Effect of high-field iMRI guided resection in cerebral glioma surgery: A randomized clinical trial

BACKGROUND

Extent of resection (EOR) in glioma contributes to longer survival. The purpose of NCT01479686 was to prove whether intraoperative magnetic resonance imaging (iMRI) increases EOR in glioma surgery and benefit survival.

METHODS

Patients were randomized (1:1) to receive the iMRI (n = 161) or the conventional neuronavigation (n = 160). The primary endpoint was gross total resection (GTR); secondary outcomes reported were progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

188 high-grade gliomas (HGGs) and 133 low-grade gliomas (LGGs) were enrolled. GTR was 83.85% in the iMRI group vs. 50.00% in the control group (P < 0.0001). In 321 patients, the median PFS (mPFS) was 65.12 months in the iMRI group and 61.01 months in the control group (P = 0.0202). For HGGs, mPFS was improved in the iMRI group (19.32 vs. 13.34 months, P = 0.0015), and a trend of superior OS compared with control was observed (29.73 vs. 25.33 months, P = 0.1233). In the predefined eloquent area HGG subgroup, mPFS, and mOS were 20.47 months and 33.58 months in the iMRI vs. 12.21 months and 21.16 months in the control group (P = 0.0098; P = 0.0375, respectively). From the exploratory analyses of HGGs, residual tumor volume (TV) < 1.0 cm3 decreased the risk of survival (mPFS: 18.99 vs. 9.43 months, P = 0.0055; mOS: 29.77 vs. 18.10 months, P = 0.0042). LGGs with preoperative (pre-OP) TV > 43.1 cm3 and postoperative (post-OP) TV > 4.6 cm3 showed worse OS (P= 0.0117) CONCLUSIONS: It showed that iMRI significantly increased EOR and indicated survival benefits for HGGs, particularly eloquent HGGs. Residual TV in either HGGs or LGGs is a prognostic factor for survival.

Sex-specific molecular differences in glioblastoma: assessing the clinical significance of genetic variants

Introduction

Glioblastoma multiforme (GBM) is one of the most aggressive types of brain cancer, and despite rigorous research, patient prognosis remains poor. The characterization of sex-specific differences in incidence and overall survival (OS) of these patients has led to an investigation of the molecular mechanisms that may underlie this dimorphism.

Methods

We reviewed the published literature describing the gender specific differences in GBM Biology reported in the last ten years and summarized the available information that may point towards a patient-tailored GBM therapy.

Results

Radiomics analyses have revealed that imaging parameters predict OS and treatment response of GBM patients in a sex-specific manner. Moreover, gender-based analysis of the transcriptome GBM tumors has found differential expression of various genes, potentially impacting the OS survival of patients in a sex-dependent manner. In addition to gene expression differences, the timing (subclonal or clonal) of the acquisition of common GBM-driver mutations, metabolism requirements, and immune landscape of these tumors has also been shown to be sex-specific, leading to a differential therapeutic response by sex. In male patients, transformed astrocytes are more sensitive to glutaminase 1 (GLS1) inhibition due to increased requirements for glutamine uptake. In female patients, GBM is more sensitive to anti-IL1β due to an increased population of circulating granulocytic myeloid-derived suppressor cells (gMDSC).

Conclusion

Moving forward, continued elucidation of GBM sexual dimorphism will be critical in improving the OS of GBM patients by ensuring that treatment plans are structured to exploit these sex-specific, molecular vulnerabilities in GBM tumors.

TP53-PTEN-NF1 depletion in human brain organoids produces a glioma phenotype in vitro

Glioblastoma (GBM) is fatal and the study of therapeutic resistance, disease progression, and drug discovery in GBM or glioma stem cells is often hindered by limited resources. This limitation slows down progress in both drug discovery and patient survival. Here we present a genetically engineered human cerebral organoid model with a cancer-like phenotype that could provide a basis for GBM-like models. Specifically, we engineered a doxycycline-inducible vector encoding shRNAs enabling depletion of the TP53, PTEN, and NF1 tumor suppressors in human cerebral organoids. Designated as inducible short hairpin-TP53-PTEN-NF1 (ish-TPN), doxycycline treatment resulted in human cancer-like cerebral organoids that effaced the entire organoid cytoarchitecture, while uninduced ish-TPN cerebral organoids recapitulated the normal cytoarchitecture of the brain. Transcriptomic analysis revealed a proneural GBM subtype. This proof-of-concept study offers a valuable resource for directly investigating the emergence and progression of gliomas within the context of specific genetic alterations in normal cerebral organoids.

Surgical management of metastatic Hürthle cell carcinoma to the skull base, cortex, and spine: illustrative case

BACKGROUND

Hürthle cell carcinoma (HCC) is an unusual and aggressive variant of the follicular type of differentiated thyroid cancer (DTC), accounting for less than 3% of DTCs but posing the highest risk of metastasis. Brain metastases are uncommonly reported in the literature but pose a poor prognosis. The low rate of brain metastases from HCC coupled with ambiguous treatment protocols for the extracranial disease complicate successful disease management and definitive treatment strategy. The authors present the case of a patient with HCC metastasis to the skull base, cortex, and spine with recent tibial metastasis.

OBSERVATIONS

Despite the presence of metastasis to the cortex, skull base, and spine, the patient responded very well to radiation therapy, sellar mass resection, and cervical spine decompression and fixation and has made a remarkable recovery.

LESSONS

The authors' multidisciplinary approach to the patient's care, including a diverse team of specialists from oncology, neurosurgery, orthopedic surgery, radiology, endocrinology, and collaboration with clinical trial researchers, was fundamental to her successful outcome, demonstrating the utility of intersecting specialties in successful outcomes in neuro-oncological patient care.

Robustness of Randomized Control Trials Supporting Current Neurosurgery Guidelines

BACKGROUND

Treatment guidelines in neurosurgery are often based on evidence obtained from randomized controlled trials (RCTs).

OBJECTIVE

To evaluate the robustness of RCTs supporting current central nervous tumor and cerebrovascular disease guidelines by calculating their fragility index (FI)-the minimum number of patients needed to switch from an event to nonevent outcome to change significant trial primary outcome.

METHODS

We analyzed RCTs referenced in the Congress of Neurological Surgeons and American Association of Neurological Surgeons guidelines on central nervous tumor and cerebrovascular disease management. Trial characteristics, finding of a statistically significant difference in the primary endpoint favoring the experimental intervention, the FI, and FI minus number lost to follow-up were assessed.

RESULTS

Of 312 RCTs identified, 158 (50.6%) were published from 2000 to 2010 and 106 (34%) after 2010. Sixty-three trials (19.2%) were categorized as surgical trials, and the rest studied medical treatment (82.0%) or percutaneous intervention (8.33%). The trials had a median power of 80.0% (IQR 80.0-90.0). Of these, 120 trials were eligible for FI calculation. The median FI was 7.0 (IQR 2.0-16.25). Forty-four (36.6%) trials had FI ≤ 3 indicating very low robustness. After adjusting for covariates, recently published trials and trials studying percutaneous interventions were associated with significantly higher FI compared with older trials and trials comparing surgical approaches, respectively. Trials limited to single centers were associated with significantly lower FI.

CONCLUSION

Trials supporting current guidelines on neuro-oncological and neurovascular surgical interventions have low robustness. While the robustness of trials has improved over time, future guidelines must take into consideration this metric in their recommendations.

Fractionated Radiotherapy After Gross Total Resection of Clival Chordoma: A Systematic Review of Survival Outcomes

BACKGROUND

Current treatment guidelines for clival chordomas recommend surgical resection followed by high-dose radiotherapy (RT). However, in patients in whom gross total resection (GTR) is achieved, the benefits of additional RT remain unclear.

OBJECTIVE

To investigate whether RT offers any benefit to progression-free survival (PFS) in patients undergoing GTR of clival chordoma by performing a systematic review of all currently published literature.

METHODS

A total of 5 databases were searched to include all studies providing data on GTR ± RT for clival chordomas (January 1990-June 2021). Qualitative assessment was performed with Newcastle-Ottawa Scale guidelines for assessing quality of nonrandomized studies. Statistical analysis using individualized patient data of PFS was performed.

RESULTS

The systematic search yielded 2979 studies, weaned to 22 full-text articles containing 108 patients. All patients underwent GTR of clival chordoma, with 46 (43%) patients receiving adjuvant RT. Mean PFS for RT patients was 31.09 months (IQR: 12.25-37.75) vs 54.92 months (IQR: 14.00-85.75) in non-RT patients. Overall, RT did not increase PFS (HR 0.320, P = .069) to a value that achieved statistical significance. Stratifying by photon therapy vs particle beam therapy yielded no statistically significant benefit for particle beam therapy for PFS ( P = .300). Of patients with age ≥65 years, RT did not improve outcomes to statistical significance for PFS (HR 0.450, P = .481). Patients age ≥65 years had lower PFS on both bivariate analysis (HR 3.708, P = .007) and multivariate analysis (HR 3.322, P = .018).

CONCLUSION

After achieving GTR of clival chordoma, fractionated RT offers unclear benefit upon survival outcomes.

Radiotherapy Is Associated With Improved Overall Survival in Adult Pineoblastoma: A SEER Database Analysis

OBJECTIVE

Pineoblastomas (PBLs) are rare high-grade tumors treated variably with surgery and/or radiation. The role of surgical extent of resection and radiotherapy (RT) in adult PBL remains unclear. We queried the Surveillance, Epidemiology, and End Results (SEER) database to assess these variables' effects on overall survival (OS) in adult PBL.

METHODS

The SEER (1975-2016) database was queried for adult patients with diagnosis of PBL (ICD-0-3: 9362/3). Variables extracted included age, sex, race, geographical region, extent of tumor resection, RT, chemotherapy (CT), and OS data. Comparisons were performed with the χ² test for categorical variables, Cox proportional hazards models to assess the association of clinical variables on OS, and Kaplan-Meier curves were generated.

RESULTS

A total of 201 patients with PBL were identified with mean age 40.0 years (interquartile range 27.0-51.0) and most patients being male (53%) and Caucasian (77%). 101 (50%) patients received RT, and gross total resection was achieved in 83 (41%). Age stratification by decade revealed statistically significant poorer OS in patients aged ≥70 years. In bivariate analysis, RT with or without surgery was associated with improved 5-year OS compared with no RT (77.3% vs. 63.2%, P = 0.020). In multivariate analysis, age was a poor prognostic factor for OS (P < 0.001) and RT did appear to improve survival (P = 0.020). Extent of surgical resection was not significantly associated with improved survival.

CONCLUSIONS

In adult patients with PBL, RT may offer an OS benefit irrespective of surgery or extent of surgical resection. Patients ≥70 years of age are associated with poorer OS.

Mini-temporal approach as an alternative to the classical pterional approach for resective temporal region surgeries

Background

Classical pterional appoach for temporal surgeries may cause atrophy and dysfunction of temporalis, injury to the facial nerve, and unnecessary cortical exposure. As an alternative to the classical pterional approach for such surgeries, we hereby describe an mini-temporal approach which reduces these risks and proven to be practical in neurological surgeries.

Material and methods

In the mini-temporal incision design, the frontal end of the incision never surpassed the hairline at the level of temporal line, and a one-layer skin-galea-muscle flap was detached from the cranium, effectively avoiding the injuries of facial nerve. The surgical bone window was completely located underneath the temporalis muscle, allowing it to be completely repositioned postoperatively.

Results

We demonstrated the application of mini-temporal approach in a variety of temporal region tumors, which can be applied to complete successful resective surgeries while effectively reducing injuries to extra-temporal cortex, temporalis, and facial nerve. There were no postoperative complications related to extra-temporal cortical damage, atrophy of temporalis, or injury to the facial nerve.

Conclusion

The mini-temporal approach can effectively shorten the time of craniotomy and closure, decrease the size of bony removal, increase the restoration of temporalis during closure, and lower the chance of facial nerve injury. Therefore, it improves cosmetic outcomes and reduces the risk of unintentional extra-temporal cortical injury, which fully embodies the minimally invasive principle in neurosurgery.

The Intraoperative Utilization of Multimodalities Could Improve the Prognosis of Adult Glioblastoma: A Single-Center Observational Study

OBJECTIVE

In recent years, numerous neurosurgical multimodal techniques have been utilized to maximize tumor resection safely and effectively. However, the synergetic effects of neurosurgical multimodalities on the survival of glioblastoma patients remain unclear. This study evaluated the role of intraoperative utilization of multimodalities in glioblastoma patients.

METHODS

Data of 912 adult patients with glioblastoma were obtained from the Huashan Glioma Registry. The utilization of fewer than 2 (multimodality value < 2) intraoperative multimodal techniques was defined as the nonmultimodal group. In contrast, the utilization of 2 or more (multimodality value ≥ 2) intraoperative multimodal techniques was regarded as the multimodal group. The prognosis of the 2 cohorts was compared and further stratified based on the diagnosis date (2010-2014 or 2015-2019) to reveal the role of the application of multimodal techniques.

RESULTS

The median overall survival (OS) and progression-free survival of glioblastoma patients were 17.70 months and 12.03 months, respectively. The OS time of the multimodal group was noticeably longer than that of the nonmultimodal group (21.0 months vs. 16.0 months, P < 0.001). Multimodal techniques were more frequently applied in surgery in the 2015-2019 group than in the 2010-2014 group. The popularity of multimodal techniques contributed to significant improvement in the prognosis of glioblastoma patients from 2010-2014 to 2015-2019 (OS, 16.0 months vs. 22.0 months, P < 0.001).

CONCLUSIONS

This study indicated that the utilization of intraoperative multimodal techniques improved the extent of resection and elevated the survival for adult glioblastoma patients.

Electrical stimulation-induced speech-related negative motor responses in the lateral frontal cortex

OBJECTIVE

Speech arrest is a common but crucial negative motor response (NMR) recorded during intraoperative brain mapping. However, recent studies have reported nonspeech-specific NMR sites in the ventral precentral gyrus (vPrCG), where stimulation halts both speech and ongoing hand movement. The aim of this study was to investigate the spatial relationship between speech-specific NMR sites and nonspeech-specific NMR sites in the lateral frontal cortex.

METHODS

In this prospective cohort study, an intraoperative mapping strategy was designed to identify positive motor response (PMR) sites and NMR sites in 33 consecutive patients undergoing awake craniotomy for the treatment of left-sided gliomas. Patients were asked to count, flex their hands, and simultaneously perform these two tasks to map NMRs. Each site was plotted onto a standard atlas and further analyzed. The speech and hand motor arrest sites in the supplementary motor area of 2 patients were resected. The 1- and 3-month postoperative language and motor functions of all patients were assessed.

RESULTS

A total of 91 PMR sites and 72 NMR sites were identified. NMR and PMR sites were anteroinferiorly and posterosuperiorly distributed in the precentral gyrus, respectively. Three distinct NMR sites were identified: 24 pure speech arrest (speech-specific NMR) sites (33.33%), 7 pure hand motor arrest sites (9.72%), and 41 speech and hand motor arrest (nonspeech-specific NMR) sites (56.94%). Nonspeech-specific NMR sites and speech-specific NMR sites were dorsoventrally distributed in the vPrCG. For language function, 1 of 2 patients in the NMA resection group had language dysfunction at the 1-month follow-up but had recovered by the 3-month follow-up. All patients in the NMA resection group had fine motor dysfunction at the 1- and 3-month follow-ups.

CONCLUSIONS

The study results demonstrated a functional segmentation of speech-related NMRs in the lateral frontal cortex and that most of the stimulation-induced speech arrest sites are not specific to speech. A better understanding of the spatial distribution of speech-related NMR sites will be helpful in surgical planning and intraoperative mapping and provide in-depth insight into the motor control of speech production.

Peripheral access size evaluation in transfemoral transcatheter aortic valve replacement

BACKGROUND/AIM

Peripheral access vessel dimensions in the general patient population screened for transcatheter aortic valve replacement (TAVR) can offer insight into the indications for pre-TAVR computed tomography angiography (CTA) assessment. We seek to determine peripheral access vessel sizes in patients screened for TAVR and association with patient characteristics.

MATERIALS AND METHODS

All patients with severe, symptomatic aortic stenosis screened for TAVR at a high-volume center from April 2012 to March 2019 were retrospectively reviewed. For each patient, contrast-enhanced CTA was used to determine the minimal luminal diameters (MLDs) of the transfemoral access vessels, as measured between the inguinal ligament and the deep femoral artery for the femoral artery, and proximal to the inguinal ligament for the external and common iliac arteries, respectively. Paired and independent samples t-tests were used to compare means and regression analyses were performed to determine factors associated with MLD.

RESULTS

A total of 1049 screened patients were included of which 826 (78.7%) underwent TAVR and 551 (52.5%) were male. The mean age was 80.6 (±9.6) years and the mean body mass index (BMI) was 26.7 (±5.9) kg/m² . About 152 (14.5%) had peripheral vascular disease and 153 (14.6%) had chronic kidney disease. The mean (±2 standard deviations) MLDs of the right and left femoral arteries were 7.73 mm (4.68-10.78) and 7.68 mm (4.63-10.72), respectively. Male sex and BMI were associated with larger average femoral MLD while hyperlipidemia, hypertension, smoking, peripheral vascular disease, and coronary artery disease were inversely associated.

CONCLUSION

Most patients screened for TAVR have minimum peripheral access vessel sizes exceeding the recommended minimum access route diameters of modern transcatheter heart valves. As sheath sizes decrease, clinicians must carefully judge patient individual risk factors to determine whether a pre-TAVR CTA assessing peripheral access vessel dimensions and anatomical contraindications is indicated. Larger studies and randomized controlled trials are required to compare the outcomes of TAVR with and without preoperative CTA.

Alternate accesses for transcatheter aortic valve replacement: A network meta-analysis

BACKGROUND

When transfemoral (TF) access is contraindicated in patients undergoing transcatheter aortic valve replacement (TAVR), alternate access strategies are considered. The choice of one alternate access over the other remains controversial.

METHODS

Following a comprehensive literature search, studies comparing any combination of TF, transapical (TA), transaortic (TAo), transcarotid (TC), and trans-subclavian (TS) TAVR were identified. Data were pooled using fixed- and random-effects network meta-analysis. Rank scores with probability ranks of different treatment groups were calculated.

RESULTS

Eighty-four studies (26,449 patients) were included. Compared to TF access, TA and TAo accesses were associated with higher 30-day mortality (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.31-1.94; OR 1.79, 95% CI 1.21-2.66, respectively), while the TC and TS showed no difference (OR 1.12, 95% CI 0.64-1.95; OR 1.23, 95% CI 0.67-2.27, respectively); TF access ranked best followed by TC. There was no significant difference in 30-day stroke; TC access ranked best followed by TS. At a weighted mean follow-up of 1.6 years, TA and TAo accesses were associated with higher long-term mortality versus TF (incidence rate ratio [IRR] 1.31, 95% CI 1.18-1.45; IRR 1.41, 95% CI 1.11-1.79, respectively); there was no difference between TC and TS versus TF access (IRR 1.02, 95% CI 0.70-1.47; IRR 1.16, 95% CI 0.82-1.66, respectively); TF access ranked best followed by TC. At a weighted mean follow-up of 1.4 years, only TA access was associated with higher long-term stroke compared to TF (IRR 3.01, 95% CI 1.15-7.87); TF access ranked as the best strategy followed by TAo.

CONCLUSION

TC and TS approaches are associated with superior postoperative outcomes compared to other TAVR alternate access strategies. Randomized trials definitively assessing the safety and efficacy of alternate access strategies are needed.

The prognosis of glioblastoma: a large, multifactorial study

OBJECTIVE

Glioblastoma is the most common and fatal primary brain tumor in adults. Even with maximal resection and a series of postoperative adjuvant treatments, the median overall survival (OS) of glioblastoma patients remains approximately 15 months. The Huashan Hospital glioma bank contains more than 2000 glioma tissue samples with long-term follow-up data; almost half of these samples are from glioblastoma patients. Several large glioma databases with long-term follow-up data have reported outcomes of glioblastoma patients from countries other than China. We investigated the prognosis of glioblastoma patients in China and compared the survival outcomes among patients from different databases.

METHODS

The data for 967 glioblastoma patients who underwent surgery at Huashan Hospital and had long-term follow-up records were obtained from our glioma registry (diagnosed from 29 March 2010, through 7 June 2017). Patients were eligible for inclusion if they underwent surgical resection for newly diagnosed glioblastomas and had available data of survival and personal information. Data of 778 glioblastoma patients were collected from three separate online databases (448 patients from The Cancer Genome Atlas (TCGA, https://cancergenome.nih.gov), 191 from REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT) database (GSE108476) and 132 from data set GSE16011(Hereafter called as the French database). We compared the prognosis of glioblastoma patients from records among the different databases and the changes in survival outcomes of glioblastoma patients from Huashan Hospital over an 8-year period.

RESULTS

The median OS of glioblastoma patients was 16.3 (95% CI: 15.4-17.2) months for Huashan Hospital, 13.8 (95% CI: 12.9-14.9) months for TCGA, 19.3 (95% CI: 17.0-20.0) months for the REMBRANDT database, and 9.1 months for the French database. The median OS of glioblastoma patients from Huashan Hospital improved from 15.6 (2010-2013, 95% CI: 14.4-16.6) months to 18.2 (2014-2017, 95% CI: 15.8-20.6) months over the study period (2010-2017). In addition, the prognosis of glioblastoma patients with total resection was significantly better than that of glioblastoma patients with sub-total resection or biopsy.

CONCLUSIONS

Our study confirms that treatment centered around maximal surgical resection brought survival benefits to glioblastoma patients after adjusting to validated prognostic factors. In addition, an improvement in prognosis was observed among glioblastoma patients from Huashan Hospital over the course of our study. We attributed it to the adoption of a new standard of neurosurgical treatment on the basis of neurosurgical multimodal technologies. Even though the prognosis of glioblastoma patients remains poor, gradual progress is being made.

Systematic Assessment of Online Health Information for Coronary Revascularization

This cross-sectional study examines the readability, accuracy, content, quality, and suitability of online health information on coronary artery bypass grafting or percutaneous coronary intervention for patients.

A Novel Intraoperative Brain Mapping Integrated Task-Presentation Platform

BACKGROUND

To be efficient, intraoperative task-presentation systems must accurately present various language and cognitive tasks to patients undergoing awake surgery, and record behavioral data without compromising convenience of surgery.

OBJECTIVE

To present an integrated brain mapping task-presentation system we developed and evaluate its effectiveness in intraoperative task presentation.

METHODS

The Brain Mapping Interactive Stimulation System (Brain MISS) is a flexible task presentation system that adjusts for patient comfort, needs of the surgeon, and operating team, with multivideo recording for patients' behavior. A total of 48 patients from 3 centers underwent intraoperative language task test during awake brain surgery with the Brain MISS. Each patient was assigned 5 questions each on picture naming, reading, and listening comprehension before and during awake surgeries. The accuracy of intraoperative stimulus-response (without electrical stimulation) was recorded. The Brain MISS was to be considered effective, if the lower limit of 95% CI of patients' intraoperative response was ≥80% and also if the accuracy of intraoperative response of all patients was statistically higher than 80%.

RESULTS

All patients successfully underwent intraoperative assessment with the Brain MISS. The overall accuracy of stimulus response was 95.8% (95% CI 90.18%-100.00%), with the lower limit being higher than 80% and the response accuracy also significantly being higher than 80% in all patients (P = .006).

CONCLUSION

The Brain MISS is a portable and effective system for presenting and streamlining complicated language and cognitive tasks during awake surgery. It can also record standardized patient response data for neuroscientific research.

The basal turning point of optic radiation (bTPOR): The location of optic radiation in the cerebral basal surface

BACKGROUNDS

Optic radiation protection is crucial in the basal temporal approach to the mesial temporal lobe. Clear description of the optic radiation in the basal brain surface is lacking. Our aim is to describe the anatomy of optic radiation in the basal cerebral surface and define safety zone of basal temporal approach avoiding of optic radiation injury.

METHODS

Five brain specimens (10 hemispheres) were dissected using Klingler method to observe the course of the optic radiation. Diffusion tensor imaging data of 25 volunteers were used to verify the fiber dissection results. The relationship of the optic radiation to nearby structures were illustrated and measured.

RESULTS

The optic radiation bends from the lateral wall of the lateral ventricle to its bottom at a basal turning point of optic radiation (bTPOR). The bTPOR is at the plane crossing the center point of the splenium of corpus callosum. MRI measurements showed no significant difference in the distance from the center of the splenium of corpus callosum and the bTPOR to the occipital pole (59.46 ± 4.338 mm vs 59.54 ± 3.805 mm, p = 0.95). Anterior to bTPOR, no optic radiation fibers were found at the basal brain surface.

CONCLUSIONS

The bTPOR was found as a landmark of the optic radiation in the cerebral basal surface. With neuronavigation, the splenium of corpus callosum can be a landmark of the bTPOR. By approaching mesial temporal lesions using the basal temporal approach anterior to bTPOR, optic radiation injury can be prevented.

Artificial intelligence neuropathologist for glioma classification using deep learning on hematoxylin and eosin stained slide images and molecular markers

BACKGROUND

Pathological diagnosis of glioma subtypes is essential for treatment planning and prognosis. Standard histological diagnosis of glioma is based on postoperative hematoxylin and eosin stained slides by neuropathologists. With advancing artificial intelligence (AI), the aim of this study was to determine whether deep learning can be applied to glioma classification.

METHODS

A neuropathological diagnostic platform is designed comprising a slide scanner and deep convolutional neural networks (CNNs) to classify 5 major histological subtypes of glioma to assist pathologists. The CNNs were trained and verified on over 79 990 histological patch images from 267 patients. A logical algorithm is used when molecular profiles are available.

RESULTS

A new model of the squeeze-and-excitation block DenseNet with weighted cross-entropy (named SD-Net_WCE) is developed for the glioma classification task, which learns the recognizable features of glioma histology CNN-based independent diagnostic testing on data from 56 patients with 17 262 histological patch images demonstrated patch level accuracy of 86.5% and patient level accuracy of 87.5%. Histopathological classifications could be further amplified to integrated neuropathological diagnosis by 2 molecular markers (isocitrate dehydrogenase and 1p/19q).

CONCLUSION

The model is capable of solving multiple classification tasks and can satisfactorily classify glioma subtypes. The system provides a novel aid for the integrated neuropathological diagnostic workflow of glioma.

Germline ALK variations are associated with a poor prognosis in glioma and IDH-wildtype glioblastoma

BACKGROUND

Glioma is the most common primary brain tumor. Clear classification is crucial for accurate diagnosis and individualized treatment. Histopathological characteristics and genetic alterations have shown to be related to prognosis and treatment response. Germline variants are important components of genetic alterations. However, the distribution of germline variations in glioma patients and their association with survival remain unknown.

METHODS

We carried out whole-exome sequencing on 99 cases to explore germline variants in glioma. We also analyzed the association of germline variants with clinicopathological features and other prognostic indicators.

RESULTS

All the glioma cases harbored rare germline variants. Germline ALK variants (gALK-Mut) were identified in 12/99 (12.12%) patients. The gALK-Mut patients had significantly shorter overall survival than germline ALK wildtype (gALK-WT) patients in the all glioma group (99 cases) and the subset of patients with IDH-wildtype glioblastoma (IDH-WT-GBM, 39 cases) (P = 0.013 and 0.027, respectively). The gALK-Mut patients also had higher frequency of BIRC5, PIK3CA and RPN1 somatic mutations than the gALK-WT patients in IDH-WT-GBM. Other confounding factors appeared to contribute to patient survival. The subgroup of patients in IDH-WT-GBM with gALK-Mut/TP53-Mut had worse prognosis than the gALK-WT/TP53-Mut subgroup (P = 0.031); The gALK-Mut/TERT-WT and gALK-Mut/TERT-Mut subgroups both had a worse prognosis than the gALK-WT/TERT-Mut subgroup (P = 0.031 and 0.018, respectively).

CONCLUSIONS

Our study revealed ALK variation was an independent indicator of poor prognosis in glioma and IDH-WT-GBM. It could be a promising biomarker and tractable therapeutic target for this deadly disease.

Impact of a pandemic on surgical neuro-oncology-maintaining functionality in the early phase of crisis

Background

The Coronavirus disease 2019 (COVID-19) pandemic has extraordinarily impacted global healthcare. Neuro-oncological surgery units have peculiar features that make them highly relevant in the strategic reaction to the pandemic. In this Chinese Society of Neuro-Oncology (CSNO) initiated survey, we appraise the changes implemented in neuro-oncological surgery hospitals across different Asian countries and provide expert recommendations for responses at different stages of the pandemic.

Methods

We performed a 42-question survey of the early experience of neuro-oncological surgery practice in hospitals across different Asian countries on April 1, 2020, with responses closed on April 18, 2020.

Results

144 hospitals completed the questionnaire. Most were in WHO post-peak phase of the pandemic and reported a median reduction in neuro-oncological surgery volume of 25–50%. Most (67.4%) resumed elective surgery in only COVID-19 negative patients;11.1% performed only emergency cases irrespective of COVID-19 status;2.1% suspended all surgical activity. Ninety-one (63.2%) relocated personnel from neurosurgery to other departments. Fifty-two (36.1%) hospitals suspended post-operative adjuvant therapy and 94 (65.2%) instituted different measures to administer post-operative adjuvant therapy. Majority (59.0%) of the hospitals suspended research activity. Most (70%) respondents anticipate that current neurosurgery restrictions will continue to remain for > 1 month.

Conclusions

Majority of the respondents to our survey reported reduced neuro-oncological surgery activity, policy modification, personnel reallocation, and curtailment of educational/research activities in response to the COVID-19 pandemic. The persistent widespread interruption of surgical neuro-oncology in even post-peak phases of the pandemic raises serious concerns about the long-term impact of the pandemic on neuro-oncological patients and highlights the essence of timely measures for pandemic preparedness, patient triage, and workforce protection.

Infraoccipital Supratentorial Approach Resection of a Left Mesiotemporal and Atrium Epidermoid Cyst

Classically mesiotemporal lesions are approached from the lateral temporal approach, which frequently injures the visual and language tracts. We present the posterior approach through which the language tracts and visual tracts at the roof and lateral wall of the temporal horn (Meyer loop) can be avoided, minimizing the risk of neurologic injury. The patient, a 32-year-old man, presented with the chief complaint of experiencing seizures for 6 years with rare, generalized, tonic-clonic seizures. Physical examination showed no neurologic deficits and past medical history was not remarkable. Magnetic resonance imaging revealed a left mesiotemporal lesion, which showed no contrast enhancement and infiltrated the atrium. For surgery, the patient was laid in prone position and a tailored bone flap was lifted. Next the occipital lobe was retracted gently to expose the lesion. Penfield dissectors were used to gradually resect the lesion. The roof and inner wall of the atrium were exposed during resection. These structures were protected. Residues of the lesion and its capsule were seen attached to the lateral ventricle and were carefully coagulated and removed. The hippocampus was also exposed and a small segment resected. Exposure of the roof and inner wall of the atrium confirmed that the entire lesion has been resected. Intraoperative magnetic resonance imaging evaluation confirmed a total resection of the lesion. Pathological analysis confirmed the diagnosis of epidermoid cyst. Cognitive evaluation results showed no postoperative deficiencies and his visual field was also not affected by the surgery. Informed patient content was obtained (Video 1).

Hemodynamic Scaling of Task-Induced Signal Changes in Tumor Subjects

Background: FMRI signal amplitude can change during stimulus presentation due to underlying neural function and hemodynamic responses limiting the accuracy of fMRI in pre-surgical planning. To account for these changes in fMRI activation signal, we used breath-hold tasks to mimic hemodynamic changes in brain tumor subjects and scaled the activation response.

Methods: Motor and/or language fMRI was performed in 21 subjects with brain tumor. A breath-hold task was also performed in these subjects to obtain the hemodynamic response changes independent of neural changes. The task activation signals were calibrated on a voxel wise basis for all the subjects. Direct cortical stimulation was used to verify the scaled results of task-based fMRI.

Results: After scaling for the hemodynamic response function (HRF) on a voxel wise basis, the spatial extent of the scaled activation was more clustered together and appeared to minimize false positives. Similarly, accounting for the underlying canonical HRF, the percentage increase of active voxels after scaling had lower standard non-deviation suggesting that the activation response across voxels were more similar.

Conclusion: Although preliminary in nature, this study suggests that the variation in hemodynamic changes can be calibrated using breath-hold in brain tumor subjects and can also be used for other clinical cases where the underlying HRF has been altered.

Temporoinsular Glioma Resection under Awake Mapping: 2-Dimensional Operative Video

Temporoinsular gliomas are frequently large-sized tumors that require meticulous planning to ensure maximum surgical resection and minimal neurologic deficits in patients. Here, we demonstrate our technique encompassing multi-modal imaging guidance and awake brain mapping which enables maximum safe resection of such tumors. The patient, a 39-yr-old man, presented with depression and memory loss for 18 mo. Preoperative magnetic resonance imaging (MRI; MAGNETOM Verio, Siemens) revealed a nonenhancing lesion in the left dominant temporoinsular lobe. Three-dimensional magnetic resonance spectroscopy was used to analyze the choline/N-acetyl-aspartate index which suggested a low-grade glioma diagnosis. Informed patient consent was obtained. After craniotomy, the mouth motor, speech arrest, and word generation areas were mapped via direct cortical stimulation under awake mapping. A strip electrode was placed across the precentral gyrus for continuous motor evoked potential monitoring. Cortical incisions were made in nonfunctional cortical areas and tumor was resected in the temporal lobe. Following this, tumor at the inferior insular zone was carefully debunked with Cavitron Ultrasonic Surgical Aspirator (Integra Lifescience) also through the temporal window. The hippocampus was preserved since it was not invaded by tumor. Subcortical mapping combined with Diffuse Tensor Imaging tractography-based navigation (Medtronic lnc.) was performed to localize the motor and language pathways. Intraoperative MRI evaluation showed tumor resection extent of 95%. Pathological and molecular analysis revealed a diagnosis of Grade II IDH-mutant oligodendroglioma. After surgery the patient was administered chemotherapy (Temozolomide). He recovered without language or motor deficits.

UCP2 silencing in glioblastoma reduces cell proliferation and invasiveness by inhibiting p38 MAPK pathway

Uncoupling protein-2 (UCP2) is a mitochondrial inner membrane anion carrier and is emerging as a negative regulator of ROS production. Overexpression of UCP2 has been detected in various tumors, but its role in glioblastoma remains unclear. Using tissue microarrays and interrogations of public databases, we explored that the expression of UCP2 is upregulated in glioma, especially in GBM, and overexpression of UCP2 correlates with poor prognosis in glioma patients. To further reveal the role of UCP2 in glioma, UCP2-slienced cell lines (U251, U87MG and A172) by lentivirus were constructed to study how silenced UCP2 expression affects cellular functions in vitro, and tumorigenicity in vivo. RNA-Seq based genome and pathway analysis were performed to elucidate the underlying mechanisms of action of UCP2. Our results revealed that UCP2 silenced glioma cells show inhibited migration, invasiveness, clonogenicity, proliferation, promoted cell apoptosis in vitro, and weaker tumorigenicity in nude mice. Transcriptome analysis suggested a UCP2-dependent regulation of p38 MAPK (Mitogen-activated protein kinase) signaling networks, which was further validated by qRT-PCR and Western blot. Our research provides a new insight into the biological significance of UCP2 in glioma and its potential application in treatment and diagnosis.

Silencing expression of PHF14 in glioblastoma promotes apoptosis, mitigates proliferation and invasiveness via Wnt signal pathway

Background

The plant homeodomain (PHD) finger protein 14 (PHF14) is a vital member of PHD finger protein families. Abnormal expression of PHF14 has been identified in various cancers and is known to be implicated in the pathogenesis of tumors. This study investigates the role and the underlying mechanisms of PHF14 in GBM (glioblastoma multiforme).

Methods

Tissue microarrays and public databases interrogation were used to explore the relationship between the expression of PHF14 and GBM. Three stable PHF14-silenced cell lines (U251, U87MG and A172) were constructed to assess the biological functions changes of GBM cells in vitro. In addition, tumorigenicity in vivo was also performed using U87MG cell line. To understand the mechanism of action of PHF14, RNA-Seq, qRT-PCR, Western blot, IC50 assay and subsequent pathway analysis were performed.

Results

Our results showed that the expression of PHF14 was upregulated in glioma, especially in GBM. Overexpression of PHF14 translated to poor prognosis in glioma patients. In vitro assays revealed that silencing expression of PHF14 in glioma cells inhibited migration, invasiveness and proliferation and promoted cell apoptosis. Animal assay further confirmed that over-expression of PHF14 was a dismal prognostic factor. Analysis based on RNA-Seq suggested a PHF14-dependent regulation of Wnt signaling networks, which was further validated by qRT-PCR, Western blot and IC50 analysis. In addition, the mRNA expression of several key markers of EMT (epithelial–mesenchymal transition) and angiogenesis was found to change upon PHF14 silencing.

Conclusions

Our data provide a new insight into the biological significance of PHF14 in glioma and its potential application in therapy and diagnosis.

Transcortical insular glioma resection: clinical outcome and predictors

OBJECTIVE

Insular lobe gliomas continue to challenge neurosurgeons due to their complex anatomical position. Transcortical and transsylvian corridors remain the primary approaches for reaching the insula, but the adoption of one technique over the other remains controversial. The authors analyzed the transcortical approach of resecting insular gliomas in the context of patient tumor location based on the Berger-Sinai classification, achievable extents of resection (EORs), overall survival (OS), and postsurgical neurological outcome.

METHODS

The authors studied 255 consecutive cases of insular gliomas that underwent transcortical tumor resection in their division. Tumor molecular pathology, location, EOR, postoperative neurological outcome for each insular zone, and the accompanying OS were incorporated into the analysis to determine the value of this surgical approach.

RESULTS

Lower-grade insular gliomas (LGGs) were more prevalent (63.14%). Regarding location, giant tumors (involving all insular zones) were most prevalent (58.82%) followed by zone I+IV (anterior) tumors (20.39%). In LGGs, tumor location was an independent predictor of survival (p = 0.003), with giant tumors demonstrating shortest patient survival (p = 0.003). Isocitrate dehydrogenase 1 (IDH1) mutation was more likely to be associated with giant tumors (p < 0.001) than focal tumors located in a regional zone. EOR correlated with survival in both LGG (p = 0.001) and higher-grade glioma (HGG) patients (p = 0.008). The highest EORs were achieved in anterior-zone LGGs (p = 0.024). In terms of developing postoperative neurological deficits, patients with giant tumors were more susceptible (p = 0.038). Postoperative transient neurological deficit was recorded in 12.79%, and permanent deficit in 15.70% of patients. Patients who developed either transient or permanent postsurgical neurological deficits exhibited poorer survival (p < 0.001).

CONCLUSIONS

The transcortical surgical approach can achieve maximal tumor resection in all insular zones. In addition, the incorporation of adjunct technologies such as multimodal brain imaging and mapping of cortical and subcortical eloquent brain regions into the transcortical approach favors postoperative neurological outcomes, and prolongs patient survival.

Functional near-infrared spectroscopy for intraoperative brain mapping

Functional near-infrared spectroscopy (fNIRS) is a relatively new seizure-free technique and its value for intraoperative brain mapping is unknown. We examine the feasibility of fNIRS for intraoperative functional brain mapping. A 1 × 1    cm 2 density fNIRS probe specially designed for intraoperative use was used to map brain function in adult patients undergoing awake brain surgery and performing motor and/or language tasks. The ability of fNIRS for functional mapping was compared with direct cortical stimulation (DCS) and regression was used to determine if mean blood pressure (MBP) and blood hemoglobin influenced fNIRS measurements. Eighteen patients underwent awake craniotomy and performed 19 language- and 17 motor-related tasks. fNIRS mapping was highly correlated with DCS for 10 language- and 7 motor-related tasks. fNIRS was able to detect functional language ( p < 0.001 ) and motor areas ( p = 0.002 ). Compared to DCS, fNIRS was less accurate in determining both functional language (at least 22.64%, p < 0.001 ) and motor areas (at least 32.74%, p < 0.001 ). Higher MBP and blood hemoglobin were associated with better fNIRS results ( p = 0.045 and 0.007, respectively). No seizures or other complications occurred during fNIRS measurement. fNIRS is a promising seizure-free technique for intraoperative brain mapping. The accuracy of current technology needs further development for clinical use.

Awake Transcortical Approach Resection of Dominant Posterior Cingulate Gyrus Glioma: 2-Dimensional Operative Video

Two techniques, the translongitudinal cerebral fissure and transfrontal cortical approach, can be employed to resect posterior cingulate gyrus tumors. We demonstrate the transcortical technique comprising of multimodal imaging guidance and awake brain mapping which enabled maximum safe resection of dominant cingulate gyrus glioma.  The patient, a 49-yr-old female, came to clinic after experiencing headache for a month. Initial magnetic resonance imaging (MRI) scans revealed a nonenhancing lesion of the left posterior cingulate gyrus. Three-dimensional magnetic resonance spectroscopy was used to analyze the choline/N-acetyl-aspartate index (CNI) which strongly suggested a low-grade glioma diagnosis.  In surgery, after creating a tailed bone window and dural opening, strip electrode was placed across the central sulcus for continuous motor evoked potential monitoring. Next, direct cortical stimulation was done to map functional cortical areas. The transcortical approach was chosen at this point because many veins hindered hemisphere retraction. Noneloquent cortical incisions were made and the tumor was carefully debunked with a cavitron ultrasonic surgical aspirator. The corpus callosum marked the deep end of dissection. Subcortical mapping combined with diffusion tensor imaging tractography-based navigation was performed to localize motor and language tracks. Intraoperative MRI evaluation confirmed a gross total resection. Pathological and molecular analysis revealed a World Health Organization Grade II IDH-wildtype Diffuse Astrocytoma diagnosis. Since the patient falls in high-risk group, she was also administered radiation and chemotherapy. Long-term cognitive evaluation follow-up of the patient showed she had good functional recovery with no obvious long-term deficits.  Informed patient consent was obtained.

The Analysis of Risk Factors and Survival Outcome for Chinese Patients with Epilepsy with High-Grade Glioma

OBJECTIVE

To evaluate the risk factors of tumor-related epilepsy (TRE) and the relationship between TRE and functional/survival outcomes in patients with high-grade glioma (HGG).

METHODS

The clinical data of 587 patients with HGG were retrospectively analyzed. A χ² test and logistic multiple-regression analysis were used to analyze factors associated with TRE. Logistic and Cox regression were used to analyze factors that may influence functional and survival outcomes.

RESULTS

Glioma location in temporal (odds ratio [OR], 0.439; P = 0.04) and parietal lobes (OR, 0.092; P = 0.02) were independent protective factors of preoperative epilepsy, compared with gliomas of frontal lobe. Preoperative epilepsy (OR, 9.290; P < 0.001) and dominant hemispheric location (OR, 2.616; P = 0.04) were independent risk factors of postoperative epilepsy. On univariate analysis, patients with preoperative epilepsy had longer progression-free survival (PFS) (P = 0.001) and overall survival (OS) (P < 0.001). Multivariate analysis further confirmed that preoperative epilepsy was an independent protective factor of OS (hazard ratio, 0.587; P = 0.008).

CONCLUSIONS

In patients with HGG, preoperative epilepsy is significantly associated with tumor involvement of the frontal lobe, whereas postoperative epilepsy is associated with preoperative epilepsy and dominant hemispheric location. Also, patients with HGG with preoperative epilepsy have better PFS and OS.

Perioperative Multimodal Evaluation and Surgical Tactics of Tumor-Related Epilepsy: 2-Dimensional Operative Video

Treatment of tumor-related epilepsy (TRE), especially for tumors near critical areas, requires surgeons to strike a balance between the epileptic benefit and functional outcome after surgery. Here, we present a case in which multimodal evaluation facilitated the achievement of such surgical balance. Informed patient consent was obtained. A 17-yr-old female presented with seizure attacks for 2 yr. Magnetic resonance imaging (MRI) revealed a right parietal mass lesion with hypointense signal on T1W imaging, hyperintense signal on T2W imaging, and homogeneous enhancement. Carbamazepine and valproate administration were unable to control the intermittent seizures. From the patient's history and imaging, the initial diagnosis was refractory TRE. Whether lesionectomy would achieve seizure freedom in this case was not certain. Therefore, dESI (dense array EEG source imaging) was used to localize the epileptic zone preoperatively; results showed that the epileptic zone was very close to the lesion in the primary motor cortex. Surgery was carried out under awake-anesthesia, with the aid of multimodal neuronavigation, intraoperative neurophysiological monitoring, and intraoperative MRI evaluation. A gross total lesion resection was achieved while preserving critical motor areas. Histopathology revealed ganglioglioma grade I diagnosis. No motor deficits following surgery were detected except slight increase of muscle tension in the right lower limb. At 6-mo follow-up, the patient was without any motor impairment or any other neurological deficits and completely seizure-free with the antiepileptic drug Carbamazepine 1200 mg/day.

Intraoperative awake brain mapping and multimodal image-guided resection of dominant side insular glioma

Resection of insular tumors in the dominant hemisphere poses a significant risk of postoperative motor and language deficits. The authors present a case in which intraoperative awake mapping and multi-modal imaging was used to help preserve function while resecting a dominant insular glioma. The patient, a 55-year-old man, came to the clinic after experiencing sudden onset of numbness in the right limbs for 4 months. Preoperative MRI revealed a nonenhancing lesion in the left insular lobe. Gross-total tumor resection was achieved through the transcortical approach, and the patient recovered without language or motor deficits. Informed patient consent was obtained. The video can be found here: https://youtu.be/gFky09ekmzw .

BRAF V600E, TERT, and IDH2 Mutations in Pleomorphic Xanthoastrocytoma: Observations from a Large Case-Series Study

BACKGROUND

Anaplastic pleomorphic xanthoastrocytoma (PXA) was added to grade III glial tumors as a distinct entity in the 2016 World Health Organization (WHO) classification of tumors of the central nervous system. We retrospectively reviewed and analyzed 55 pathologically confirmed PXA cases according to the newest WHO classification to better clarify the clinical, molecular, and prognostic features of this rare neoplasm.

METHODS

In total, 55 pathologically confirmed PXA cases according to the newest WHO classification were retrospectively reviewed and analyzed. After sequencing for BRAF, TERT, IDH1/2, and H3F3A, survival analysis was performed to determine the factors affecting survival.

RESULTS

The patients with BRAF V600E mutations were generally younger than those without it, although not statistically significant (27.9 ± 15.4 years and 37.1 ± 17.0 years, respectively, P = 0.054). TERT promoter mutation frequency in PXA was lower than in patients with anaplastic PXA although not statistically significant (4.4% and 28.6%, P = 0.083). One instance of PXA with IDH2 mutation, and no IDH1 and H3F3A mutations were found. In terms of prognosis, patients with anaplastic PXA had shorter overall survival and progression-free survival compared with patients with PXA. The subgroup with gross total resection had a longer median OS (not reached vs. 60.0 months, P = 0.0221) and PFS (not reached vs. 60.0 months, P = 0.0232) compared with patients with PXA with subtotal resection.

CONCLUSIONS

The identification of BRAF V600E, TERT, and IDH2 mutations in PXA expands our molecular understanding of PXA. Patients with PXA with gross total resection achieve good outcomes.

Reorganization of cerebro-cerebellar circuit in patients with left hemispheric gliomas involving language network: A combined structural and resting-state functional MRI study

The role of cerebellum and cerebro-cerebellar system in neural plasticity induced by cerebral gliomas involving language network has long been ignored. Moreover, whether or not the process of reorganization is different in glioma patients with different growth kinetics remains largely unknown. To address this issue, we utilized preoperative structural and resting-state functional MRI data of 78 patients with left cerebral gliomas involving language network areas, including 46 patients with low-grade glioma (LGG, WHO grade II), 32 with high-grade glioma (HGG, WHO grade III/IV), and 44 healthy controls. Spontaneous brain activity, resting-state functional connectivity and gray matter volume alterations of the cerebellum were examined. We found that both LGG and HGG patients exhibited bidirectional alteration of brain activity in language-related cerebellar areas. Brain activity in areas with increased alteration was significantly correlated with the language and MMSE scores. Structurally, LGG patients exhibited greater gray matter volume in regions with increased brain activity, suggesting a structure-function coupled alteration in cerebellum. Furthermore, we observed that cerebellar regions with decreased brain activity exhibited increased functional connectivity with contralesional cerebro-cerebellar system in LGG patients. Together, our findings provide empirical evidence for a vital role of cerebellum and cerebro-cerebellar circuit in neural plasticity following lesional damage to cerebral language network. Moreover, we highlight the possible different reorganizational mechanisms of brain functional connectivity underlying different levels of behavioral impairments in LGG and HGG patients.

Long-Term Functional and Oncologic Outcomes of Glioma Surgery with and without Intraoperative Neurophysiologic Monitoring: A Retrospective Cohort Study in a Single Center

OBJECTIVE

To evaluate long-term functional and survival outcomes of patients with glioma after intraoperative neurophysiologic monitoring (IONM) application.

METHODS

A total of 856 patients with glioma, who underwent tumor resection between October 2010 and March 2016, were included in this retrospective cohort study. All patients were stratified into IONM (439 patients) and non-IONM groups (417 patients). The primary outcome measured was overall survival (OS), and the secondary outcome measured was rate of late neurologic deficits. Analyses were performed using univariate tests and multivariate logistic regression and Cox proportional hazard model.

RESULTS

The 2 cohorts were well balanced with respect to baseline characteristics. Univariate survival analysis showed longer OS in the IONM group than that in the non-IONM group (P = 0.036), especially in patients with high-grade astrocytic tumor (P = 0.034). The IONM group showed a lower rate of neurologic deficits than did the non-IONM group. Multivariate analysis showed that IONM was a favorable factor of OS (odds ratio, 0.776; P = 0.046) and late neurologic function (odds ratio, 0.583; P = 0.039). Dominant hemispheric and eloquent location of glioma had no association with OS.

CONCLUSIONS

Application of IONM is beneficial to long-term functional and oncologic outcomes of patients with glioma.

An automated method for identifying an independent component analysis-based language-related resting-state network in brain tumor subjects for surgical planning

As a noninvasive and “task-free” technique, resting-state functional magnetic resonance imaging (rs-fMRI) has been gradually applied to pre-surgical functional mapping. Independent component analysis (ICA)-based mapping has shown advantage, as no a priori information is required. We developed an automated method for identifying language network in brain tumor subjects using ICA on rs-fMRI. In addition to standard processing strategies, we applied a discriminability-index-based component identification algorithm to identify language networks in three different groups. The results from the training group were validated in an independent group of healthy human subjects. For the testing group, ICA and seed-based correlation were separately computed and the detected language networks were assessed by intra-operative stimulation mapping to verify reliability of application in the clinical setting. Individualized language network mapping could be automatically achieved for all subjects from the two healthy groups except one (19/20, success rate = 95.0%). In the testing group (brain tumor patients), the sensitivity of the language mapping result was 60.9%, which increased to 87.0% (superior to that of conventional seed-based correlation [47.8%]) after extending to a radius of 1 cm. We established an automatic and practical component identification method for rs-fMRI-based pre-surgical mapping and successfully applied it to brain tumor patients.