Results from a first-in-human phase I safety trial to evaluate the use of a vascularized pericranial/temporoparietal fascial flap to line the resection cavity following resection of newly diagnosed glioblastoma

PURPOSE

The efficacy of systemic therapies for glioblastoma (GBM) remains limited due to the constraints of systemic toxicity and blood-brain barrier (BBB) permeability. Temporoparietal fascial flaps (TPFFs) and vascularized peri cranial flaps (PCF) are not restricted by the blood-brain barrier (BBB), as they derive their vascular supply from branches of the external carotid artery. Transposition of a vascularized TPFF or PCF along a GBM resection cavity may bring autologous tissue not restricted by the BBB in close vicinity to the tumor bed microenvironment, permit ingrowth of vascular channels fed by the external circulation, and offer a mechanism of bypassing the BBB. In addition, circulating immune cells in the vascularized flap may have better access to tumor-associated antigens (TAA) within the tumor microenvironment. We conducted a first-in-human Phase I trial assessing the safety of lining the resection cavity with autologous TPFF/PCF of newly diagnosed patients with GBM.

METHODS

12 patients underwent safe, maximal surgical resection of newly diagnosed GBMs, followed by lining of the resection cavity with a pedicled, autologous TPFF or PCF. Safety was assessed by monitoring adverse events. Secondary analysis of efficacy was examined as the proportion of patients experiencing progression-free disease (PFS) as indicated by response assessment in neuro-oncology (RANO) criteria and overall survival (OS). The study was powered to determine whether a Phase II study was warranted based on these early results. For this analysis, subjects who were alive and had not progressed as of the date of the last follow-up were considered censored and all living patients who were alive as of the date of last follow-up were considered censored for overall survival. For simplicity, we assumed that a 70% PFS rate at 6 months would be considered an encouraging response and would make an argument for further investigation of the procedure.

RESULTS

Median age of included patients was 57 years (range 46-69 years). All patients were Isocitrate dehydrogenase (IDH) wildtype. Average tumor volume was 56.6 cm3 (range 14-145 cm3). Resection was qualified as gross total resection (GTR) of all of the enhancing diseases in all patients. Grade III or above adverse events were encountered in 3 patients. No Grade IV or V serious adverse events occurred in the immediate post-operative period including seizure, infection, stroke, or tumor growing along the flap. Disease progression at the site of the original tumor was identified in only 4 (33%) patients (median 23 months, range 8-25 months), 3 of whom underwent re-operation. Histopathological analyses of those implanted flaps and tumor bed biopsy at repeat surgery demonstrated robust immune infiltrates within the transplanted flap. Importantly, no patient demonstrated evidence of tumor infiltration into the implanted flap. At the time of this manuscript preparation, only 4/12 (33%) of patients have died. Based on the statistical considerations above and including all 12 patients 10/12 (83.3%) had 6-month PFS. The median PFS was 9.10 months, and the OS was 17.6 months. 4/12 (33%) of patients have been alive for more than two years and our longest surviving patient currently is alive at 60 months.

CONCLUSIONS

This pilot study suggests that insertion of pedicled autologous TPFF/PCF along a GBM resection cavity is safe and feasible. Based on the encouraging response rate in 6-month PFS and OS, larger phase II studies are warranted to assess and reproduce safety, feasibility, and efficacy. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION FOR PROSPECTIVELY REGISTERED TRIALS: ClinicalTrials.gov ID NCT03630289, dated: 08/02/2018.

Autologous cell immunotherapy (IGV-001) with IGF-1R antisense oligonucleotide in newly diagnosed glioblastoma patients

Standard-of-care first-line therapy for patients with newly diagnosed glioblastoma (ndGBM) is maximal safe surgical resection, then concurrent radiotherapy and temozolomide, followed by maintenance temozolomide. IGV-001, the first product of the Goldspire™ platform, is a first-in-class autologous immunotherapeutic product that combines personalized whole tumor-derived cells with an antisense oligonucleotide (IMV-001) in implantable biodiffusion chambers, with the intent to induce a tumor-specific immune response in patients with ndGBM. Here, we describe the design and rationale of a randomized, double-blind, phase IIb trial evaluating IGV-001 compared with placebo, both followed by standard-of-care treatment in patients with ndGBM. The primary end point is progression-free survival, and key secondary end points include overall survival and safety.

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.

An algorithm for the treatment of concurrent pituitary adenoma and cavernous sinus aneurysm: A systematic review & case report

BACKGROUND

Rarely, Pituitary adenomas (PA) can co-occur with intrasellar or intracavernous aneurysms. There is currently no clear guidance for the management of this dual pathology. We attempt to provide an algorithm to help guide clinical decision making for treatment of PAs co-occurring with adjacent cerebral aneurysms.

METHODS

A comprehensive literature search was conducted following PRISMA guidelines using various databases. Search terms included "(Pituitary Adenoma OR Prolactinoma OR Macroadenoma OR Adenoma) AND (ICA OR Internal Carotid Artery OR paracliniod OR clinoid) Aneurysm AND (Intra-cavernous OR intracavernous OR intrasellar OR Cavernous)."

RESULTS

A total of 24 studies with 24 patients were included. Twelve (50%) patients experienced visual symptoms. Ten patients (42%) had an aneurysm embedded within the adenoma. Fourteen patients (58%) had an aneurysm adjacent to the adenoma. Embedded aneurysms were significantly associated with rupture events.

CONCLUSION

Vision loss is the most pressing determinant of treatment. In the absence of visual symptoms, the aneurysm should be treated first by coil embolization. If not amenable to coiling, place flow diverting stent followed by six months of anticoagulation and antiplatelet therapy. If visual loss is apparent, the adenoma-aneurysm spatial relationship becomes critical. In cases of an adjacent aneurysm, the adenoma should be removed transsphenoidally with extreme care and aneurysm rupture protocols in place. If the aneurysm is embedded within the adenoma, then a BTO is favored with permanent ICA occlusion followed by transsphenoidal resection if adequate collateral supply is demonstrated. If there is inadequate collateral supply, then an open-approach for amenable aneurysms with transcranial adenoma debulking should be performed.

First in-human intrathecal delivery of bevacizumab for leptomeningeal spread from recurrent glioblastoma: rationale for a dose escalation trial

PURPOSE

To outline the dose rationale for the first in-human intrathecal delivery of bevacizumab for LMS of GBM.

METHODS

A 19-year-old female patient presented to Lenox Hill Hospital following thalamic GBM recurrence. She subsequently underwent two infusions of intra-arterial BEV (NCT01269853) and experienced a period of relative disease stability until progression in 2022. One month later, MRI disclosed diffuse enhancement representative of LMS of GBM. The patient subsequently underwent five cycles of IT BEV in mid-2022 (IND 162119). Doses of 25 mg, 37.5 mg, 50 mg, 50 mg, and 37.8 mg were delivered at two-week intervals between doses 1-4. The final 37.8 mg dose was given one day following her fourth dose, given that the patient was to be discharged, traveled several hours to our center, and was tolerating therapy well. Dosage was decreased due to the short interval between the final two treatments. Shortly after IT BEV completion, she received a third dose of IA BEV.

RESULTS

Our patient did not show any signs of serious adverse effects or dose limiting toxicities following any of the treatments. It is difficult to determine PFS due to the rapid progression associated with LMS of GBM and rapid timeframe of treatment.

CONCLUSION

LMS continues to be a devastating progression in many types of cancer, including GBM, and novel ways to deliver therapeutics may offer patients symptomatic and therapeutic benefits.

Hippocampal avoidance in whole brain radiotherapy and prophylactic cranial irradiation: a systematic review and meta-analysis

PURPOSE

We systematically reviewed the current landscape of hippocampal-avoidance radiotherapy, focusing specifically on rates of hippocampal tumor recurrence and changes in neurocognitive function.

METHODS

PubMed was queried for studies involving hippocampal-avoidance radiation therapy and results were screened using PRISMA guidelines. Results were analyzed for median overall survival, progression-free survival, hippocampal relapse rates, and neurocognitive function testing.

RESULTS

Of 3709 search results, 19 articles were included and a total of 1611 patients analyzed. Of these studies, 7 were randomized controlled trials, 4 prospective cohort studies, and 8 retrospective cohort studies. All studies evaluated hippocampal-avoidance whole brain radiation treatment (WBRT) and/or prophylactic cranial irradiation (PCI) in patients with brain metastases. Hippocampal relapse rates were low (overall effect size = 0.04; 95% confidence interval [0.03, 0.05]) and there was no significant difference in risk of relapse between the five studies that compared HA-WBRT/HA-PCI and WBRT/PCI groups (risk difference = 0.01; 95% confidence interval [- 0.02, 0.03]; p = 0.63). 11 out of 19 studies included neurocognitive function testing. Significant differences were reported in overall cognitive function and memory and verbal learning 3-24 months post-RT. Differences in executive function were reported by one study, Brown et al., at 4 months. No studies reported differences in verbal fluency, visual learning, concentration, processing speed, and psychomotor speed at any timepoint.

CONCLUSION

Current studies in HA-WBRT/HA-PCI showed low hippocampal relapse or metastasis rates. Significant differences in neurocognitive testing were most prominent in overall cognitive function, memory, and verbal learning. Studies were hampered by loss to follow-up.

Improvement in visual outcomes of patients with base of skull meningioma as a result of evolution in the treatment techniques in the last three decades: a systematic review

PURPOSE

We systematically reviewed visual outcomes over the last three decades in patients undergoing treatment for base of skull (BOS) meningiomas and provide recommendations to preserve vision.

METHODS

In accordance with the PRISMA guidelines for systematic reviews, a search was conducted from 6/1/2022-9/1/2022 using PubMed and Web of Science. Inclusion criteria included (1) patients treated for BOS meningiomas (2) treatment modality specified (3) specifics of surgical techniques and/or dose/fractions of radiotherapy (4) individual patient outcomes of treatment. Each study was assessed for bias based on study design and heterogeneity of results.

RESULTS

A total of 50 studies were included (N = 2911). When comparing improved vision versus unchanged or worsened vision, studies investigating surgery alone published from 2006 and onward had significantly better visual outcomes compared to pre-2006 studies (p = 0.02). When comparing improved vision versus unchanged or worsened vision, studies investigating combined therapy with surgery and radiation published from 2008 and onward had significantly better visual outcomes compared to pre-2008 studies (p < 0.01). Combined modality therapy was less likely to worsen vision compared to either surgery or radiation monotherapy (p < 0.01). However, surgery and radiation monotherapy were more likely to actually improve outcomes compared to combination therapy (p < 0.01).

CONCLUSION

For over a decade we have observed improvement in visual outcomes in patients managed for meningioma of BOS, likely attributing the innovation in microsurgical and more targeted and conformal radiation techniques. Combination therapy may be the safest option for preventing worsening of vision, but the highest rates of improving visual function are achieved through monotherapy when indicated.

Cesium-131 brachytherapy for the treatment of brain metastases: Current status and future perspectives

Adjuvant radiotherapy is often necessary following surgical resection of brain metastases to improve local tumor control and survival. Brachytherapy using cesium-131 offers a novel method for loco-regional radiotherapy. We reviewed the current literature reporting the use of cesium-131 brachytherapy for the treatment of brain metastases. Published studies and ongoing trials were reviewed to identify treatment protocols and clinical outcomes of cesium-131 brachytherapy for brain metastases. Cesium-131 brachytherapy was further compared to current outcomes for iodine-125 brachytherapy and stereotactic radiosurgery. Intraoperative brachytherapy allows patients to receive two treatment modalities in one setting while minimizing tumor cell repopulation. After initial interest, the use of iodine-125 brachytherapy has declined due to unfavorable rates of radiation necrosis without survival improvement. Recent data on intracavitary cesium-131 brachytherapy in brain metastases have demonstrated improved locoregional tumor control with low risks of radiation necrosis, with associated improvements in patients compliance and satisfaction. Cesium-131 isotope has a short half-life, delivers 90% of its dose within a month, shortens the time to initiation of systemic therapy compared to iodine-125 or external radiotherapy, and has an excellent radiation safety profile. Further analyses have demonstrated superior cost-effectiveness and quality-of-life improvement ratios of cesium-131 brachytherapy than adjuvant stereotactic radiosurgery. Cesium-131 brachytherapy is a safe and effective post-surgical treatment option for brain metastases with associated clinical and cost-effectiveness benefits in appropriately selected patients.

Evolution of flash visual evoked potentials to monitor visual pathway integrity during tumor resection: illustrative cases and literature review

Flash visual evoked potentials (fVEPs) provide a means to interrogate visual system functioning intraoperatively during tumor resection in which the optic pathway is at risk for injury. Due to technical limitations, fVEPs have remained underutilized in the armamentarium of intraoperative neurophysiological monitoring (IONM) techniques. Here we review the evolution of fVEPs as an IONM technique with emphasis on the enabling technological and intraoperative improvements. A combined approach with electroretinography (ERG) has enhanced feasibility of fVEP neuromonitoring as a practical application to increase safety and reduce error during tumor resection near the prechiasmal optic pathway. The major advance has been towards differentiating true cases of damage from false findings. We use two illustrative neurosurgical cases in which fVEPs were monitored with and without ERG to discuss limitations and demonstrate how ERG data can clarify false-positive findings in the operating room. Standardization measures have focused on uniformity of photostimulation parameters for fVEP recordings between neurosurgical groups.

Short and long-term prognostic value of intraoperative motor evoked potentials in brain tumor patients: a case series of 121 brain tumor patients

PURPOSE

Iatrogenic neurologic deficits adversely affect patient outcomes following brain tumor resection. Motor evoked potential (MEP) monitoring allows surgeons to assess the integrity of motor-eloquent areas in real-time during tumor resection to lessen the risk of iatrogenic insult. We retrospectively associate intraoperative transcranial and direct cortical MEPs (TC-MEPs, DC-MEPs) to early and late post-operative motor function to prognosticate short- and long-term motor recovery in brain tumor patients undergoing surgical resection in peri-eloquent regions.

METHODS

We reviewed 121 brain tumor patients undergoing craniotomies with DC-MEP and/or TC-MEP monitoring. Motor function scores were recorded at multiple time-points up to 1 year postoperatively. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated at each time point.

RESULTS

The sensitivity, specificity, PPV, and NPV of TC-MEP in the immediate postoperative period was 17.5%, 100%, 100%, and 69.4%, respectively. For DC-MEP monitoring, the respective values were 25.0%, 100%, 100%, and 68.8%. By discharge, sensitivity had increased for both TC-MEP and DC MEPs to 43.8%, and 50.0% respectively. Subset analysis on patients without tumor recurrence/progression at long term follow-up (n = 62 pts, 51.2%) found that all patients with stable monitoring maintained or improved from preoperative status. One patient with transient intraoperative TC-MEP loss and permanent DC-MEP loss suffered a permanent deficit.

CONCLUSION

Brain tumor patients who undergo surgery with intact MEP monitoring and experience new postoperative deficits likely suffer transient deficits that will improve over the postoperative course in the absence of disease progression.

BRAINterns 2.0: Durability of Webinar-Based Education and Social Media Beyond the Coronavirus Disease 2019 Pandemic

BACKGROUND

Webinars offer novel educational opportunities beyond those of traditional, in-person experiences. BRAINterns is an open-access webinar-based education platform created to replace opportunities lost during the coronavirus disease 2019 pandemic. This program previously showed the efficacy of webinars to expand access to careers in medicine, and in particular, neurosurgery. BRAINterns 2.0 was established to assess the durability of Web-based learning.

METHODS

A modified 4-week webinar series was held during July 2021. A retrospective exit survey was distributed to participants and responses analyzed.

RESULTS

A total of 16,045 people registered for BRAINterns 2.0, representing 103 countries. Survey responses were received from 3765 participants (23% response rate). New, first-time registrants comprised 66% of participants, with the rest being returning participants. A total of 342 students participated in a dedicated module delivered entirely in Spanish. Females represented 81% of respondents. Participants identified that desirable elements of the program were opportunities to hear from women (53%) and people of color (44%) in health care. Participants heard about the series through TikTok (n = 1251; 33%), Instagram (n = 1109; 29%), Facebook (n = 637; 17%), and word of mouth (n = 708; 19%) with assistance from an ambassador program.

CONCLUSIONS

Webinar-based education programs continue to be of interest to students in an increasingly digital world. Social media, and specifically the use of educational ambassadors, are effective to improve visibility of educational programs across a diverse population of students. Understanding the desires of participants is critical to building a successful online education platform.

Stimulated Raman histology facilitates accurate diagnosis in neurosurgical patients: a one-to-one noninferiority study

OBJECTIVE

Stimulated Raman histology (SRH) offers efficient and accurate intraoperative neuropathological tissue analysis without procedural alteration to the diagnostic specimen. However, there are limited data demonstrating one-to-one tissue comparisons between SRH and traditional frozen sectioning. This study explores the non-inferiority of SRH as compared to frozen section on the same piece of tissue in neurosurgical patients.

METHODS

Tissue was collected over a 1-month period from 18 patients who underwent resection of central nervous system lesions. SRH and frozen section analyses were compared for diagnostic capabilities as well as assessed for quality and condition of tissue via a survey completed by pathologists.

RESULTS

SRH was sufficient for diagnosis in 78% of specimens as compared to 94% of specimens by frozen section of the same specimen. A Fisher's exact test determined there was no significant difference in diagnostic capability between the two groups. Additionally, both quality of SRH and condition of tissue after SRH were deemed to be non-inferior to frozen section.

CONCLUSIONS

This study provides further evidence for the non-inferiority of SRH techniques. It is also the first study to demonstrate SRH accuracy using one-to-one tissue analysis in neuropathological specimens.

Microsurgical management of complex hypothalamic hamartomas in the era of minimally invasive therapy: a case series and narrative review

INTRODUCTION

There has been a paradigm shift in the management of hypothalamic hamartoma (HH) from traditional microsurgical techniques to less invasive alternatives. However, large and extensive HH may fail to respond to these therapies, ultimately necessitating craniotomies.

METHODS

All patients who underwent microsurgical resection of a complex HH by the 2 senior authors from 2011-2021 were included. Charts were retrospectively reviewed and demographic, clinical, imaging, and outcome data were recorded.

RESULTS

8 patients (mean age 7 years) were included. 2 had failed previous treatments. All 7 presented with gelastic seizures and cognitive dysfunction, 6 exhibited central precocious puberty, and 3 had behavioral problems. Mean lesion size was 21.6 mm and all had interpeduncular extension, 5 had intraventricular extension (Delalande type I: 3, type III: 4, type IV: 1). A frontotemporal orbitozygomatic (FTOZ) approach with optic nerve decompression was used in all patients, supplemented by another approach in 3 (endoscopic transventricular: 3, transcallosal: 1). Gross total resection was achieved in 6 patients and subtotal resection in 2. Transient complications occurred in 3 patients (37.5%): self-limited sodium imbalance (n=3), subdural hygroma (n=2). Permanent complications occurred in 2 patients (25%): perforator infarct (n=1), short-term memory loss (n=1). All patients experienced seizure resolution with preserved hypothalamic-pituitary axis function. After a mean follow-up of 41 months (2-66), 7 patients remain seizure-free, while 1 has rare seizures. Cognitive and behavioral symptoms improved in all patients.

CONCLUSION

For large HH with interpeduncular extension, microsurgery via the FTOZ approach is a safe and highly effective treatment modality.

Repeated superselective intraarterial bevacizumab after blood brain barrier disruption for newly diagnosed glioblastoma: a phase I/II clinical trial

PURPOSE

Pre-clinical evidence suggests bevacizumab (BV) depletes the GBM peri-vascular cancer-stem cell niche. This phase I/II study assesses the safety and efficacy of repeated doses of superselective intra-arterial cerebral infusion (SIACI) of BV after blood-brain barrier disruption (BBBD).

METHODS

Date of surgery was day 0. Evaluated patients received repeated SIACI bevacizumab (15 mg/kg) with BBBD at days 30 ± 7, 120 ± 7, and 210 ± 7 along with 6 weeks of standard chemoradiation. Response assessment in neuro-oncology criteria and the Kaplan-Meier product-limit method was used to evaluate progression free and overall survival (PFS and OS, respectively).

RESULTS

Twenty-three patients with a median age of 60.5 years (SD = 12.6; 24.7-78.3) were included. Isocitrate dehydrogenase mutation was found in 1/23 (4%) patients. MGMT status was available for 11/23 patients (7 unmethylated; 3 methylated; 1 inconclusive). Median tumor volume was 24.0 cm3 (SD = 31.1, 1.7-48.3 cm³). Median PFS was 11.5 months (95% CI 7.7-25.9) with 6, 12, 24 and 60 month PFS estimated to be 91.3% (95% CI 69.5-97.8), 47.4% (26.3-65.9), 32.5% (14.4-52.2) and 5.4% (0.4-21.8), respectively. Median OS was 23.1 months (95% CI 12.2-36.9) with 12, 24, and 36 month OS as 77.3% (95% CI 53.6-89.9), 45.0% (22.3-65.3) and 32.1% (12.5-53.8), respectively.

CONCLUSIONS

Repeated dosing of IA BV after BBBD offers an encouraging outcome in terms of PFS and OS. Phase III trials are warranted to determine whether repeated IA BV combined with Stupp protocol is superior to Stupp protocol alone for newly diagnosed GBM.

Intraarterial delivery of bevacizumab and cetuximab utilizing blood-brain barrier disruption in children with high-grade glioma and diffuse intrinsic pontine glioma: results of a phase I trial

OBJECTIVE

Delivery of drugs intraarterially to brain tumors has been demonstrated in adults. In this study, the authors initiated a phase I trial of superselective intraarterial cerebral infusion (SIACI) of bevacizumab and cetuximab in pediatric patients with refractory high-grade glioma (diffuse intrinsic pontine glioma [DIPG] and glioblastoma) to determine the safety and efficacy in this population.

METHODS

SIACI was used to deliver mannitol (12.5 ml of 20% mannitol) to disrupt the blood-brain barrier (BBB), followed by bevacizumab (15 mg/kg) and cetuximab (200 mg/m2) to target VEGF and EGFR, respectively. Patients with brainstem tumors had a balloon inflated in the distal basilar artery during mannitol infusion.

RESULTS

Thirteen patients were treated (10 with DIPG and 3 with high-grade glioma). Toxicities included grade I epistaxis (2 patients) and grade I rash (2 patients). There were no dose-limiting toxicities. Of the 10 symptomatic patients, 6 exhibited subjective improvement; 92% showed decreased enhancement on day 1 posttreatment MRI. Of 10 patients who underwent MRI at 1 month, 5 had progressive disease and 5 had stable disease on FLAIR, whereas contrast-enhanced scans demonstrated progressive disease in 4 patients, stable disease in 2, partial response in 2, and complete response in 1. The mean overall survival for the 10 DIPG patients was 519 days (17.3 months), with a mean posttreatment survival of 214.8 days (7.2 months).

CONCLUSIONS

SIACI of bevacizumab and cetuximab was well tolerated in all 13 children. The authors' results demonstrate safety of this method and warrant further study to determine efficacy. As molecular targets are clarified, novel means of bypassing the BBB, such as intraarterial therapy and convection-enhanced delivery, become more critical. Clinical trial registration no.: NCT01884740 (clinicaltrials.gov).

Advances in Intraoperative Optics: A Brief Review of Current Exoscope Platforms

BACKGROUND

The advent of the operating microscope (OM) revolutionized the field of neurosurgery. It allowed surgeons to operate on and effectively treat diseases previously inaccessible with conventional eyesight because of magnification and illumination. Improvements in the essential methods of visualization and the quality of the optics have plateaued. Another main limitation of the OM remains its ergonomics because of the need of the surgeon and assistant to directly interface with the OM objective. Recently, exoscopes have been introduced to overcome some shortcomings of the conventional OM.

OBJECTIVE

To subjectively review the individual authors experience with the current exoscope platforms in an attempt to provide a resource to the neurosurgeon when considering imaging options.

METHODS

Experts with previous use of each individual platform were contacted and asked to contribute their experiences.

RESULTS

In total, 4 systems are discussed. They include the VITOM (Karl Storz, Tuttlingen, Germany), the Olympus ORBEYE (Olympus, Tokyo, Japan), the Synaptive Modus V (Synaptive Medical, Toronto, Canada), and the Zeiss KINEVO (Carl Zeiss AG, Oberkochen, Germany).

CONCLUSION

The advent of exoscopes has the potential to begin to allow surgeons to move beyond solely the microscope for intraoperative visualization while improving upon its ergonomic disadvantages.

A phase 1/2 study of selinexor in combination with standard of care therapy for newly diagnosed or recurrent glioblastoma

TPS2071

Background: Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor with a median overall survival (OS) of 15 months for patients with newly diagnosed GBM (ndGBM) and 5-7 months for patients with recurrent GBM (rGBM). To improve the prognosis of patients with GBM, novel therapies are urgently needed. Selinexor is a first-in class, oral, selective inhibitor of nuclear export that blocks exportin 1 (XPO1), forcing the nuclear retention and reactivation of tumor suppressor proteins, ultimately causing death of cancer cells. Selinexor is an FDA-approved treatment for patients with heavily pretreated multiple myeloma, for patients who received at least one prior therapy, and for patients with relapsed/refractory diffuse large B-cell lymphoma. Increased XPO1 expression in gliomas was associated with higher pathological stage and poorer prognosis. In a phase 2 study in rGBM (NCT01986348), selinexor demonstrated encouraging intratumoral penetration and single-agent efficacy at 80 mg once weekly with durable response and disease stabilization in heavily pretreated patients. In preclinical studies, selinexor showed synergy with radiation, temozolomide, or lomustine. The current trial tests the hypothesis that the addition of selinexor to standard therapy will improve clinical outcomes for patient with ndGBM or rGBM. Methods: This phase 1 dose finding study is followed by a 1:1 randomized phase 2 (n= 350) efficacy exploration trial to independently evaluate 3 regimens: Arm A – radiation +/- selinexor in unmethylated O6-methylguanine-DNA-methyltransferase (uMGMT) ndGBM; Arm B – radiation and temozolomide +/- selinexor in mMGMT ndGBM; Arm C – lomustine +/- selinexor in first relapsed rGBM following frontline radiation and temozolomide. The phase 1 primary endpoint is maximum tolerated dose/recommended phase 2 dose, with secondary endpoints of overall response rate (ORR) per modified Response Assessment in Neuro-Oncology (mRANO), duration of response (DOR), progression free survival (PFS), and OS. The phase 2 primary endpoint for Arms A and B in ndGBM is PFS, with key secondary endpoints being OS, PFS at 6 months, ORR, and DOR. For Arm C, the phase 2 primary endpoint is OS, while key secondary endpoints are PFS, PFS at 6 months, ORR, and DOR. The study has 70% power to detect a hazard ratio of 0.67 between selinexor and control for primary efficacy in Arms A and B, and 80% power to detect a hazard ratio of 0.70 for Arm C. We are currently enrolling patients nationwide. Clinical trial information: NCT04421378.

Web-Based Education and Social Media Increase Access to Careers in Neurosurgery: The Lenox Hill Hospital BRAINterns Experience

OBJECTIVE

To replace educational opportunities lost during the coronavirus disease 2019 (COVID-19) pandemic, the Department of Neurosurgery at Lenox Hill Hospital produced an open-access webinar series ("BRAINterns") that covered a broad range of health care topics with a focus on neurosurgery.

METHODS

This 8-week webinar series ran from July 1 to August 28, 2020. An optional exit survey was distributed to participants. Data were analyzed to characterize and better understand trends among a global cohort of participants.

RESULTS

A total of 16,484 people registered for BRAINterns, and 6675 took the survey (40.5% response rate). Responders represented 87 countries, of which the majority were from the United States and Canada (90.48%, n = 6039). Responders were primarily female (82.9%, n = 5521). Racial and ethnic representation was majority Asian (42%, n = 2798), followed by White (22.7%, n = 1514), Hispanic/Latino (16.2%, n = 1080), and Black and African American (7.7%, n = 516). Participants reported hearing about BRAINterns through various social media platforms (72.18%, n = 4818)-the most popular was TikTok (33.4%, n = 2232). Overall, 93.4% of participants reported that the course was a good use of their time during the pandemic, and 86.7% reported that the course helped replace lost opportunities.

CONCLUSIONS

These data demonstrate that webinar-based education is an effective method of expanding access to careers in medicine and in particular, neurosurgery, to traditionally underrepresented populations. Social media can be a powerful tool to combat barriers to early exposure and vastly improve diversity within the field.

First-in-Man Clinical Experience Using a High-Definition 3-Dimensional Exoscope System for Microneurosurgery

BACKGROUND

During its development and preclinical assessment, a novel, 3-dimensional (3D), high-definition (4K-HD) exoscope system was formerly shown to provide an immersive surgical experience, while maintaining a portable, low-profile design.

OBJECTIVE

To assess the clinical applicability of this 3D 4K-HD exoscope via first-in-man surgical use.

METHODS

The operative workflow, functionality, and visual haptics of the 3D 4K-HD exoscope were assessed in a variety of microneurosurgical cases at 2 US centers.

RESULTS

Nineteen microneurosurgical procedures in 18 patients were performed exclusively using the 3D 4K-HD exoscope. Pathologies treated included 4 aneurysms, 3 cavernous malformations (1 with intraoperative electrocorticography), 2 arteriovenous malformations, 1 foramen magnum meningioma, 1 convexity meningioma, 1 glioma, 1 occipital cyst, 1 chiari malformation, 1 carotid endarterectomy, 1 subdural hematoma, 1 anterior cervical discectomy and fusion, and 2 lumbar laminectomies. All patients experienced good surgical and clinical outcomes. Similar to preclinical assessments, the 3D 4K-HD exoscope provided an immersive 3D surgical experience for the primary surgeon, assistants, and trainees. The small exoscope frame, large depth of field, and hand/foot pedal controls improved exoscope mobility, decreased need to re-focus, and provided unobstructed operative corridors. Flexible positioning of the camera allows the surgeon's posture to be kept in a neutral position with uncompromised viewing angles.

CONCLUSION

The first-in-man clinical experience with the 3D 4K-HD exoscope confirms its excellent optics and ergonomics for the entire operative team, with high workflow adaptability for a variety of microneurosurgical cases. Expanded clinical use of the 3D 4K-HD exoscope is justified.

Vascularized Temporoparietal Fascial Flap: A Novel Surgical Technique to Bypass the Blood-Brain Barrier in Glioblastoma

BACKGROUND

The major difficulty in treating glioblastoma stems from the intrinsic privileged nature of the brain. This complicates therapy, as many traditionally potent chemotherapeutics cannot access their target sites in the brain. Several techniques have been investigated to overcome this barrier and facilitate drug delivery. However, these techniques have inherent shortcomings related to the delivery system, the drug itself, or its bioactivity. Periosteal flaps and temporoparietal fascial flaps (TPFFs) are widely used options because they have predictable vasculature and a wide rotational arc. These flaps are not restricted by the blood-brain barrier, as they derive their vascular supply from branches of the external carotid artery, which can be readily identified with Doppler ultrasound. We hypothesized that transposition of a vascularized TPFF to the walls of a resected tumor surgical cavity may bring autologous tissue not restricted by the blood-brain barrier in close vicinity of the resected tumor bed microenvironment. This offers a nonselective, long-lasting gateway to target the residual tumor cells nesting in the brain adjacent to the tumor.

CASE DESCRIPTION

A 47-year-old, right-handed woman with newly diagnosed multifocal glioblastoma underwent excision of the tumor and TPFF placement. This illustrative case report represents the first case of the use of this novel surgical technique with radiologic follow-up.

CONCLUSIONS

The blood-brain barrier is identified as a major barrier for effective drug delivery in glioblastoma. This study demonstrates the feasibility of the TPFF technique to bypass this barrier and help facilitate the goal of improving drug delivery.

A Roadmap to Reopening a Neurosurgical Practice in the Age of COVID-19

BACKGROUND

The Coronavirus disease 2019 (COVID-19) outbreak has left a lasting mark on medicine globally.

METHODS

Here we outline the steps that the Lenox Hill Hospital/Northwell Health Neurosurgery Department-located within the epicenter of the pandemic in New York City-is currently taking to recover our neurosurgical efforts in the age of COVID-19.

RESULTS

We outline measurable milestones to identify the transition to the recovery period and hope these recommendations may serve as a framework for an effective path forward.

CONCLUSIONS

We believe that recovery following the COVID-19 pandemic offers unique opportunities to disrupt and rebuild the historical patient and office experience as we evolve with modern medicine in a post-COVID-19 world.

Neuroradiological and Neuropathological Changes After 177Lu-Octreotate Peptide Receptor Radionuclide Therapy of Refractory Esthesioneuroblastoma

BACKGROUND AND IMPORTANCE

Olfactory neuroblastoma, also known as esthesioneuroblastoma (ENB), is a malignant neoplasm with an unpredictable behavior. Currently, the widely accepted treatment is inductive chemotherapy, with or without surgery, followed by radiotherapy. Since data on genetics and molecular alterations of ENB are lacking, there is no standard molecularly targeted therapy. However, ENB commonly expresses the somatostatin receptor (SSTR) that is also expressed by neuroendocrine tumors. Peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin analogues, such as 177Lu-octreotate, is an effective treatment for the latter. We present the complex neuroradiological and neuropathological changes associated with 177Lu-octreotate treatment of a patient with a highly treatment-resistant ENB.

CLINICAL PRESENTATION

A 60-yr-old male presented with an ENB that recurred after chemotherapy, surgery, stereotactic radiosurgery, and immunotherapy. Pathology revealed a Hyams grade 3 ENB and the tumor had metastasized to lymph nodes. Tumor SSTR expression was seen on 68Ga-octreotate positron emission tomography (PET)/computed tomography (CT), suggesting that PRRT may be an option. He received 4 cycles of 177Lu-octreotate over 6 mo, with a partial response of all lesions and symptomatic improvement. Four months after the last PRRT cycle, 2 of the lesions rapidly relapsed and were successfully resected. Three months later, 68Ga-octreotate PET/CT and magnetic resonance imaging indicate no progression of the disease.

CONCLUSION

We describe imaging changes associated with 177Lu-octreotate PRRT of relapsing ENB. To our knowledge, this is the first report describing neuropathological changes associated with this treatment. PRRT is a promising therapeutic option to improve the disease control, and potentially, the survival of patients with refractory ENB.

Rechallenging Recurrent Glioblastoma with Intra-Arterial Bevacizumab with Blood Brain-Barrier Disruption Results in Radiographic Response

BACKGROUND

High-dose bevacizumab delivered via super selective intra-arterial cerebral infusion (SIACI) is one promising clinical trial combination for patients with glioblastoma (GBM). Although both continuous intravenous and intra-arterial administration of bevacizumab, and rechallenge with intravenous bevacizumab, have demonstrated improved survival, this is the first description of rechallenging GBM with SIACI of bevacizumab.

CASE DESCRIPTION

We report a case of a 43-year-old woman with recurrent GBM who had received treatment from 3 clinical trials, including a rechallenge with SIACI of bevacizumab. First, she enrolled into a phase I/II trial for patients newly diagnosed with GBM (NCT01811498) and received 3 doses of SIACI bevacizumab over 180 days in addition to standard of care chemotherapy and radiation. Following progression, as indicated on her magnetic resonance imaging scan, she consented for a separate clinical trial for her disease and received 2 cycles of temozolomide with an investigational agent. The patient was removed from the study on tumor progression. Subsequently, she was rechallenged with SIACI of bevacizumab via a third clinical trial (NCT01269853) and then completed 3 intravenous infusions. After completing the third trial, her magnetic resonance imaging scan demonstrated improvement based on Response Assessment In Neuro-Oncology criteria.

CONCLUSIONS

This is the first report to highlight the effect of rechallenging a patient with SIACI of bevacizumab following disease progression after initial bevacizumab treatment and subsequent alternate clinical trial failure. There is a need to conduct further clinical trials to evaluate the benefits of rechallenge with SIACI versus intravenous bevacizumab for GBM and further explore theories of bevacizumab resistance.

Electrophysiological Mapping and Monitoring during an Awake Craniotomy for Low-Grade Glioma: Case Report

Awake craniotomy is advocated for the resection of supratentorial low-grade gliomas (LGG). The combination of neurophysiological electrical mapping techniques and performing the craniotomy awake has demonstrated increased total and supratotal resection of LGG, as well as increased overall survival rates. We present an illustrative case where the patient's gross motor function deteriorated during the resection of a LGG and mapping techniques using the phase reversal technique and Taniguchi direct cortical stimulation technique while the patient was awake proved to be valuable in determining continuity of the corticospinal tracts.

Technical Aspects and Operative Nuances Using a High-Definition 3-Dimensional Exoscope for Cerebral Bypass Surgery

BACKGROUND

Cerebral bypass operation is a technically challenging operation that requires excellent surgical visibility and efficient ergonomics to minimize complications and maximize successful revascularization. Despite the operative microscope's utilization for the past two generations, there remains a need for continued improvement in operative visualization and surgical ergonomics.

OBJECTIVE

To report the positives and negatives of our initial experience using a novel 4 K high-definition (4K-HD) 3-dimensional (3D) exoscope (EX) for cranial bypass surgery.

METHODS

A retrospective review over 6 mo was performed of all patients who have undergone cerebral bypass surgery at a single institution using the 4K-HD 3D EX. Advantages and disadvantages of the EX and clinical outcome of the patients were assessed.

RESULTS

A total of 5 patients underwent cerebral EC-IC bypass surgery with no EX-related complications and successful revascularization. The lightweight design of the EX allowed for easy instrument maneuverability as well as uncomplicated surgical set up in the operating room. The assistance of the cosurgeon was significantly more efficient compared to that of the operating microscope. The large monitor allowed for an immersive, collaborative, and valuable educational surgical experience.

CONCLUSION

Using the EX for cerebral bypass surgery, with 3D ultra-high-definition optics, enhancements of ergonomics, and improved training, we believe that the 3D 4K-HD EX may represent the next generation of operative scopes in microneurosurgery.

Lessons Learned Using a High-Definition 3-Dimensional Exoscope for Spinal Surgery

BACKGROUND

The operative microscope has significantly advanced modern neurosurgical spine surgery but continues to be limited by high costs, suboptimal optics, poor ergonomics, and difficulties with maneuverability. We believe the novel 4K high-definition (4K-HD) 3-dimensional (3D) exoscope (EX), may improve the surgical corridor through advancements in illumination, ergonomics, magnification, and depth of field and has the potential to be utilized in neurosurgical education and training.

OBJECTIVE

To evaluate the surgical potential of a novel 3D EX system in spinal surgery.

METHODS

Retrospective analysis over 6 mo of all patients who have undergone spinal surgery at Northwell Health using the 3D EX. Nuances of surgical theater positioning, advantages/disadvantages of the EX and clinical sequelae of the patients were analyzed.

RESULTS

All 10 patients who underwent spinal surgery utilizing the EX experienced excellent surgical and clinical outcomes without complications. The low-profile EX allowed for excellent operative corridors and instrument maneuverability. The large monitor also resulted in an immersive surgical experience, and gave team members the same 3D vision as the operator.

CONCLUSION

This study demonstrates the feasibility of utilizing the 3D 4K-HD EX system and highlights potential technical assets of this novel technology in regard to optics, ergonomics, and maneuverability. Further clinical research is needed to examine the clinical effectiveness of the EX system for different surgical approaches through quantitative methodology.

Do craniopharyngioma molecular signatures correlate with clinical characteristics?

OBJECTIVE

Exome sequencing studies have recently demonstrated that papillary craniopharyngiomas (PCPs) and adamantinomatous craniopharyngiomas (ACPs) have distinct genetic origins, each primarily driven by mutually exclusive alterations: either BRAF (V600E), observed in 95% of PCPs, or CTNNB1, observed in 75%–96% of ACPs. How the presence of these molecular signatures, or their absence, correlates with clinical, radiographic, and outcome variables is unknown.

METHODS

The pathology records for patients who underwent surgery for craniopharyngiomas between May 2000 and March 2015 at Weill Cornell Medical College were reviewed. Craniopharyngiomas were identified and classified as PCP or ACP. Patients were placed into 1 of 3 groups based on their genomic mutations: BRAF mutation only, CTNNB1 mutation only, and tumors with neither of these mutations detected (not detected [ND]). Demographic, radiological, and clinical variables were collected, and their correlation with each genomic group was tested.

RESULTS

Histology correlated strongly with mutation group. All BRAF tumors with mutations were PCPs, and all CTNNB1 with mutations and ND tumors were ACPs. Preoperative and postoperative clinical symptoms and radiographic features did not correlate with any mutation group. There was a statistically significant relationship (p = 0.0323) between the age group (pediatric vs adult) and the mutation groups. The ND group tumors were more likely to involve the sella (p = 0.0065).

CONCLUSIONS

The mutation signature in craniopharyngioma is highly predictive of histology. The subgroup of tumors in which these 2 mutations are not detected is more likely to occur in children, be located in the sella, and be of ACP histology.

Superselective intraarterial cerebral infusion of cetuximab with blood brain barrier disruption combined with Stupp Protocol for newly diagnosed glioblastoma

We describe the first case of a novel treatment for a newly diagnosed glioblastoma (GBM) using superselective intraarterial cerebral infusion (SIACI) of cetuximab after osmotic disruption of the blood-brain barrier (BBB) with mannitol. A 51year-old female underwent craniotomy for removal of a right frontal GBM. Pathology confirmed EGFR amplification, and she underwent three treatments of SIACI of cetuximab to the tumor site. The first treatment was given within a week of starting standard of care chemoradiation (Stupp protocol), which is a combination of radiation treatment (2 Gy per/ day x 30 days, total of 60 Gy) and oral temozolomide (75 mg/m²). The second and third SIACI of cetuximab were administered 3 and 6 months later, while the patient continued on maintenance temozolomide. Post-radiation changes on MRI were stable, and there were no signs of recurrence at 4 and 6 months post-resection. Herein, we detail the technical aspects of this novel treatment paradigm and suggest that SIACI of cetuximab after BBB disruption using mannitol, combined with the standard of care chemoradiation therapy, may be an effective treatment method for newly diagnosed EGFR amplified glioblastoma.