomas.

BACKGROUND: Recently, a data-driven regression analysis method was developed to utilize the resting-state (rs) blood oxygenation level-dependent signal for cerebrovascular reactivity (CVR) mapping (rs-CVR), which was previously optimized by comparing with the CO2 inhalation-based method in health subjects and patients with neurovascular diseases. PURPOSE: To investigate the agreement of rs-CVR and the CVR mapping with breath-hold MRI (bh-CVR) in patients with gliomas. STUDY TYPE: Retrospective. POPULATION: Twenty-five patients (12 males, 13 females; mean age ± SD, 48 ± 13 years) with gliomas. FIELD STRENGTH/SEQUENCE: Dynamic T2*-weighted gradient-echo echo-planar imaging during a breath-hold paradigm and during the rs on a 3-T scanner. ASSESSMENT: rs-CVR with various frequency ranges and resting-state fluctuation amplitude (RSFA) were assessed. The agreement between each rs-based CVR measurement and bh-CVR was determined by voxel-wise correlation and Dice coefficient in the whole brain, gray matter, and the lesion region of interest (ROI). STATISTICAL TESTS: Voxel-wise Pearson correlation, Dice coefficient, Fisher Z-transformation, repeated-measure analysis of variance and post hoc test with Bonferroni correction, and nonparametric repeated-measure Friedman test and post hoc test with Bonferroni correction were used. Significance was set at P < 0.05. RESULTS: Compared with bh-CVR, the highest correlations were found at the frequency bands of 0.04-0.08 Hz and 0.02-0.04 Hz for rs-CVR in both whole brain and the lesion ROI. RSFA had significantly lower correlations than did rs-CVR of 0.02-0.04 Hz and a wider frequency range (0-0.1164 Hz). Significantly higher correlations and Dice coefficient were found in normal tissues than in the lesion ROI for all three methods. DATA CONCLUSION: The optimal frequency ranges for rs-CVR are determined by comparing with bh-CVR in patients with gliomas. The rs-CVR method outperformed the RSFA. Significantly higher correlation and Dice coefficient between rs- and bh-CVR were found in normal tissue than in the lesion. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

TMS Seeded Diffusion Tensor Imaging Tractography Predicts Permanent Neurological Deficits.

Surgeons must optimize the onco-functional balance by maximizing the extent of resection and minimizing postoperative neurological morbidity. Optimal patient selection and surgical planning requires preoperative identification of nonresectable structures. Transcranial magnetic stimulation is a method of noninvasively mapping the cortical representations of the speech and motor systems. Despite recent promising data, its clinical relevance and appropriate role in a comprehensive mapping approach remains unknown. In this study, we aim to provide direct evidence regarding the clinical utility of transcranial magnetic stimulation by interrogating the eloquence of TMS points. Forty-two glioma patients were included in this retrospective study. We collected motor function outcomes 3 months postoperatively. We overlayed the postoperative MRI onto the preoperative MRI to visualize preoperative TMS points in the context of the surgical cavity. We then generated diffusion tensor imaging tractography to identify meaningful subsets of TMS points. We correlated the resection of preoperative imaging features with clinical outcomes. The resection of TMS-positive points was significantly predictive of permanent deficits (p = 0.05). However, four out of eight patients had TMS-positive points resected without a permanent deficit. DTI tractography at a 75% FA threshold identified which TMS points are essential and which are amenable to surgical resection. TMS combined with DTI tractography shows a significant prediction of postoperative neurological deficits with both a high positive predictive value and negative predictive value.

Effect of brain normalization methods on the construction of functional connectomes from resting-state functional MRI in patients with gliomas.

PURPOSE: Spatial normalization is an essential step in resting-state functional MRI connectomic analysis with atlas-based parcellation, but brain lesions can confound it. Cost-function masking (CFM) is a popular compensation approach, but may not benefit modern normalization methods. This study compared three normalization methods with and without CFM and determined their impact on connectomic measures in patients with glioma. METHODS: Fifty patients with glioma were included. T1 -weighted images were normalized using three different methods in SPM12, with and without CFM, which were then overlaid on the ICBM152 template and scored by two neuroradiologists. The Dice coefficient of gray-matter correspondence was also calculated. Normalized resting-state functional MRI data were parcellated using the AAL90 atlas to construct an individual connectivity matrix and calculate connectomic measures. The R2 among the different normalization methods was calculated for the connectivity matrices and connectomic measures. RESULTS: The older method (Original) performed significantly worse than the modern methods (Default and DARTEL; P < .005 in observer ranking). The use of CFM did not significantly improve the normalization results. The Original method had lower correlation with the Default and DARTEL methods (R2 = 0.71-0.74) than Default with DARTEL (R2 = 0.96) in the connectivity matrix. The clustering coefficient appears to be the most, and modularity the least, sensitive connectomic measures to normalization performance. CONCLUSION: The spatial normalization method can have an impact on resting-state functional MRI connectome and connectomic measures derived using atlas-based brain parcellation. In patients with glioma, this study demonstrated that Default and DARTEL performed better than the Original method, and that CFM made no significant difference.

Alterations in Functional Connectomics Associated With Neurocognitive Changes Following Glioma Resection.

BACKGROUND: Decline in neurocognitive functioning (NCF) often occurs following brain tumor resection. Functional connectomics have shown how neurologic insults disrupt cerebral networks underlying NCF, though studies involving patients with brain tumors are lacking. OBJECTIVE: To investigate the impact of brain tumor resection upon the connectome and relationships with NCF outcome in the early postoperative period. METHODS: A total of 15 right-handed adults with left perisylvian glioma underwent resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological assessment before and after awake tumor resection. Graph theoretical analysis was applied to rs-fMRI connectivity matrices to calculate network properties. Network properties and NCF measures were compared across the pre- to postoperative periods with matched pairs Wilcoxon signed-rank tests. Associations between pre- to postoperative change in network and NCF measures were determined with Spearman rank-order correlations (ρ). RESULTS: A majority of the sample showed postoperative decline on 1 or more NCF measures. Significant postoperative NCF decline was found across measures of verbal memory, processing speed, executive functioning, receptive language, and a composite index. Regarding connectomic properties, betweenness centrality and assortativity were significantly smaller postoperatively, and reductions in these measures were associated with better NCF outcomes. Significant inverse associations (ρ = -.51 to -.78, all P < .05) were observed between change in language, executive functioning, and learning and memory, and alterations in segregation, centrality, and resilience network properties. CONCLUSION: Decline in NCF was common shortly following resection of glioma involving eloquent brain regions, most frequently in verbal learning/memory and executive functioning. Better postoperative outcomes accompanied reductions in centrality and resilience connectomic measures.

Spinal laser interstitial thermal therapy: single-center experience and outcomes in the first 120 cases.

OBJECTIVE: The objective of this study was to present the results of a consecutive series of 120 cases treated with spinal laser interstitial thermal therapy (sLITT) to manage epidural spinal cord compression (ESCC) from metastatic tumors. METHODS: The electronic records of patients treated from 2013 to 2019 were analyzed retrospectively. Data collected included demographic, pathology, clinical, operative, and imaging findings; degree of epidural compression before and after sLITT; length of hospital stay; complications; and duration before subsequent oncological treatment. Independent-sample t-tests were used to compare means between pre- and post-sLITT treatments. Survival was estimated by the Kaplan-Meier method. Multivariate logistic regression was used to analyze predictive factors for local recurrence and neurological complications. RESULTS: There were 110 patients who underwent 120 sLITT procedures. Spinal levels treated included 5 cervical, 8 lumbar, and 107 thoracic. The pre-sLITT Frankel grades were E (91.7%), D (6.7%), and C (1.7%). The preoperative ESCC grade was 1c or higher in 92% of cases. Metastases were most common from renal cell carcinoma (39%), followed by non-small cell lung carcinoma (10.8%) and other tumors (35%). The most common location of ESCC was in the vertebral body (88.3%), followed by paraspinal/foraminal (7.5%) and posterior elements (4.2%). Adjuvant radiotherapy (spinal stereotactic radiosurgery or conventional external beam radiation therapy) was performed in 87 cases (72.5%), whereas 33 procedures (27.5%) were performed as salvage after radiotherapy options were exhausted. sLITT was performed without need for spinal stabilization in 87 cases (72.5%). Post-sLITT Frankel grades were E (85%), D (10%), C (4.2%), and B (0.8%); treatment was associated with a median decrease of 2 ESCC grades. The local control rate at 1 year was 81.7%. Local control failure occurred in 25 cases (20.8%). The median progression-free survival was not reached, and overall survival was 14 months. Tumor location in the paraspinal region and salvage treatment were independent predictors of local recurrence, with hazard ratios of 6.3 and 3.3, respectively (p = 0.01). Complications were observed in 22 cases (18.3%). sLITT procedures performed in the lumbar and cervical spine had hazard ratios for neurological complications of 15.4 and 17.1 (p < 0.01), respectively, relative to the thoracic spine. CONCLUSIONS: sLITT is safe and provides effective local control for high-grade ESCC from vertebral metastases in the thoracic spine, particularly when combined with adjuvant radiotherapy. The authors propose considering sLITT as an alternative to open surgery in selected patients with spinal metastases.

The use of laser interstitial thermal therapy in the treatment of brain metastases: a literature review.

PURPOSE: The aim of this paper is to discuss the current evidence for Laser Interstitial Thermal Therapy (LITT) in the treatment of brain metastases, our current recommendations for patient selection and the future perspectives for this therapy. We have also touched upon the possible complications and role of systemic therapy coupled with LITT for the treatment of brain metastases. MATERIAL AND METHODS: Two authors carried out the literature search using two databases independently, including PubMed, and Web of Science. The review included prospective and retrospective studies using LITT to treat brain metastases. RESULTS: Twenty-two original articles were analyzed in this review, particularly clinical outcomes and complications. We have also provided our institutional experience in the use of LITT to treat brain metastases and addressed future perspectives for the use of this technology. CONCLUSIONS: The current literature supports LITT as a safe and effective therapy for patients with brain metastases that have failed SRS. Larger studies are still required to better evaluate the use of systemic therapy in concomitance with LITT. New images modalities may enable optimized treatment and outcomes.

The role of resting-state functional MRI for clinical preoperative language mapping.

BACKGROUND: Task-based functional MRI (tb-fMRI) is a well-established technique used to identify eloquent cortex, but has limitations, particularly in cognitively impaired patients who cannot perform language paradigms. Resting-state functional MRI (rs-fMRI) is a potential alternative modality for presurgical mapping of language networks that does not require task performance. The purpose of our study is to determine the utility of rs-fMRI for clinical preoperative language mapping when tb-fMRI is limited. METHODS: We retrospectively reviewed 134 brain tumor patients who underwent preoperative fMRI language mapping. rs-fMRI was post-processed with seed-based correlation (SBC) analysis, when language tb-fMRI was limited. Two neuroradiologists reviewed both the tb-fMRI and rs-fMRI results. Six neurosurgeons retrospectively rated the usefulness of rs-fMRI for language mapping in their patients. RESULTS: Of the 134 patients, 49 cases had limited tb-fMRI and rs-fMRI was post-processed. Two neuroradiologists found rs-fMRI beneficial for functional language mapping in 41(84%) and 43 (88%) cases respectively; Cohen's kappa is 0.83, with a 95% confidence interval (0.61, 1.00). The neurosurgeons found rs-fMRI "definitely" useful in 26 cases (60%) and "somewhat" useful in 13 cases (30%) in locating potential eloquent language centers of clinical interest. Six unsuccessful rs-fMRI cases were due to: head motion (2 cases), nonspecific functionality connectivity outside the posterior language network (1 case), and an unknown system instability (3 cases). CONCLUSIONS: This study is a proof of concept that shows SBC rs-fMRI may be a viable alternative for clinical language mapping when tb-fMRI is limited.

Laser Interstitial Thermal Therapy in the treatment of brain metastases and radiation necrosis.

Stereotactic Radiosurgery has become the main treatment for patients with limited number of brain metastases (BM). Recently, with the increasing use of this modality, there is a growth in recurrence cases. Recurrence after radiation therapy can be divided in changes favoring either tumor recurrence or radiation necrosis (RN). Laser Interstitial Thermal Therapy (LITT) is minimally invasive treatment modality that has been used to treat primary and metastatic brain tumors. When associated with real-time thermometry using Magnetic Resonance Imaging, the extent of ablation can be controlled to provide maximum coverage and avoid eloquent areas. The objective of this study was to investigate the use of LITT in the treatment of BM. An extensive review of the relevant literature was conducted and the outcome results are discussed. There is an emphasis on safety and local control rate of patients treated with this modality. The findings of our study suggest that LITT is a viable safe technique to treat recurrent BM, especially in patients with deep-seated lesions where surgical resection is not an option.

Language supplementary motor area syndrome correlated with dynamic changes in perioperative task-based functional MRI activations: case report.

Supplementary motor area (SMA) syndrome is well known; however, the mechanism underlying recovery from language SMA syndrome is unclear. Herein the authors report the case of a right-handed woman with speech aphasia following resection of an oligodendroglioma located in the anterior aspect of the left superior frontal gyrus. The patient exhibited language SMA syndrome, and functional MRI (fMRI) findings 12 days postoperatively demonstrated a complete shift of blood oxygen level-dependent (BOLD) activation to the contralateral right language SMA/pre-SMA as well as coequal activation and an increased volume of activation in the left Broca's area and the right Broca's homolog. The authors provide, to the best of their knowledge, the first description of dynamic changes in task-based hemispheric language BOLD fMRI activations across the preoperative, immediate postoperative, and more distant postoperative settings associated with the development and subsequent complete resolution of the clinical language SMA syndrome.

Predictors of Local Control of Brain Metastasis Treated With Laser Interstitial Thermal Therapy.

BACKGROUND: 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.