Using Machine Learning to Evaluate Large-scale Brain Networks Patients with Brain Tumors: Traditional and non-Traditional eloquent areas

Background

Large-scale brain networks and higher cognitive functions are frequently altered in neuro-oncology patients, but comprehensive non-invasive brain mapping is difficult to achieve in the clinical setting. The objective of our study is to evaluate traditional and non-traditional eloquent areas in brain tumor patients using a machine-learning platform.

Methods

We retrospectively included patients who underwent surgery for brain tumor resection at our Institution. Preoperative MRI with T1-weighted and DTI sequences were uploaded into the Quicktome platform. We categorized the integrity of nine large-scale brain networks: language, sensorimotor, visual, ventral attention, central executive, default mode, dorsal attention, salience and limbic. Network integrity was correlated with preoperative clinical data.

Results

One-hundred patients were included in the study. The most affected network was the central executive network (49%), followed by the default mode network (43%) and dorsal attention network (32%). Patients with preoperative deficits showed a significantly higher number of altered networks before the surgery (3.42 vs 2.19, P < .001), compared to patients without deficits. Furthermore, we found that patients without neurologic deficits had an average 2.19 networks affected and 1.51 networks at-risk, with most of them being related to non-traditional eloquent areas (P < .001).

Conclusion

Our results show that large-scale brain networks are frequently affected in patients with brain tumors, even when presenting without evident neurologic deficits. In our study, the most commonly affected brain networks were related to non-traditional eloquent areas. Integrating non-invasive brain mapping machine-learning techniques into the clinical setting may help elucidate how to preserve higher-order cognitive functions associated with those networks.

Safety of the utilization of telemedicine for brain tumor neurosurgery follow-up

Background

There is a need to evaluate the outcomes of patients who underwent brain tumor surgery with subsequent telemedicine or in-person follow-up during the COVID-19 pandemic.

Methods

We retrospectively included all patients who underwent surgery for brain tumor resection by a single neurosurgeon at our Institution from the beginning of the COVID-19 pandemic restrictions (March 2020) to August 2021. Outcomes were assessed by stratifying the patients using their preference for follow-up method (telemedicine or in-person).

Results

Three-hundred and eighteen (318) brain tumor patients who were included. The follow-up method of choice was telemedicine (TM) in 185 patients (58.17%), and in-person (IP) consults in 133 patients. We found that patients followed by TM lived significantly farther, with a median of 36.34 miles, compared to a median of 22.23 miles in the IP cohort (P = .0025). We found no statistical difference between the TM and the IP group, when comparing visits to the emergency department (ED) within 30 days after surgery (7.3% vs 6.01%, P = .72). Readmission rates, wound infections, and 30-day mortality were similar in both cohorts. These findings were also consistent after matching cohorts using a propensity score. The percentage of telemedicine follow-up consults was higher in the first semester (73.17%) of the COVID-19 pandemic, compared to the second (46.21%), and third semesters (47.86%).

Conclusions

Telehealth follow-up alternatives may be safely offered to patients after brain tumor surgery, thereby reducing patient burden in those with longer distances to the hospital or special situations as the COVID-19 pandemic.

Traumatic brain injury and subsequent brain tumor development: a systematic review of the literature

The role of prior head trauma in stimulating brain tumor development has been previously described in the literature but continues to be debated. The goal of this study was to conduct a systematic review interrogating the contemporary literature to delineate any possible relationship between traumatic brain injury and brain tumor development. A systematic review exploring development of post-TBI brain tumor was conducted by searching electronic databases. Abstracts from articles were read and selected for full-text review according to criteria previously established in the scientific literature. Relevant full-text articles were divided into case reports and single-arm studies and epidemiological studies. Of 1070 resultant articles, 18 case reports and single-arm studies (level of evidence of IV and V) with 45 patients were included. The most common cause of TBI was traffic accidents. The average period between TBI and subsequent tumor diagnosis was 12.8 years. Meningiomas represented the largest share of tumors, followed by gliomas. Most post-TBI brain tumors developed in the frontal and temporal lobes. Fifteen epidemiological studies were also interrogated from a variety of countries (level of evidence of III). Case-control studies were more common than cohort studies. There were 9 of 15 studies proposed a possible relationship between history of head trauma and development of brain tumor. The relationship between head trauma and neoplastic growth continues to be heavily debated. There are certainly case reports and epidemiological studies in the literature that suggest a correlational relationship between the two. However, there is no concrete evidence of a causal relationship between TBI and brain tumors. More research is needed to definitively delineate the extent of any such relationship.

Systematic Review of Epigenetic Therapies for Treatment of IDH-mutant Glioma

BACKGROUND

Isocitrate dehydrogenase (IDH) mutations are present in 70% of World Health Organization grade II and III gliomas. IDH mutation induces accumulation of the oncometabolite 2-hydroxyglutarate. Therefore, therapies targeting reversal of epigenetic dysregulation in gliomas have been suggested. However, the utility of epigenetic treatments in gliomas remains unclear. Here, we present the first clinical systematic review of epigenetic therapies in treatment of IDH-mutant gliomas and highlight their safety and efficacy.

METHODS

We conducted a systematic search of electronic databases from 2000 to January 2021 following PRISMA guidelines. Articles were screened to include clinical usage of epigenetic therapies in case reports, prospective case series, or clinical trials. Primary and secondary outcomes included safety/tolerability of epigenetic therapies and progression-free survival/overall survival, respectively.

RESULTS

A total of 133 patients across 8 clinical studies were included in our analysis. IDH inhibitors appear to have the best safety profile, with an overall grade 3/grade 4 adverse event rate of 9%. Response rates to IDH-mutant inhibitors were highest in nonenhancing gliomas (stable disease achieved in 55% of patients). In contrast, histone deacetylase inhibitors demonstrate a lower safety profile with single-study adverse events as high as 28%.

CONCLUSION

IDH inhibitors appear promising given their benign toxicity profile and ease of monitoring. Histone deacetylase inhibitors appear to have a narrow therapeutic index, as lower concentrations do not appear effective, while increased doses can produce severe immunosuppressive effects. Preliminary data suggest that epigenetic therapies are generally well tolerated and may control disease in certain patient groups, such as those with nonenhancing lesions.

Same-day discharge after brain tumor resection: a prospective pilot study

Purpose

Outpatient brain surgery has many advantages for the psychological and physical wellbeing of patients, as well as reduced costs to the health care system. Compared with inpatient admissions, same day discharges reduce patient exposure to nosocomial infection, thromboembolic complications, and medical error. We aim to establish a prospectively collected quality outcomes database to examine the outcomes of patients that undergo brain tumor resection and are discharged home the same day as surgery.

Methods

We have established a prospectively collected quality outcomes database to examine the outcomes of all patients that underwent brain tumor resection by a single neurosurgeon (R.J.K) at our institution from August 2020 to August 2021 and were discharged home the same day as surgery.

Results

Over the one-year period this study was conducted, 37 of 334 patients met inclusion criteria for the outpatient protocol. Thirty-two patients were discharged on the same day as surgery. Five patients (14%) were considered eligible for outpatient surgery but were ultimately admitted to the hospital postoperatively and were discharged after an overnight observation. No postoperative complications were noted at two-week postoperative follow-up.

Conclusion

In select patients undergoing brain tumor surgery, same day discharge should be considered. Establishing a multidisciplinary team of physicians, nurses, radiologists, and physical therapists is critical to achieving this aim. Physicians should have a low threshold to admit a patient with concerning exam findings, complications, or complicated past medical history. Once discharged, open communication with the patient and their family is critical to detect complications that should trigger rehospitalization and intervention.

Transcortical resection of a giant bilobed falcine meningioma

INTRODUCTION

Falcine meningiomas present significant surgical challenges because they often involve the falx bilaterally, are concealed by a significant amount of normal brain parenchyma and are frequently deep in location and in close proximity to the anterior cerebral arteries. Many prefer the interhemispheric approach for these lesions, but this operative corridor is not without risk as venous infarctions and cortical injury can occur.

CLINICAL PRESENTATION

We present an alternative technique utilizing a transcortical approach to resect a giant, bilobed falcine meningioma in a 68-year-old female who presented with progressive abulia, urinary incontinence, and bilateral lower extremity weakness over 2 years. A unilateral right frontal craniotomy and a corticectomy through the right superior frontal gyrus was used to safely resect the entire tumor. The patient tolerated the procedure well and was discharged home without issue. Pathology demonstrated that the lesion was an atypical meningioma and she subsequently received adjuvant fractionated radiotherapy. At 2-year follow-up, she has no neurologic deficits, never developed any postoperative seizures and has not had any evidence of tumor recurrence.

CONCLUSION

The transcortical approach can be used as a safe alternative for resecting falcine meningiomas without adding significant undue risk to the patient.

Factors associated with the use of salvage whole brain radiation therapy versus salvage stereotactic radiosurgery after initial stereotactic radiosurgery for brain metastases

Objectives

Patients undergoing stereotactic radiosurgery (SRS) for brain metastases require additional radiation for relapse. Our objective is to determine the factors associated with salvage SRS versus whole brain radiation therapy (WBRT) for salvage of first intracranial failure (ICF) after upfront SRS.

Method

We identified a cohort of 110 patients with brain metastases treated with SRS in the definitive or postoperative setting followed by subsequent salvage WBRT or SRS at least one month after initial SRS. Clinical and demographic characteristics were retrospectively recorded.

Results

78 Patients received SRS and 32 patients received WBRT at the time of first ICF. On multivariate analysis (MVA) factors associated with decreased use of salvage SRS were male gender (p=0.044) and local progression (p<0.001).

Conclusions

Local progression and male gender were the strongest factors associated with selection of salvage WBRT. Possible etiologies of this difference could be provider or patient driven, but warrant further exploration.

A Multiparametric Pharmacogenomic Strategy for Drug Repositioning predicts Therapeutic Efficacy for Glioblastoma Cell Lines

Background

Poor prognosis of glioblastoma patients and the extensive heterogeneity of glioblastoma at both the molecular and cellular level necessitates developing novel individualized treatment modalities via genomics-driven approaches.

Methods

This study leverages numerous pharmacogenomic and tissue databases to examine drug repositioning for glioblastoma. RNAseq of glioblastoma tumor samples from The Cancer Genome Atlas (TCGA, n=117) were compared to “normal” frontal lobe samples from Genotype-Tissue Expression Portal (GTEX, n=120) to find differentially expressed genes (DEGs). Using compound-gene expression data and drug activity data from the Library of Integrated Network-Based Cellular Signatures (LINCS, n=66,512 compounds) CCLE (71 glioma cell lines), and Chemical European Molecular Biology Laboratory (ChEMBL) platforms, we employed a summarized reversal gene expression metric (sRGES) to “reverse” the resultant disease signature for GBM and its subtypes. A multi-parametric strategy was employed to stratify compounds capable of blood brain barrier penetrance with a favorable pharmacokinetic profile (CNS-MPO).

Results

Significant correlations were identified between sRGES and drug efficacy in GBM cell lines in both ChEMBL(r=0.37,p&lt;.001) and Cancer Therapeutic Response Portal (CTRP) databases (r=0.35, p&lt;0.001). Our multiparametric algorithm identified two classes of drugs with highest sRGES and CNS-MPO: HDAC inhibitors (vorinostat and entinostat) and topoisomerase inhibitors suitable for drug repurposing.

Conclusions

Our studies suggest that reversal of glioblastoma disease signature correlates with drug potency for various GBM subtypes. This multiparametric approach may set the foundation for an early-phase personalized -omics clinical trial for glioblastoma by effectively identifying drugs that are capable of reversing the disease signature and have favorable pharmacokinetic and safety profiles.

Supralesional Ablation Volumes Are Feasible in the Posterior Fossa and May Provide Enhanced Symptomatic Relief

BACKGROUND

Laser interstitial thermal therapy (LITT) for posterior fossa lesions remains rare as the small size of the infratentorial compartment, proximity to the brainstem, and thickness/angulation of the occipital bone creates barriers to procedural success. Furthermore, evaluation of the effect of ablation volume on outcomes is limited.

OBJECTIVE

To analyze our institutional experience with LITT in the posterior fossa stratifying perioperative and long-term outcomes by ablation volumes.

METHODS

Seventeen patients with posterior fossa lesions treated with LITT from 2013 to 2020 were identified. Local progression-free survival (PFS), overall survival, steroid dependence, and edema reduction were evaluated with Kaplan-Meier analysis grouped by ablation volume. Preoperative, postoperative, and last known Karnofsky Performance Status (KPS) were compared using a matched paired t test.

RESULTS

No differences in pathology, preoperative KPS, or preoperative lesion volume were found between patients with total (100%-200% increase in pre-LITT lesion volume) versus radical (>200% increase in pre-LITT lesion volume) ablations. Patients who underwent radical ablation had a higher postoperative KPS (93 vs 82, P = .02) and higher KPS (94 vs 87, P = .04) and greater reduction in perilesional edema at last follow-up (P = .01). Median follow-up was 80.8 wk.

CONCLUSION

Despite obvious anatomical challenges, our results demonstrate that radical ablations are both feasible and safe in the posterior fossa. Furthermore, radical ablations may lead to greater decreases in perilesional edema and improved functional status both immediately after surgery and at last follow-up. Thus, LITT should be considered for patients with otherwise unresectable or radioresistant posterior fossa lesions.

Using smartphone-based accelerometers to gauge postoperative outcomes in patients with NPH: Implications for ambulatory monitoring

Background

The surgical treatment of normal pressure hydrocephalus (NPH) with shunting remains controversial due to the difficulty in distinguishing such pathology from other neurological conditions that can present similarly. Thus, patients with suspected NPH should be carefully selected for surgical intervention. Historically, clinical improvement has been measured by the use of functional grades, alleviation of symptoms, and/or patient/family-member reported surveys. Such outcome analysis can be subjective, and there is difficulty in quantifying cognition. Thus, a push for a more quantifiable and objective investigation is warranted, especially for patients with idiopathic NPH (INPH), for which the final diagnosis is confirmed with postoperative clinical improvement. We aimed to use Apple Health (Apple Inc., Cupertino, CA) data to approximate physical activity levels before and after shunt placement for NPH as an objective outcome measurement. The patients were contacted and verbally consented to export Apple Health activity data. The patient's physical activity data were then analyzed. A chart review from the patient's EMR was performed to understand and better correlate recovery.

Case Description

Our first patient had short-term improvements in activity levels when compared to his preoperative activity. The patient's activity level subsequently decreased at 6 months and onward. This decline was simultaneous to new-onset lumbar pain. Our second patient experienced sustained improvements in activity levels for 12 months after his operation. His mobility data were in congruence with his subjectively reported improvement in clinical symptoms. He subsequently experienced a late-decline that began at 48-months. His late deterioration was likely confounded by exogenous factors such as further neurodegenerative diseases coupled with old age.

Conclusion

The use of objective activity data offers a number of key benefits in the analysis of shunted patients with NPH/INPH. In this distinctive patient population, detailed functional outcome analysis is imperative because the long-term prognosis can be affected by comorbid factors or life expectancy. The benefits from using smartphone-based accelerometers for objective outcome metrics are abundant and such an application can serve as a clinical aid to better optimize surgical and recovery care.

Augmented reality head-mounted display-based incision planning in cranial neurosurgery: a prospective pilot study

OBJECTIVE

Monitor and wand-based neuronavigation stations (MWBNSs) for frameless intraoperative neuronavigation are routinely used in cranial neurosurgery. However, they are temporally and spatially cumbersome; the OR must be arranged around the MWBNS, at least one hand must be used to manipulate the MWBNS wand (interrupting a bimanual surgical technique), and the surgical workflow is interrupted as the surgeon stops to "check the navigation" on a remote monitor. Thus, there is need for continuous, real-time, hands-free, neuronavigation solutions. Augmented reality (AR) is poised to streamline these issues. The authors present the first reported prospective pilot study investigating the feasibility of using the OpenSight application with an AR head-mounted display to map out the borders of tumors in patients undergoing elective craniotomy for tumor resection, and to compare the degree of correspondence with MWBNS tracing.

METHODS

Eleven consecutive patients undergoing elective craniotomy for brain tumor resection were prospectively identified and underwent circumferential tumor border tracing at the time of incision planning by a surgeon wearing HoloLens AR glasses running the commercially available OpenSight application registered to the patient and preoperative MRI. Then, the same patient underwent circumferential tumor border tracing using the StealthStation S8 MWBNS. Postoperatively, both tumor border tracings were compared by two blinded board-certified neurosurgeons and rated as having an excellent, adequate, or poor correspondence degree based on a subjective sense of the overlap. Objective overlap area measurements were also determined.

RESULTS

Eleven patients undergoing craniotomy were included in the study. Five patient procedures were rated as having an excellent correspondence degree, 5 had an adequate correspondence degree, and 1 had poor correspondence. Both raters agreed on the rating in all cases. AR tracing was possible in all cases.

CONCLUSIONS

In this small pilot study, the authors found that AR was implementable in the workflow of a neurosurgery OR, and was a feasible method of preoperative tumor border identification for incision planning. Future studies are needed to identify strategies to improve and optimize AR accuracy.

When "Peripheral" Becomes "Central": Primary and Secondary Malignant Intracerebral Nerve Sheath Tumor: A Case Report and a Systematic Review

BACKGROUND

The intracerebral occurrence of malignant peripheral nerve sheath tumors (MPNSTs) is exceedingly rare, and despite aggressive treatments, local recurrence and poor prognosis are very frequent. Like other brain tumors, these tumors could be primary or secondary, making the term "peripheral" an imprecise term for a primary brain tumor.

OBJECTIVE

To analyze the reported cases of primary and secondary cerebral MPSNTs in terms of diagnosis, treatment, and overall survival. Additionally, we present a case of malignant intracerebral nerve sheath tumor (MINST) treated with radical surgery and radiotherapy.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, one database (PubMed) and crossed references were queried for MPNST with brain metastasis and primary MINSTs from 1971 to 2020. Data regarding demographic features, primary tumor site, risk factors, brain location of the lesion, treatment applied, and overall survival were extracted.

RESULTS

A total of 55 patients were selected (including the reported case): 29 patients were secondary brain MPNST and 26 patients were primary MINST. The mean age was 41.8 ± 22 and 31.2 ± 23 yr, respectively. All brain metastases of MPNST (100%) had a primary tumor elsewhere in the body at the time of diagnosis. The overall survival was significantly shorter in patients with a secondary brain MPNST compared to MINST (P = .002).

CONCLUSION

We present a comprehensive analysis of every reported primary and secondary intracerebral MPNST. The prognosis in terms of survival is worst in the last one despite aggressive treatment. The lack of a primary MPNST in screening tests is sufficient to confirm a MINST at time of diagnosis.

Ventriculostomy supply cart decreases time-to-external ventricular drain placement in the emergency department

Background:

Minimizing time-to-external ventricular drain (EVD) placement in the emergency department (ED) is critical. We sought to understand factors affecting time-to-EVD placement through a quality improvement initiative.

Methods:

The use of process mapping, root cause analyses, and interviews with staff revealed decentralized supply storage as a major contributor to delays in EVD placement. We developed an EVD “crash cart” as a potential solution to this problem. Time-to-EVD placement was tracked prospectively using time stamps in the electronic medical record (EMR); precart control patients were reviewed retrospectively.

Results:

The final cohorts consisted of 33 precart and 18 postcart cases. The mean time-to-EVD in the precart group was 99.09 min compared to 71.88 min in the postcart group (two-tailed t-test, P = 0.023). Median time-to-EVD was 92 min in the precart group compared to 64 min in the postcart group (rank sum test, P = 0.0165). Postcart patients trended toward improved outcomes with lower modified Rankin score scores at 1 year, but this did not reach statistical significance (two-tailed t-test, P = 0.177).

Conclusion:

An EVD “crash cart” is a simple intervention that can significantly reduce time-to-EVD placement and may improve outcomes in patients requiring an EVD.

Robotic guidance platform for laser interstitial thermal ablation and stereotactic needle biopsies: a single center experience

While laser ablation has become an increasingly important tool in the neurosurgical oncologist's armamentarium, deep seated lesions, and those located near critical structures require utmost accuracy during stereotactic laser catheter placement. Robotic devices have evolved significantly over the past two decades becoming an accurate and safe tool for stereotactic neurosurgery. Here, we present our single center experience with the MedTech ROSA ONE Brain robot for robotic guidance in laser interstitial thermal therapy (LITT) and stereotactic biopsies. We retrospectively analyzed the first 70 consecutive patients treated with ROSA device at a single academic medical center. Forty-three patients received needle biopsy immediately followed by LITT with the catheter placed with robotic guidance and 27 received stereotactic needle biopsy alone. All the procedures were performed frameless with skull bone fiducials for registration. We report data regarding intraoperative details, mortality and morbidity, diagnostic yield and lesion characteristics on MRI. Also, we describe the surgical workflow for both procedures. The mean age was 60.3 ± 15 years. The diagnostic yield was positive in 98.5% (n = 69). Sixty-three biopsies (90%) were supratentorial and seven (10%) were infratentorial. Gliomas represented 54.3% of the patients (n = 38). There were two postoperative deaths (2.8%). No permanent morbidity related to surgery were observed. We did not find intraoperative technical problems with the device. There was no need to reposition the needle after the initial placement. Stereotactic robotic guided placement of laser ablation catheters and biopsy needles is safe, accurate, and can be implemented into a neurosurgical workflow.