High-resolution neural recordings improve the accuracy of speech decoding

Patients suffering from debilitating neurodegenerative diseases often lose the ability to communicate, detrimentally affecting their quality of life. One solution to restore communication is to decode signals directly from the brain to enable neural speech prostheses. However, decoding has been limited by coarse neural recordings which inadequately capture the rich spatio-temporal structure of human brain signals. To resolve this limitation, we performed high-resolution, micro-electrocorticographic (µECoG) neural recordings during intra-operative speech production. We obtained neural signals with 57× higher spatial resolution and 48% higher signal-to-noise ratio compared to macro-ECoG and SEEG. This increased signal quality improved decoding by 35% compared to standard intracranial signals. Accurate decoding was dependent on the high-spatial resolution of the neural interface. Non-linear decoding models designed to utilize enhanced spatio-temporal neural information produced better results than linear techniques. We show that high-density µECoG can enable high-quality speech decoding for future neural speech prostheses.

Recombinant polio-rhinovirus immunotherapy for recurrent paediatric high-grade glioma: a phase 1b trial

BACKGROUND

Outcomes of recurrent paediatric high-grade glioma are poor, with a median overall survival of less than 6 months. Viral immunotherapy, such as the polio-rhinovirus chimera lerapolturev, is a novel approach for treatment of recurrent paediatric high-grade glioma and has shown promise in adults with recurrent glioblastoma. The poliovirus receptor CD155 is ubiquitously expressed in malignant paediatric brain tumours and is a treatment target in paediatric high-grade glioma. We aimed to assess the safety of lerapolturev when administered as a single dose intracerebrally by convection enhanced delivery in children and young people with recurrent WHO grade 3 or grade 4 glioma, and to assess overall survival in these patients.

METHODS

This phase 1b trial was done at the Duke University Medical Center (Durham, NC, USA). Patients aged 4-21 years with recurrent high-grade malignant glioma (anaplastic astrocytoma, glioblastoma, anaplastic oligoastrocytoma, anaplastic oligodendroglioma, or anaplastic pleomorphic xanthoastrocytoma) or anaplastic ependymoma, atypical teratoid rhabdoid tumour, or medulloblastoma with infusible disease were eligible for this study. A catheter was tunnelled beneath the scalp for a distance of at least 5 cm to aid in prevention of infection. The next day, lerapolturev at a dose of 5 × 107 median tissue culture infectious dose in 3 mL infusate loaded in a syringe was administered via a pump at a rate of 0·5 mL per h as a one-time dose. The infusion time was approximately 6·5 h to compensate for volume of the tubing. The primary endpoint was the proportion of patients with unacceptable toxic effects during the 14-day period after lerapolturev treatment. The study is registered with ClinicalTrials.gov, NCT03043391.

FINDINGS

Between Dec 5, 2017, and May 12, 2021, 12 patients (11 unique patients) were enrolled in the trial. Eight patients were treated with lerapolturev. The median patient age was 16·5 years (IQR 11·0-18·0), five (63%) of eight patients were male and three (38%) were female, and six (75%) of eight patients were White and two (25%) were Black or African American. The median number of previous chemotherapeutic regimens was 3·50 (IQR 1·25-5·00). Six of eight patients had 26 treatment-related adverse events attributable to lerapolturev. There were no irreversible (ie, persisted longer than 2 weeks) treatment-related grade 4 adverse events or deaths. Treatment-related grade 3 adverse events included headaches in two patients and seizure in one patient. Four patients received low-dose bevacizumab on-study for treatment-related peritumoural inflammation or oedema, diagnosed by both clinical symptoms plus fluid-attenuated inversion recovery MRI. The median overall survival was 4·1 months (95% CI 1·2-10·1). One patient remains alive after 22 months.

INTERPRETATION

Convection enhanced delivery of lerapolturev is safe enough in the treatment of recurrent paediatric high-grade glioma to proceed to the next phase of trial.

FUNDING

Solving Kids Cancer, B+ Foundation, Musella Foundation, and National Institutes of Health.

Indication for a skull base approach in microvascular decompression for hemifacial spasm

BACKGROUND

A thorough observation of the root exit zone (REZ) and secure transposition of the offending arteries is crucial for a successful microvascular decompression (MVD) for hemifacial spasm (HFS). Decompression procedures are not always feasible in a narrow operative field through a retrosigmoid approach. In such instances, extending the craniectomy laterally is useful in accomplishing the procedure safely. This study aims to introduce the benefits of a skull base approach in MVD for HFS.

METHODS

The skull base approach was performed in twenty-eight patients among 335 consecutive MVDs for HFS. The site of the neurovascular compression (NVC), the size of the flocculus, and the location of the sigmoid sinus are measured factors in the imaging studies. The indication for a skull base approach is evaluated and verified retrospectively in comparison with the conventional retrosigmoid approach. Operative outcomes and long-term results were analyzed retrospectively.

RESULTS

The extended retrosigmoid approach was used for 27 patients and the retrolabyrinthine presigmoid approach was used in one patient. The measurement value including the site of NVC, the size of the flocculus, and the location of the sigmoid sinus represents well the indication of the skull base approach, which is significantly different from the conventional retrosigmoid approach. The skull base approach is useful for patients with medially located NVC, a large flocculus, or repeat MVD cases. The long-term result demonstrated favorable outcomes in patients with the skull base approach applied.

CONCLUSIONS

Preoperative evaluation for lateral expansion of the craniectomy contributes to a safe and secure MVD.

Second Case of Tumors Associated With Heterozygous NTHL1 Variant

Homozygous mutations to NTHL1 are known to increase cancer risk, particularly in the colon and breast. NTHL1 tumor syndrome (NTS) is an autosomal recessive genetic condition. Little is known about the cancer risk in patients who have heterozygous NTHL1 mutations. We previously published a case of benign tumors associated with a heterozygous NTHL1 mutation. In this second case, we present a patient with a heterozygous NTHL1 mutation who developed a gastrointestinal stromal tumor, pilocytic astrocytoma, tall cell papillary thyroid cancer, invasive ductal papilloma, spinal nerve sheath tumors, and spinal hemangiomas. Here, we show that heterozygous NTHL1 mutations may increase cancer risk and may even manifest similarly to NTS.

A phase 0/surgical window-of-opportunity study in progress, evaluating evolocumab in patients with high-grade glioma or glioblastoma

TPS2076

Background: High-grade gliomas (HGGs) are immunologically ‘cold’ tumors. This phenomenon is partly due to reduced expression of major histocompatibility class (MHC) I on the surface of tumor cells, which prevents CD8+ cytotoxic T lymphocyte activity (CTLs). Blockade of proprotein convertase subtilisin/kexin type 9 (PCSK9) increases MHC class I expression, enhances CTL tumoral infiltration, and potentiates checkpoint inhibition in vivo. Evolocumab is an FDA-approved fully human IgG2 monoclonal antibody PCSK9 inhibitor which is clinically indicated for hyperlipidemia. This study seeks to determine whether evolocumab can cross the blood-brain barrier (BBB) and enhance MHC I expression on resected tumor cells, serving as a potential future adjunct for immunotherapy. Methods: This study will enroll ten patients over 18 years who have newly diagnosed or recurrent HGG. These patients will also need to be undergoing resection of their tumor as part of their planned treatment pathway. Following informed consent, patients will receive evolocumab (420mg, subcutaneously) 7-14 days before surgical debulking of the tumor. We will collect tissue which is not required for histological tumor analysis and compare it with a contemporaneous matched control cohort. This will consist of resected tumor specimens from patients not treated with evolocumab. Quantification of the drug will be performed using mass spectroscopy, flow cytometry, and single-cell sequencing. The primary objective of this study is to evaluate whether evolocumab can cross the BBB and be measured in resected tumor specimens taken from patients with HGG. Secondary objectives include an analysis of lipid metabolism and MHC-I expression on the tumor via flow cytometry and CITEseq. Wilcoxon rank-sum test or a two-sample t-test, will compare groups for these endpoints. Exploratory analyses will determine if evolocumab leads to changes in tumorigenic pathways and the immune profile of tumor infiltrating lymphocytes (TILs). Bioinformatic analyses will be performed using protein set enrichment, gene ontology (GO) annotations, and search tools from the retrieval of interactive genes/proteins (STRING). Progress: The study was activated on 10/04/2021 (NCT04937413) and at the time of submission has enrolled 5 participants (4 to control arm, 1 to intervention arm). Clinical trial information: NCT04937413.

Reproducibility of outcomes in sequential trials using CMV-targeted dendritic cell vaccination for glioblastoma

2005

Background: Vaccination with dendritic cells (DCs) fares poorly in primary and recurrent glioblastoma (GBM). Moreover, GBM vaccine trials are often underpowered due to limited sample size. Methods: To address these limitations, we conducted three sequential clinical trials utilizing Cytomegalovirus (CMV)-specific DC vaccines in patients with newly diagnosed GBM eligible to receive standard of care resection and adjuvant radiation therapy and temozolomide chemotherapy. Autologous DCs were generated and electroporated with mRNA encoding for the CMV protein pp65. Serial vaccination was given throughout adjuvant temozolomide cycles, and 111Indium radiolabeling was implemented to assess migration efficiency of DC vaccines. Patients were followed for median overall survival (mOS) and OS. Results: Our initial study was the phase II ATTAC study (NCT00639639; total n = 12) with 6 patients randomized to vaccine site preconditioning with tetanus-diphtheria (Td) toxoid. This led to an expanded cohort trial (ATTAC-GM; NCT00639639) of 11 patients receiving CMV DC vaccines containing granulocyte-macrophage colony-stimulating factor (GM-CSF). Follow-up data from ATTAC and ATTAC-GM revealed 5-year OS rates of 33.3% (mOS 38.3 months; CI95 17.5-undefined) and 36.4% (mOS 37.7 months; CI95 18.2-109.1), respectively. ATTAC additionally revealed a significant increase in DC migration to draining lymph nodes following Td preconditioning ( P = 0.049). Increased DC migration was associated with OS (Cox proportional hazards model, HR = 0.820, P = 0.023). Td-mediated increased migration has been recapitulated in our larger confirmatory trial ELEVATE (NCT02366728) of 43 patients randomized to preconditioning (Wilcoxon rank sum, Td n = 24, unpulsed DC n = 19; 24h, P = 0.031 and 48h, P = 0.0195). In ELEVATE, median follow-up of 42.2 months revealed significantly longer OS in patients randomized to Td ( P = 0.026). The 3-year OS for Td-treated patients in ELEVATE was 34% (CI95 19-63%) compared to 6% given unpulsed DCs (CI95 1-42%). Conclusions: We report reproducibility of our findings across three sequential clinical trials using CMV pp65 DCs. Despite their small numbers, these successive trials demonstrate consistent survival outcomes, thus supporting the efficacy of CMV DC vaccine therapy in GBM. Clinical trial information: NCT00639639, NCT02366728.

A phase 1 trial of D2C7-it in combination with an Fc-engineered anti-CD40 monoclonal antibody (2141-V11) administered intratumorally via convection-enhanced delivery for adult patients with recurrent malignant glioma (MG)

e14015

Background: D2C7 immunotoxin (D2C7-IT) is a dual-specific recombinant immunotoxin comprising an EGFR wild-type and mutant-specific (EGFRvIII) monoclonal antibody (Ab) fragment and a genetically engineered form of the Pseudomonas exotoxin. When injected directly into the tumor by convection enhanced delivery (CED), immunotoxins induce both direct tumor killing and secondary immune responses by activation of CD4+ and CD8+ T-cells. Tumor-associated macrophages (TAMs) are the most prominent glioma-infiltrating immune cells and constitute up to 40% of the tumor mass. Upon binding of D2C7-IT to EGFR and cellular internalization, the Pseudomonas exotoxin moiety of the D2C7-IT kills residual GBM cells, upregulates proinflammatory CD40, and induces pattern recognition receptor pathway transcriptome expression. This potentially creates a proinflammatory glioma microenvironment where TAM activation may be further stimulated by sequential CED of 2141-V11, an Fc engineered anti-human CD40 agonist antibody developed at Rockefeller University. We are conducting a first in human trial of the combination of D2C7-IT + 2141-V11 administered via CED in recurrent MG patients. Methods: Eligibility includes adult patients with recurrence of a solitary supratentorial WHO grade 3 or 4 MG; ≥ 4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; and KPS ≥ 70%. Cohorts of 3 patients are treated with increasing levels of 2141-V11 to determine the maximum tolerated dose (MTD) of the compound administered intratumorally in conjunction with D2C7-IT. Dose escalation and de-escalation are managed using a modified Bayesian optimal interval (BOIN) design to identify the MTD. Intratumoral administration of D2C7-IT via CED (4612 ng/mL over 72 hours) is followed by a 7-hour infusion of 2141-V11, both infused at 0.5 mL/hr. 2141-V11 is dose-escalated to determine the MTD when combined with D2C7-IT. Four dose levels (DL) are planned: #1: 0.70 mg; #2: 2.0 mg; #3: 7.0 mg; #4: 21.0 mg. Results: As of February 7, 2022, three patients were treated at DL1 and DL2, and two patients at DL3. No DLTs have been observed, and all eight patients remain alive and in observation on study after 7.0, 6.5, 6.0, 4.4, 2.8, 2.4, 0.9 and 0.5 months. Early signs of tumor response have been observed, with one patient at DL1 and 2 patients at DL2 without radiographic evidence of active tumor. Grade 2 or higher AEs due to D2C7-IT and/or 2141-V11 include: headache (grade 3, n = 1; grade 2, n = 2); paresthesia (grade 3, n = 1; grade 2, n = 1); dysphasia (grade 3, n = 1); pyramidal tract disorder (grade 3, n = 1; grade 2, n = 1); and depressed level of consciousness (grade 2, n = 1). Enrollment is ongoing. Conclusions: Intratumoral administration of D2C7-IT + 2141-V11 via CED is safe, and encouraging efficacy results have been observed. Clinical trial information: NCT04547777.

Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array

One-third of epilepsy patients suffer from medication-resistant seizures. While surgery to remove epileptogenic tissue helps some patients, 30-70% of patients continue to experience seizures following resection. Surgical outcomes may be improved with more accurate localization of epileptogenic tissue. We have previously developed novel thin-film, subdural electrode arrays with hundreds of microelectrodes over a 100-1000 mm2 area to enable high-resolution mapping of neural activity. Here, we used these high-density arrays to study microscale properties of human epileptiform activity. We performed intraoperative micro-electrocorticographic recordings in nine patients with epilepsy. In addition, we recorded from four patients with movement disorders undergoing deep brain stimulator implantation as non-epileptic controls. A board-certified epileptologist identified microseizures, which resembled electrographic seizures normally observed with clinical macroelectrodes. Recordings in epileptic patients had a significantly higher microseizure rate (2.01 events/min) than recordings in non-epileptic subjects (0.01 events/min; permutation test, P = 0.0068). Using spatial averaging to simulate recordings from larger electrode contacts, we found that the number of detected microseizures decreased rapidly with increasing contact diameter and decreasing contact density. In cases in which microseizures were spatially distributed across multiple channels, the approximate onset region was identified. Our results suggest that micro-electrocorticographic electrode arrays with a high density of contacts and large coverage are essential for capturing microseizures in epilepsy patients and may be beneficial for localizing epileptogenic tissue to plan surgery or target brain stimulation.

Long-Term Outcomes for Patients With Atypical or Malignant Meningiomas Treated With or Without Radiation Therapy: A 25-Year Retrospective Analysis of a Single-Institution Experience

Purpose

Atypical (World Health Organization [WHO] grade 2) and malignant (WHO grade 3) meningiomas have high rates of local recurrence, and questions remain about the role of adjuvant radiation therapy (RT) for patients with WHO grade 2 disease. These patients frequently require salvage therapy, and optimal management is uncertain given limited prospective data. We report on the long-term outcomes for patients with atypical and malignant meningiomas treated with surgery and/or RT at our institution.

Methods and Materials

Data were collected through a retrospective chart review for all patients with WHO grade 2 or 3 meningiomas treated with surgery and/or RT at our institution between January 1992 and March 2017. Progression-free survival (PFS) and overall survival (OS) were described using the KaplanMeier estimator. The outcomes in the subgroups were compared with a log-rank test. A Cox proportional hazards model was used for the univariable and multivariable analyses of predictors of PFS.

Results

A total of 66 patients were included in this analysis. The median follow-up was 12.4 years overall and 8.6 years among surviving patients. Fifty-two patients (78.8%) had WHO grade 2 meningiomas, and 14 patients (21.2%) had WHO grade 3 disease. Thirty-six patients (54.5%) were treated with surgery alone, 28 patients (42.4%) with surgery and adjuvant RT, and 2 patients (3%) with RT alone. Median PFS and OS were 3.2 years and 8.8 years, respectively. PFS was significantly improved with adjuvant RT compared with surgery alone (hazard ratio, 0.36; 95% confidence interval, 0.18-0.70). Patients with Ki-67 index >10% showed a trend toward worse PFS compared with patients with Ki-67 ≤10% (hazard ratio, 0.51; 95% confidence interval, 0.25-1.04). No significant differences in PFS or OS were observed with respect to Simpson or WHO grade.

Conclusions

For patients with atypical or malignant meningiomas, adjuvant RT was associated with significantly improved PFS, and Ki-67 index >10% was associated with a trend toward worse PFS. Given the long-term survival, high recurrence rates, and efficacy of salvage therapy, patients with atypical and malignant meningiomas should be monitored systematically long after initial treatment.

Retrolabyrinthine transsigmoid approach to complex parabrainstem tumors in the posterior fossa

OBJECTIVE

The surgical management of large and complex tumors of the posterior fossa poses a formidable challenge in neurosurgery. The standard retrosigmoid craniotomy approach has been performed at most neurosurgical centers; however, the retrosigmoid approach may not provide enough working space without significant retraction of the cerebellum. The transsigmoid approach provides wider and shallower surgical fields; however, there have been few clinical and no cadaveric studies on its usefulness. In the present study, the authors describe the transsigmoid approach in clinical cases and cadaveric specimens.

METHODS

For the clinical study, the authors retrospectively reviewed the medical records and operative charts of patients who had been surgically treated for parabrainstem tumors using the transsigmoid approach between 1997 and 2019. They analyzed patient demographic and clinical data, as well as surgical and clinical outcomes. In the cadaveric study, they compared the surgical views obtained in different approaches (retrosigmoid, presigmoid, retrolabyrinthine, and transsigmoid) and measured the sigmoid sinus width at the level of the endolymphatic sac and the distance between the anterior edge of the sigmoid sinus and the endolymphatic sac on 35 sides in 19 cadaveric specimens.

RESULTS

A total of 21 patients (6 males and 15 females) with a mean age of 42.2 (range 15-67) years were included in the clinical study. Eleven patients had meningioma, 7 had vestibular schwannoma, 2 had hemangioblastoma, and 1 had epidermoid cyst. Gross-total, near-total, and subtotal removal were achieved in 7 (33.3%), 3 (14.3%), and 11 (52.4%) patients, respectively. In the cadaveric study, 19 cadaveric specimens were used. The sigmoid sinus was cut in the middle, and the incision was extended from the retrosigmoid to the presigmoid dura. The dura was then retracted upward and downward like opening a door. The results indicated that this technique can widen the operative field anteriorly by approximately 2 cm as compared to the retrosigmoid approach and provides a better view anterior to the brainstem.

CONCLUSIONS

The transsigmoid approach is useful for complex parabrainstem tumors in the posterior fossa because it provides a wider and shallower operative view with less retraction of the cerebellum. This enables safer tumor removal with less damage to important structures in the posterior fossa, resulting in better operative and clinical outcomes.

Neurosurgical management of petrous bone lesions: classification system and selection of surgical approaches

BACKGROUND

Surgery of petrous bone lesions (PBLs) is challenging for neurosurgeons. Selection of the surgical approach is an important key for success. In this study, the authors present an anatomical classification for PBLs that has been used by our group for over the past 26 years. The objective of this study is to investigate the benefits and applicability of this classification.

METHODS

Between 1994 and 2019, 117 patients treated for PBLs were retrospectively reviewed. Using the V3 and arcuate eminence as reference points, the petrous bone is segmented into 3 parts: petrous apex, rhomboid, and posterior. The pathological diagnoses, selection of the operative approach, and the extent of resection (EOR) were analyzed and correlated using this classification.

RESULTS

This series included 22 facial nerve schwannomas (18.8%), 22 cholesterol granulomas (18.8%), 39 chordomas/chondrosarcomas (33.3%), 6 trigeminal schwannomas (5.1%), 13 epidermoids/dermoids (11.1%), and 15 other pathologies (12.8%). PBLs were most often involved with the petrous apex and rhomboid areas (46.2%). The extradural subtemporal approach (ESTA) was most frequently used (57.3%). Gross total resection was achieved in 58.4%. Symptomatic improvement occurred in 92 patients (78.6%). Our results demonstrated a correlation between this classification with each type of pathology (p < .001), selection of surgical approaches (p < 0.001), and EOR (p = 0.008). Chordoma/chondrosarcoma, redo operations, and lesions located medially were less likely to have total resection. Temporary complications occurred in 8 cases (6.8%), persistent morbidity in 5 cases (4.3%), and mortality in 1 case.

CONCLUSION

In this study, we proposed a simple classification of PBLs. Using landmarks on the superior petrosal surface, the petrous bone is divided into 3 parts, apex, rhomboid, and posterior. Our results demonstrated that chordoma/chondrosarcoma, redo operations, and lesions involving the tip of the petrous apex or far medial locations were more difficult to achieve total resection. This classification could help surgeons understand surgical anatomy framework, predict possible structures at risk, and select the most appropriate approach for each patient.

How I do it: total resection of a giant sphenoclinoidal meningioma with normalization of near blind vision

BACKGROUND

Resection of giant sphenoclinoidal meningiomas (SCLM) remains difficult. We discuss a patient presenting with right eye near blindness who underwent total removal of a giant SCLM, resulting in normal vision and no recurrence.

METHOD

Utilizing frontotemporal craniotomy, devascularization, debulking, and detachment was achieved. Microdissection of tumor off the optic nerve and carotid perforators was accomplished, resulting in total resection, visual normalization, and no deficits using efficient face-to-face microscope set-up, 2-surgeon 4-hand technique, and double bipolar-suction arrangement.

CONCLUSION

Frontotemporal craniotomy was adequate. Preservation of the optic nerve and carotid artery is key. Meticulous microsurgical techniques and refined instruments are important for success.

Neurosurgery residency and fellowship education in the United States: 2 decades of system development by the One Neurosurgery Summit organizations

The purpose of this report is to chronicle a 2-decade period of educational innovation and improvement, as well as governance reform, across the specialty of neurological surgery. Neurological surgery educational and professional governance systems have evolved substantially over the past 2 decades with the goal of improving training outcomes, patient safety, and the quality of US neurosurgical care. Innovations during this period have included the following: creating a consensus national curriculum; standardizing the length and structure of neurosurgical training; introducing educational outcomes milestones and required case minimums; establishing national skills, safety, and professionalism courses; systematically accrediting subspecialty fellowships; expanding professional development for educators; promoting training in research; and coordinating policy and strategy through the cooperation of national stakeholder organizations. A series of education summits held between 2007 and 2009 restructured some aspects of neurosurgical residency training. Since 2010, ongoing meetings of the One Neurosurgery Summit have provided strategic coordination for specialty definition, neurosurgical education, public policy, and governance. The Summit now includes leadership representatives from the Society of Neurological Surgeons, the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, the American Board of Neurological Surgery, the Review Committee for Neurological Surgery of the Accreditation Council for Graduate Medical Education, the American Academy of Neurological Surgery, and the AANS/CNS Joint Washington Committee. Together, these organizations have increased the effectiveness and efficiency of the specialty of neurosurgery in advancing educational best practices, aligning policymaking, and coordinating strategic planning in order to meet the highest standards of professionalism and promote public health.

Flexible, high-resolution thin-film electrodes for human and animal neural research

Objective.Brain functions such as perception, motor control, learning, and memory arise from the coordinated activity of neuronal assemblies distributed across multiple brain regions. While major progress has been made in understanding the function of individual neurons, circuit interactions remain poorly understood. A fundamental obstacle to deciphering circuit interactions is the limited availability of research tools to observe and manipulate the activity of large, distributed neuronal populations in humans. Here we describe the development, validation, and dissemination of flexible, high-resolution, thin-film (TF) electrodes for recording neural activity in animals and humans.Approach.We leveraged standard flexible printed-circuit manufacturing processes to build high-resolution TF electrode arrays. We used biocompatible materials to form the substrate (liquid crystal polymer; LCP), metals (Au, PtIr, and Pd), molding (medical-grade silicone), and 3D-printed housing (nylon). We designed a custom, miniaturized, digitizing headstage to reduce the number of cables required to connect to the acquisition system and reduce the distance between the electrodes and the amplifiers. A custom mechanical system enabled the electrodes and headstages to be pre-assembled prior to sterilization, minimizing the setup time required in the operating room. PtIr electrode coatings lowered impedance and enabled stimulation. High-volume, commercial manufacturing enables cost-effective production of LCP-TF electrodes in large quantities.Main Results. Our LCP-TF arrays achieve 25× higher electrode density, 20× higher channel count, and 11× reduced stiffness than conventional clinical electrodes. We validated our LCP-TF electrodes in multiple human intraoperative recording sessions and have disseminated this technology to >10 research groups. Using these arrays, we have observed high-frequency neural activity with sub-millimeter resolution.Significance.Our LCP-TF electrodes will advance human neuroscience research and improve clinical care by enabling broad access to transformative, high-resolution electrode arrays.

Autograft-derived spinal cord mass in the cervical spine following transplantation with olfactory mucosa cells for traumatic spinal cord injury: case report

This study describes a patient with an autograft-derived spinal cord mass following transplantation of olfactory mucosa for treatment of cervical spine injury. The authors report the case of a 35-year-old man who suffered a complete spinal cord injury (SCI) at C5-6 in 2001. The patient underwent an olfactory mucosal cell implantation at the location of injury 4 years following initial trauma. Twelve years later, the patient presented with rapidly progressive decline in upper-extremity function as well as neuropathic pain. Imaging revealed a heterogeneously enhancing intramedullary mass from C3 to C7. At surgery, the patient was found to have a posttransplant mucinous mass. Each mucinous cyst was drained and a portion of the cyst wall was removed. Histological examination demonstrated ciliated epithelium-lined fibrous tissue, submucosal glands, and mucoid material, consistent with a transplant-derived tumor. This case report both documents a rare long-term complication of olfactory mucosal cell transplantation and serves as a cautionary tale encouraging prudent use of novel treatments in a vulnerable population of patients with severe SCI.

Eosinophilic globules in a classic ependymoma: evidence of a possible secretory role

A number of neoplasms of the central nervous system can demonstrate diffuse eosinophilic globules, known to be secretory products of the corresponding cell type, but they have not been a salient feature in descriptions of classic ependymoma. Here, we present a case of a posterior fossa ependymoma demonstrating glassy PAS-positive, diastase-resistant, eosinophilic globules with light microscopic and ultrastructural features resembling Reissner fiber, the secretory product of the subcommissural organ. While there has been a single published description of an ependymoma with intra- and extracellular granulofibrillary material suggested to be evidence of secretory differentiation, ours is the first case to demonstrate diffuse eosinophilic globules in an ependymoma. The extent of globules allowed full study by electron microscopy to provide new insight into the secretory material and the surrounding structures. Our findings suggest that neoplastic ependymal cells can recapitulate the secretory capacity of the subcommissural organ.

History of awake mapping and speech and language localization: from modules to networks

Lesion-symptom correlations shaped the early understanding of cortical localization. The classic Broca-Wernicke model of cortical speech and language organization underwent a paradigm shift in large part due to advances in brain mapping techniques. This initially started by demonstrating that the cortex was excitable. Later, advancements in neuroanesthesia led to awake surgery for epilepsy focus and tumor resection, providing neurosurgeons with a means of studying cortical and subcortical pathways to understand neural architecture and obtain maximal resection while avoiding so-called critical structures. The aim of this historical review is to highlight the essential role of direct electrical stimulation and cortical-subcortical mapping and the advancements it has made to our understanding of speech and language cortical organization. Specifically, using cortical and subcortical mapping, neurosurgeons shifted from a localist view in which the brain is composed of rigid functional modules to one of dynamic and integrative large-scale networks consisting of interconnected cortical subregions.

Phase I trial of D2C7 immunotoxin (D2C7-IT) administered intratumorally via convection-enhanced delivery (CED) for recurrent malignant glioma (MG)

2566

Background: D2C7-IT is a recombinant immunotoxin comprised of a dual-specific antibody fragment targeting EGFRwt and EGFRvIII and a genetically engineered form of the Pseudomonas exotoxin, PE38-KDEL. We report the results of a phase I trial evaluating D2C7-IT delivered intratumorally by CED. Methods: Eligible patients were adults with recurrent supratentorial WHO grade III or IV MG; solitary tumor; ≥4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; and KPS>70%. Two patients per dose level (DL) were to enroll in the dose escalation portion (dose range: 40ng/mL to 23,354ng/mL). Results: From May 2015 to May 2018, 43 patients enrolled on study. Observed dose limiting toxicities include: grade 4 seizure (n=1) on DL3, grade 3 confusion and pyramidal tract syndrome (n=1) on DL13, and grade 4 cerebral edema (n=1) and grade 3 dysphasia (n=1) on DL17. Grade 3 or higher adverse events possibly related to D2C7-IT include: seizure (grade 4, n=2; grade 3, n=3), cerebral edema (grade 4, n=1), hydrocephalus (grade 3, n=5), headache (grade 3, n=4), hemiparesis (grade 3, n=4), dysphasia (grade 3, n=3), lymphopenia (grade 3, n=4), thromboembolic event (grade 3, n=3); and one each of grade 3 elevated ALT, urinary tract infection, fall, wound complication, generalized muscle weakness, confusion, encephalopathy, and somnolence. As of February 2020, four patients remain alive, with three patients demonstrating persistent radiographic partial response more than 54, 34 and 28 months after a single infusion of D2C7-IT. Conclusions: Dose level 13 (6,920ng/mL) was selected as the optimal phase II dose. Accrual in a dose expansion phase II trial is ongoing, and we are initiating a combination trial of D2C7-IT with checkpoint inhibitior. Clinical trial information: NCT02303678 .

Masson's tumor presenting as a left frontal intraparenchymal hemorrhage resulting in severe expressive aphasia during pregnancy: case report

Intravascular papillary endothelial hyperplasia (IPEH), commonly known as Masson's tumor, is a benign lesion that manifests as an excessive proliferation of endothelial cells within a vessel wall. IPEH is extremely rare in the brain, with only 36 intracranial cases previously described in the literature. It is commonly mistaken for more malignant pathologies, such as angiosarcoma. Careful histopathological examination is required for diagnosis, as no clinical or radiographic features are characteristic of this lesion. In this first published case of intracranial IPEH presenting during pregnancy, the authors describe a 32-year-old female with a left frontal intraparenchymal hemorrhage resulting in complete expressive aphasia at 28 weeks 6 days' gestation. An MRI scan obtained at a local hospital demonstrated an area of enhancement within the hemorrhage. The patient underwent a left frontoparietal craniotomy for hematoma evacuation and gross-total resection (GTR) of an underlying hemorrhagic mass at 29 weeks' gestation. This case illustrates the importance of multidisciplinary patient care and the feasibility of intervention in the early third trimester with subsequent term delivery. While GTR of IPEH is typically curative, the decision to proceed with surgical treatment of any intracranial lesion in pregnancy must balance maternal stability, gestational age, and suspected pathology.

Attitudes and opinions of US neurosurgical residents toward research and scholarship: a national survey

OBJECTIVE

The analysis of resident research productivity in neurosurgery has gained significant recent interest. Resident scholarly output affects departmental productivity, recruitment of future residents, and likelihood of future research careers. To maintain and improve opportunities for resident research, the authors evaluated factors that affect resident attitudes toward neurosurgical research on a national level.

METHODS

An online survey was distributed to all US neurosurgical residents. Questions assessed interest in research, perceived departmental support of research, and resident-perceived limitations in pursuing research. Residents were stratified based on number of publications above the median (AM; ≥ 14) or below the median (BM; < 14) for evaluation of factors influencing productivity.

RESULTS

A total of 278 resident responses from 82 US residency programs in 30 states were included (a 20% overall response rate). Residents predominantly desired future academic positions (53.2%), followed by private practice with some research (40.3%). Residents reported a mean ± SD of 11 ± 14 publications, which increased with postgraduate year level. The most common type of research involved retrospective cohort studies (24%) followed by laboratory/benchtop (19%) and case reports (18%). Residents as a group spent on average 14.1 ± 18.5 hours (median 7.0 hours) a week on research. Most residents (53.6%) had ≥ 12 months of protected research time. Mentorship (92.4%), research exposure (89.9%), and early interest in science (78.4%) had the greatest impact on interest in research while the most limiting factors were time (91.0%), call scheduling (47.1%), and funding/grants (37.1%). AM residents cited research exposure (p = 0.003), neurosurgery conference exposure (p = 0.02), formal research training prior to residency (p = 0.03), internal funding sources (p = 0.05), and software support (p = 0.02) as most important for their productivity. Moreover, more productive residents applied and received a higher number of < $10,000 and ≥ $10,000 grants (p < 0.05). A majority of residents (82.4%) agreed or strongly agreed with pursuing research throughout their professional careers. Overall, about half of residents (49.6%) were encouraged toward continued neurosurgical research, while the rest were neutral (36.7%) or discouraged (13.7%). Free-text responses helped to identify solutions on a departmental, regional, and national level that could increase interest in neurosurgical research.

CONCLUSIONS

This survey evaluates various factors affecting resident views toward research, which may also be seen in other specialties. Residents remain enthusiastic about neurosurgical research and offer several solutions to the ever-scarce commodities of time and funding within academic medicine.

Oncolytic polio/rhinovirus recombinant (PVSRIPO) against WHO grade IV malignant glioma (MG): Experience with retreatment of survivors from the phase I trial

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Background: We completed a study evaluating a single intratumoral delivery of PVSRIPO in recurrent WHO grade IV MG patients (N Engl J Med. 2018 Jul 12;379(2):150-161). Some patients who originally benefitted from the infusion of PVSRIPO demonstrated tumor recurrence, and we hypothesized that retreatment could trigger an immune recall effect, further extending their survival. We now report the impact of second and third intratumoral reinfusion of PVSRIPO in patients treated in the original dose finding study. Methods: Eligible patients were adults with recurrent supratentorial WHO grade IV MG who were experiencing disease recurrence after having benefitted from the first infusion of PVSRIPO. Additional eligibility criteria included: solitary tumor 1-5.5cm in diameter; ≥4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; KPS≥70%; and positive anti-polio titer. One patient each was retreated at 1 x 107 TCID50 and 1 x 1010 TCID50, and three patients were retreated on the identified phase 2 dose of 5 x 107 TCID50. Results: As of 2/09/2019, five patients have received a second intratumoral dose of PVSRIPO on study, one of which received a total of 3 doses. The patients who received two infusions of PVSRIPO were retreated 72 months, 43 months, 34 months, and 6 months after the first infusion. One additional patient received a second infusion of PVSRIPO 60 months after the first infusion and a third infusion of PVSRIPO 78 months after the first infusion. All patients demonstrated soap bubble degeneration on imaging, and two patients demonstrated tumor contraction. No grade 3 or higher adverse events related to PVSRIPO were observed after retreatment. Three of these patients remain alive more than 81, 80 and 52 months following the first PVSRIPO infusion and more than 9, 20 and 18 months after the second infusion, respectively. Two patients died 63 months and 20 months after the first infusion of PVSRIPO and 19.6 and 14 months after the second, respectively. The patient treated 3 times received the third infusion more than 2 months ago. Conclusions: Intratumoral reinfusion of PVSRIPO via CED is safe, and encouraging efficacy results have been observed. Clinical trial information: NCT01491893.

MTAP Loss Promotes Stemness in Glioblastoma and Confers Unique Susceptibility to Purine Starvation

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) is one of the most frequent genetic alterations in glioblastoma (GBM), but its pathologic consequences remain unclear. In this study, we report that loss of MTAP results in profound epigenetic reprogramming characterized by hypomethylation of PROM1/CD133-associated stem cell regulatory pathways. MTAP deficiency promotes glioma stem-like cell (GSC) formation with increased expression of PROM1/CD133 and enhanced tumorigenicity of GBM cells and is associated with poor prognosis in patients with GBM. As a combined consequence of purine production deficiency in MTAP-null GBM and the critical dependence of GSCs on purines, the enriched subset of CD133⁺ cells in MTAP-null GBM can be effectively depleted by inhibition of de novo purine synthesis. These findings suggest that MTAP loss promotes the pathogenesis of GBM by shaping the epigenetic landscape and stemness of GBM cells while simultaneously providing a unique opportunity for GBM therapeutics. SIGNIFICANCE: This study links the frequently mutated metabolic enzyme MTAP to dysregulated epigenetics and cancer cell stemness and establishes MTAP status as a factor for consideration in characterizing GBM and developing therapeutic strategies.

Single-institution retrospective review of patients with recurrent glioblastoma treated with bevacizumab in clinical practice

BACKGROUND AND AIMS

This retrospective review of patients with recurrent glioblastoma treated at the Preston Robert Tisch Brain Tumor Center investigated treatment patterns, survival, and safety with bevacizumab in a real-world setting.

METHODS

Adult patients with glioblastoma who initiated bevacizumab at disease progression between January 1, 2009, and May 14, 2012, were included. A Kaplan-Meier estimator was used to describe overall survival (OS), progression-free survival (PFS), and time to greater than or equal to 20% reduction in Karnofsky Performance Status (KPS). The effect of baseline demographic and clinical factors on survival was examined using a Cox proportional hazards model. Adverse event (AE) data were collected.

RESULTS

Seventy-four patients, with a median age of 59 years, were included in this cohort. Between bevacizumab initiation and first failure, defined as the first disease progression after bevacizumab initiation, biweekly bevacizumab and bevacizumab/irinotecan were the most frequently prescribed regimens. Median duration of bevacizumab treatment until failure was 6.4 months (range, 0.5-58.7). Median OS and PFS from bevacizumab initiation were 11.1 months (95% confidence interval [CI], 7.3-13.4) and 6.4 months (95% CI, 3.9-8.5), respectively. Median time to greater than or equal to 20% reduction in KPS was 29.3 months (95% CI, 13.8-∞). Lack of corticosteroid usage at the start of bevacizumab therapy was associated with both longer OS and PFS, with a median OS of 13.2 months (95% CI, 8.6-16.6) in patients who did not initially require corticosteroids versus 7.2 months (95% CI, 4.8-12.5) in those who did (P = 0.0382, log-rank), while median PFS values were 8.6 months (95% CI, 4.6-9.7) and 3.7 months (95% CI, 2.7-6.6), respectively (P = 0.0243, log-rank). Treatment failure occurred in 70 patients; 47 of whom received salvage therapy, and most frequently bevacizumab/carboplatin (7/47; 14.9%). Thirteen patients (18%) experienced a grade 3 AE of special interest for bevacizumab.

CONCLUSIONS

Treatment patterns and outcomes for patients with recurrent glioblastoma receiving bevacizumab in a real-world setting were comparable with those reported in prospective clinical trials.

MGMT: Immunohistochemical Detection in High-Grade Astrocytomas

Glioma therapeutic resistance to alkylating chemotherapy is mediated via O6-methylguanine-DNA methyltransferase (MGMT). We hypothesized that a CD45/HAM56/MGMT double-stained cocktail would improve MGMT discrimination in tumor cells versus inflammatory and endothelial cells (IEC). Total MGMT protein was quantified by IHC on 982 glioblastomas (GBM) and 199 anaplastic astrocytomas. Correcting for IEC was done by a CD45/HAM56/MGMT 2-color cocktail. Lowest IEC infiltrates (IEC "cold spots") were identified to quantitate MGMT as well as the percentage of IEC% in the IEC cold spots. MGMT promoter methylation (PM) was also determined. Among the GBM biopsies, mean uncorrected and corrected MGMT% were 19.87 (range 0-90) and 16.67; mean IEC% was 18.65 (range 1-80). Four hundred and fifty one (45.9%) GBM biopsies were positive MGMT PM. Both uncorrected and corrected MGMT% positivity correlated with PM. All 3 MGMT scores correlated with overall survival (OS) in GBM's. Cold spot IEC% was also positively associated with OS. These effects remained in a multivariate model after adjusting for age and disease status. Prognosis determined by correcting MGMT% score for IEC% is not improved in this analysis. However, IEC COLD SPOT score does provide additional prognostic information that can be gained from this correction method.

Recurrent Glioblastoma Treated with Recombinant Poliovirus

BACKGROUND

The prognosis of patients with recurrent World Health Organization (WHO) grade IV malignant glioma is dismal, and there is currently no effective therapy. We conducted a dose-finding and toxicity study in this population of patients, evaluating convection-enhanced, intratumoral delivery of the recombinant nonpathogenic polio-rhinovirus chimera (PVSRIPO). PVSRIPO recognizes the poliovirus receptor CD155, which is widely expressed in neoplastic cells of solid tumors and in major components of the tumor microenvironment.

METHODS

We enrolled consecutive adult patients who had recurrent supratentorial WHO grade IV malignant glioma, confirmed on histopathological testing, with measurable disease (contrast-enhancing tumor of ≥1 cm and ≤5.5 cm in the greatest dimension). The study evaluated seven doses, ranging between 10⁷ and 10¹⁰ 50% tissue-culture infectious doses (TCID₅₀), first in a dose-escalation phase and then in a dose-expansion phase.

RESULTS

From May 2012 through May 2017, a total of 61 patients were enrolled and received a dose of PVSRIPO. Dose level -1 (5.0×10⁷ TCID₅₀) was identified as the phase 2 dose. One dose-limiting toxic effect was observed; a patient in whom dose level 5 (10¹⁰ TCID₅₀) was administered had a grade 4 intracranial hemorrhage immediately after the catheter was removed. To mitigate locoregional inflammation of the infused tumor with prolonged glucocorticoid use, dose level 5 was deescalated to reach the phase 2 dose. In the dose-expansion phase, 19% of the patients had a PVSRIPO-related adverse event of grade 3 or higher. Overall survival among the patients who received PVSRIPO reached a plateau of 21% (95% confidence interval, 11 to 33) at 24 months that was sustained at 36 months.

CONCLUSIONS

Intratumoral infusion of PVSRIPO in patients with recurrent WHO grade IV malignant glioma confirmed the absence of neurovirulent potential. The survival rate among patients who received PVSRIPO immunotherapy was higher at 24 and 36 months than the rate among historical controls. (Funded by the Brain Tumor Research Charity and others; ClinicalTrials.gov number, NCT01491893 .).

The genomic landscape of TERT promoter wildtype-IDH wildtype glioblastoma

The majority of glioblastomas can be classified into molecular subgroups based on mutations in the TERT promoter (TERTp) and isocitrate dehydrogenase 1 or 2 (IDH). These molecular subgroups utilize distinct genetic mechanisms of telomere maintenance, either TERTp mutation leading to telomerase activation or ATRX-mutation leading to an alternative lengthening of telomeres phenotype (ALT). However, about 20% of glioblastomas lack alterations in TERTp and IDH. These tumors, designated TERTp^WT-IDH^WT glioblastomas, do not have well-established genetic biomarkers or defined mechanisms of telomere maintenance. Here we report the genetic landscape of TERTp^WT-IDH^WT glioblastoma and identify SMARCAL1 inactivating mutations as a novel genetic mechanism of ALT. Furthermore, we identify a novel mechanism of telomerase activation in glioblastomas that occurs via chromosomal rearrangements upstream of TERT. Collectively, our findings define novel molecular subgroups of glioblastoma, including a telomerase-positive subgroup driven by TERT-structural rearrangements (IDH^WT-TERT^SV), and an ALT-positive subgroup (IDH^WT-ALT) with mutations in ATRX or SMARCAL1.

Glioblastoma can be classified based on IDH and TERT promoter mutations, but ~20% of glioblastoma do not have these mutations (TERTp^WT-IDH^WT glioblastoma). Here, the authors present a genetic landscape of TERTp^WT-IDH^WT glioblastoma, identifying a telomerase-positive subgroup driven by TERT-structural rearrangements and an ALT-positive subgroup with mutations in ATRX or SMARCAL1.

Chemopotentiation by Ultrafractionated Radiotherapy in Glioblastoma Resistant to Conventional Therapy

Introduction

Induced radiation resistance (IRR) and hyper-radiosensitivity (HRS) are well-described phenomena in basic literature, yet few reports have been published in which such phenomena are exploited clinically for the benefit of patients. Glioblastoma is a prime example.

Case and methods

The case of an 82-year-old woman is described whose resected frontoparietal glioblastoma progressed through treatment administered according to standard methods. With review board and patient approval, we continued her treatment using radiotherapy and temozolomide, but drastically modified the radiotherapy fractionation, administering 50 cGy twice daily on each of the first 5 days of a 14-day cycle. Temozolomide was administered on the first 4 days of each cycle. We use the term “ultrafractionated radiotherapy” to refer to the extremely low doses of radiation used in this case.

Results

This modified regimen resulted in regression of the contrast-enhancing areas of disease recurrence identified on MRI, and the patient survived approximately 6 months following recurrence of her disease, having received 5 cycles of additional therapy after prior full-dose treatment.

Conclusions

Ultrafractionated radiotherapy and concurrent temozolomide were efficacious and tolerable in this patient whose glioblastoma previously progressed through conventional treatment. Additional studies of this approach are warranted. Free full text available at www.tumorionline.it

Dendritic Cells Enhance Polyfunctionality of Adoptively Transferred T Cells That Target Cytomegalovirus in Glioblastoma

Median survival for glioblastoma (GBM) remains <15 months. Human cytomegalovirus (CMV) antigens have been identified in GBM but not normal brain, providing an unparalleled opportunity to subvert CMV antigens as tumor-specific immunotherapy targets. A recent trial in recurrent GBM patients demonstrated the potential clinical benefit of adoptive T-cell therapy (ATCT) of CMV phosphoprotein 65 (pp65)-specific T cells. However, ex vivo analyses from this study found no change in the capacity of CMV pp65-specific T cells to gain multiple effector functions or polyfunctionality, which has been associated with superior antitumor efficacy. Previous studies have shown that dendritic cells (DC) could further enhance tumor-specific CD8+ T-cell polyfunctionality in vivo when administered as a vaccine. Therefore, we hypothesized that vaccination with CMV pp65 RNA-loaded DCs would enhance the frequency of polyfunctional CMV pp65-specific CD8+ T cells after ATCT. Here, we report prospective results of a pilot trial in which 22 patients with newly diagnosed GBM were initially enrolled, of which 17 patients were randomized to receive CMV pp65-specific T cells with CMV-DC vaccination (CMV-ATCT-DC) or saline (CMV-ATCT-saline). Patients who received CMV-ATCT-DC vaccination experienced a significant increase in the overall frequencies of IFNγ+, TNFα+, and CCL3+ polyfunctional, CMV-specific CD8+ T cells. These increases in polyfunctional CMV-specific CD8+ T cells correlated (R = 0.7371, P = 0.0369) with overall survival, although we cannot conclude this was causally related. Our data implicate polyfunctional T-cell responses as a potential biomarker for effective antitumor immunotherapy and support a formal assessment of this combination approach in a larger randomized study.Significance: A randomized pilot trial in patients with GBM implicates polyfunctional T-cell responses as a biomarker for effective antitumor immunotherapy. Cancer Res; 78(1); 256-64. ©2017 AACR.

Masson's tumor of the pineal region: case report

Intracranial intravascular papillary endothelial hyperplasia (IPEH), also referred to as Masson's tumor, is a condition that rarely occurs in the nervous system. IPEH most frequently occurs extracranially in the skin of the face, skull, neck, and trunk and can easily be mistaken clinically, radiologically, and histologically for angiosarcoma, organizing hematoma, or other vascular malformations. IPEH accounts for roughly 2% of all vascular tumors and is extremely rare intracranially, with only 23 reported cases compared with more than 300 cases of IPEH occurring in the skin and subcutaneous tissue. To date, it has never been reported to occur in the pineal region. The authors report the case of a patient with an IPEH in the pineal region who underwent complex resection and experienced reversal of neurological symptoms.

Phase 1 single-center, dose escalation study of D2C7-IT administered intratumorally via convection-enhanced delivery for adult patients with recurrent malignant glioma

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Background: D2C7 immunotoxin (D2C7-IT) is a dual-specific recombinant immunotoxin consisting of EGFR-wt and EGFRvIII monoclonal antibodies with a genetically engineered Pseudomonas exotoxin, PE-38KDEL. The primary objective is to determine the maximum tolerated dose of D2C7-IT when delivered intratumorally by convection enhanced delivery (CED). Methods: Inclusion criteria includes subjects with a single, recurrent supratentorial WHO grade III or IV glioma, KPS ≥ 70 and a washout of chemotherapy, bevacizumab or study drug of ≥ 4 weeks. Prior to administration of D2C7-IT, recurrent tumor must be confirmed by histopathology. A minimum of 2 subjects are accrued by dose level. Results: Currently, 23 subjects have been treated (16 male, 7 female) with a median age of 54 years. Out of 9 dose levels, 2 subjects have been treated at every dose except for 4 at dose level 3 (120 ng/ml) and 5 at dose 6 (405ng/ml). Adverse events possibly, probably or definitely related to D2C7-IT are mostly grade 1 or 2 events consisting of, but not limited to: intracranial hemorrhage (n = 1), stroke (n = 2), headache (n = 15), seizure (n = 5), confusion (n = 4), paresthesia (n = 4), dysarthria (n = 1), dysphasia (n = 4), visual disturbances (n = 7), fatigue (n = 4), gait disturbance (n = 2), elevated transaminases (n = 5), decreased platelets (n = 3), decreased neutrophil count (n = 1), nausea (n = 3), vomiting (n = 1), and thromboembolic event (n = 1). There was 1 dose limiting toxicity (grade 4 seizure at dose level 3), 2 grade 3 headaches and 1 grade 3 elevated ALT. 14 subjects are still alive with 6 remaining on study. So far, the longest survival time from infusion is 18.2+ months. Conclusions: D2C7-IT infusion via CED is safe with encouraging results. This dose escalation Phase I study is ongoing and will set the stage for the Phase II trial. Clinical trial information: NCT02303678.

Dose finding study of the intratumoral administration of the oncolytic polio/rhinovirus recombinant (PVSRIPO) against WHO grade IV malignant glioma (MG)

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Background: The live attenuated oral poliovirus vaccine was modified to contain a heterologous internal ribosomal entry site stemming from human rhinovirus type 2, creating PVSRIPO. PVSRIPO recognizes CD155, an oncofetal cell adhesion molecule and tumor antigen widely expressed ectopically in malignancy. We report results of the dose finding trial evaluating PVSRIPO delivered intratumorally by convection-enhanced delivery (CED). Methods: Eligible patients were adults with recurrent supratentorial WHO grade IV MG; solitary tumor 1-5.5cm in diameter; ≥4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; KPS≥70%; and positive anti-polio titer. The original two-step continual reassessment method dose escalation was amended to decrease to dose level(DL) -1 and DL -2 after observing prolonged steroid use in patients treated on higher DLs. Results: As of 2/01/2017, 52 pts were treated on study (1 each at DL1 and DL3, 7 at DL2, 2 at DL4, 4 at DL5, 24 at DL -1 and 13 at DL -2). Only one DLT was observed, a grade 4 intracranial hemorrhage at the time of catheter removal on DL5. Grade 3 or higher adverse events possibly, probably or definitely related to PVSRIPO include: lymphopenia (grade 3, n = 1), steroid myopathy (grade 3, n = 1), cerebral edema (grade 4, n = 1), headache (grade 3, n = 1), dystonia (grade 3, n = 1), pyramidal tract syndrome (grade 3, n = 6), seizure (grade 3, n = 1; grade 4, n = 1), delusions (grade 3, n = 1), hypertension (grade 3, n = 1), and thromboembolic events (grade 3, n = 2). At a median follow-up of 20.1 months, 20.8% of pts remain alive at 36-month post PVSRIPO infusion, compared to 4% of an historical control. Four pts remain alive more than 22 months post treatment without having received any additional intervention following PVSRIPO at 57.5+, 56.4+, 27.9+ and 23.2+ months. Conclusions: Infusion of PVSRIPO via CED is safe and encouraging efficacy results are observed. The dose finding study is now completed and we are initiating clinical trials evaluating combination of PVSRIPO with other therapies. Clinical trial information: NCT01491893.

Long-term Survival in Glioblastoma with Cytomegalovirus pp65-Targeted Vaccination

Purpose: Patients with glioblastoma have less than 15-month median survival despite surgical resection, high-dose radiation, and chemotherapy with temozolomide. We previously demonstrated that targeting cytomegalovirus pp65 using dendritic cells (DC) can extend survival and, in a separate study, that dose-intensified temozolomide (DI-TMZ) and adjuvant granulocyte macrophage colony-stimulating factor (GM-CSF) potentiate tumor-specific immune responses in patients with glioblastoma. Here, we evaluated pp65-specific cellular responses following DI-TMZ with pp65-DCs and determined the effects on long-term progression-free survival (PFS) and overall survival (OS).Experimental Design: Following standard-of-care, 11 patients with newly diagnosed glioblastoma received DI-TMZ (100 mg/m2/d × 21 days per cycle) with at least three vaccines of pp65 lysosome-associated membrane glycoprotein mRNA-pulsed DCs admixed with GM-CSF on day 23 ± 1 of each cycle. Thereafter, monthly DI-TMZ cycles and pp65-DCs were continued if patients had not progressed.Results: Following DI-TMZ cycle 1 and three doses of pp65-DCs, pp65 cellular responses significantly increased. After DI-TMZ, both the proportion and proliferation of regulatory T cells (Tregs) increased and remained elevated with serial DI-TMZ cycles. Median PFS and OS were 25.3 months [95% confidence interval (CI), 11.0-∞] and 41.1 months (95% CI, 21.6-∞), exceeding survival using recursive partitioning analysis and matched historical controls. Four patients remained progression-free at 59 to 64 months from diagnosis. No known prognostic factors [age, Karnofsky performance status (KPS), IDH-1/2 mutation, and MGMT promoter methylation] predicted more favorable outcomes for the patients in this cohort.Conclusions: Despite increased Treg proportions following DI-TMZ, patients receiving pp65-DCs showed long-term PFS and OS, confirming prior studies targeting cytomegalovirus in glioblastoma. Clin Cancer Res; 23(8); 1898-909. ©2017 AACR.

MiR-215 Is Induced Post-transcriptionally via HIF-Drosha Complex and Mediates Glioma-Initiating Cell Adaptation to Hypoxia by Targeting KDM1B

The hypoxic tumor microenvironment serves as a niche for maintaining the glioma-initiating cells (GICs) that are critical for glioblastoma (GBM) occurrence and recurrence. Here, we report that hypoxia-induced miR-215 is vital for reprograming GICs to fit the hypoxic microenvironment via suppressing the expression of an epigenetic regulator KDM1B and modulating activities of multiple pathways. Interestingly, biogenesis of miR-215 and several miRNAs is accelerated post-transcriptionally by hypoxia-inducible factors (HIFs) through HIF-Drosha interaction. Moreover, miR-215 expression correlates inversely with KDM1B while correlating positively with HIF1α and GBM progression in patients. These findings reveal a direct role of HIF in regulating miRNA biogenesis and consequently activating the miR-215-KDM1B-mediated signaling required for GIC adaptation to hypoxia.

Extradural Dermoid Cyst of the Anterior Infratemporal Fossa. Case Report

Dermoid cysts are rare in the skull base. There have been 10 reported cases of dermoid cysts in the cavernous sinus, two in the petrous apex, and one in the extradural Meckel cave. This is the first case report of a dermoid cyst in the anterior infratemporal fossa attached to the anterior dura of the foramen ovale. The clinical presentation, radiologic findings, histologic features, tumor origin, and operative technique are described along with a review of the literature.

Glioblastoma in the elderly: the effect of aggressive and modern therapies on survival

OBJECTIVE

The prognosis of elderly patients with glioblastoma (GBM) is universally poor. Currently, few studies have examined postoperative outcomes and the effects of various modern therapies such as bevacizumab on survival in this patient population. In this study, the authors evaluated the effects of various factors on overall survival in a cohort of elderly patients with newly diagnosed GBM.

METHODS

A retrospective review was performed of elderly patients (≥ 65 years old) with newly diagnosed GBM treated between 2004 and 2010. Various characteristics were evaluated in univariate and multivariate stepwise models to examine their effects on complication risk and overall survival.

RESULTS

A total of 120 patients were included in the study. The median age was 71 years, and sex was distributed evenly. Patients had a median Karnofsky Performance Scale (KPS) score of 80 and a median of 2 neurological symptoms on presentation. The majority (53.3%) of the patients did not have any comorbidities. Tumors most frequently (43.3%) involved the temporal lobe, followed by the parietal (35.8%), frontal (32.5%), and occipital (15.8%) regions. The majority (57.5%) of the tumors involved eloquent structures. The median tumor size was 4.3 cm. Every patient underwent resection, and 63.3% underwent gross-total resection (GTR). The vast majority (97.3%) of the patients received the postoperative standard of care consisting of radiotherapy with concurrent temozolomide. The majority (59.3%) of patients received additional agents, most commonly consisting of bevacizumab (38.9%). The median survival for all patients was 12.0 months; 26.7% of patients experienced long-term (≥ 2-year) survival. The extent of resection was seen to significantly affect overall survival; patients who underwent GTR had a median survival of 14.1 months, whereas those who underwent subtotal resection had a survival of 9.6 months (p = 0.038). Examination of chemotherapeutic effects revealed that the use of bevacizumab compared with no bevacizumab (20.1 vs 7.9 months, respectively; p < 0.0001) and irinotecan compared with no irinotecan (18.0 vs 9.7 months, respectively; p = 0.027) significantly improved survival. Multivariate stepwise analysis revealed that older age (hazard ratio [HR] 1.06 [95% CI1.02-1.10]; p = 0.0077), a higher KPS score (HR 0.97 [95% CI 0.95-0.99]; p = 0.0082), and the use of bevacizumab (HR 0.51 [95% CI 0.31-0.83]; p = 0.0067) to be significantly associated with survival.

CONCLUSION

This study has demonstrated that GTR confers a modest survival benefit on elderly patients with GBM, suggesting that safe maximal resection is warranted. In addition, bevacizumab significantly increased the overall survival of these elderly patients with GBM; older age and preoperative KPS score also were significant prognostic factors. Although elderly patients with GBM have a poor prognosis, they may experience enhanced survival after the administration of the standard of care and the use of additional chemotherapeutics such as bevacizumab.

Tetanus toxoid and CCL3 improve dendritic cell vaccines in mice and glioblastoma patients

Upon stimulation, dendritic cells (DCs) mature and migrate to draining lymph nodes to induce immune responses¹. As such, autologous DCs generated ex vivo have been pulsed with tumor antigens and injected back into patients as immunotherapy. While DC vaccines have shown limited promise in the treatment of patients with advanced cancers^2–4 including glioblastoma (GBM),^5–7 the factors dictating DC vaccine efficacy remain poorly understood. Here we demonstrate that pre-conditioning the vaccine site with a potent recall antigen such as tetanus/diphtheria (Td) toxoid can significantly improve the lymph node homing and efficacy of tumor antigen-specific DCs. To assess the impact of vaccine site pre-conditioning in humans, we randomized patients with GBM to pre-conditioning with mature DCs⁸ or Td unilaterally before bilateral vaccination with Cytomegalovirus pp65 RNA-pulsed DCs. We and other laboratories have shown that pp65 is expressed in > 90% of GBM specimens but not surrounding normal brain^9–12, providing an unparalleled opportunity to subvert this viral protein as a tumor-specific target. Patients given Td had enhanced DC migration bilaterally and significantly improved survival. In mice, Td pre-conditioning also enhanced bilateral DC migration and suppressed tumor growth in a manner dependent on the chemokine CCL3. Our clinical studies and corroborating investigations in mice suggest that pre-conditioning with a potent recall antigen may represent a viable strategy to improve antitumor immunotherapy.

Impact of Tumor Histology on Resectability and Neurological Outcome in Primary Intramedullary Spinal Cord Tumors

BACKGROUND:

Surgical outcomes for intramedullary spinal cord tumors are affected by many variables including tumor histology and preoperative neurological function.

OBJECTIVE:

To analyze the impact of tumor histology on neurological outcome in primary intramedullary spinal cord tumors.

METHODS:

A retrospective review of 102 consecutive patients with intramedullary spinal cord tumors treated at a single institution between January 1998 and March 2009.

RESULTS:

Ependymomas were the most common tumors with 55 (53.9%), followed by 21 astrocytomas (20.6%), 12 hemangioblastomas (11.8%), and 14 miscellaneous tumors (13.7%). Gross total resection was achieved in 50 ependymomas (90.9%), 3 astrocytomas (14.3%), 11 hemangioblastomas (91.7%), and 12 miscellaneous tumors (85.7%). At a mean follow-up of 41.8 months (range, 1-132 months), we observed recurrences in 4 ependymoma cases (7.3%), 10 astrocytoma cases (47.6%), 1 miscellaneous tumor case (7.1%), and no recurrence in hemangioblastoma cases. When analyzed by tumor location, there was no difference in neurological outcomes (P = .66). At the time of their last follow-up visit, 11 patients (20%) with an ependymoma improved, 38 (69%) remained the same, and 6 (10.9%) worsened. In patients with an astrocytoma, 1 (4.8%) improved, 10 (47.6%) remained the same, and 10 (47.6%) worsened. One patient (8.3%) with a hemangioblastoma improved and 11 (91.7%) remained the same. No patient with a hemangioblastoma worsened. In the miscellaneous tumor group, 2 (14.3%) improved, 10 (71.4%) remained the same, and 2 (14.3%) worsened. Preoperative neurological status (P = .02), tumor histology (P = .005), and extent of resection (P &lt; .0001) were all predictive of functional neurological outcomes.

CONCLUSION:

Tumor histology is the most important predictor of neurological outcome after surgical resection because it predicts resectability and recurrence.

Improved survival in the largest national cohort of adults with cerebellar versus supratentorial low-grade astrocytomas

OBJECT

Low-grade gliomas (LGGs) are indolent tumors that have the potential to dedifferentiate into malignant high-grade tumors. Recent studies have demonstrated that cerebellar low-grade tumors have a better prognosis than supratentorial tumors, although no study has focused on the risk factors for poor prognosis in cerebellar LGGs in adults. The authors of the current study aimed to address both of these concerns by using a large cohort derived from a national cancer registry and a smaller cohort derived from their institution's experience.

METHODS

Adults with diagnosed Grade I and Grade II gliomas of the cerebellum were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox proportional hazard models were used to predict rates of survival, and the log-rank test was applied to evaluate differences in Kaplan-Meier survival curves. An institutional cohort was created by isolating all patients whose surgical pathology revealed an LGG of the cerebellum. Excluded from analysis were patients in whom a glioma was first diagnosed under the age of 18 years and those whose tumors could not be definitively determined to arise from the cerebellum. Results Data from the local cohort (11 patients) demonstrated that the most common presenting symptom was headache, which occurred in more than 70% of the cohort. Approximately half of the patients in this cohort had symptomatic improvement after treatment.

RESULTS

from the SEER cohort (166 patients) revealed that adults with Grade I gliomas were slightly younger than those with Grade II tumors (p < 0.01), but no other demographic differences were observed. Patients with Grade I tumors were twice as likely to undergo gross-total resection (54% vs 21%), and those with Grade II gliomas were much more likely to receive postoperative radiation (3% vs 48%). Five-year survival was greater in the patients with Grade I gliomas than in those with Grade II lesions (91% vs 70%). Multivariate analysis revealed that an age ≥ 40 years (HR 7.30, 95% CI 3.55-15.0, p < 0.0001) and Grade II tumors (HR 2.76, 95% CI 1.12-6.84, p = 0.028) were risk factors for death, whereas female sex was protective (HR 0.28, 95% CI 0.14-0.59, p < 0.001). Log-rank tests revealed that a cerebellar location was protective (p < 0.0001), but this relationship was only true for Grade II tumors (p < 0.0001). Survival in patients with Grade I gliomas was not different based on the various lesion locations (p = 0.21).

CONCLUSIONS

Taken together, adults with cerebellar WHO Grade I and II astrocytomas have a much more favorable survival curve than those with similar supratentorial tumors. Research demonstrates that the primary driver of this phenomenon is the improved survival in patients with cerebellar Grade II gliomas.

Mutations in IDH1, IDH2, and in the TERT promoter define clinically distinct subgroups of adult malignant gliomas

Frequent mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) and the promoter of telomerase reverse transcriptase (TERT) represent two significant discoveries in glioma genomics. Understanding the degree to which these two mutations co-occur or occur exclusively of one another in glioma subtypes presents a unique opportunity to guide glioma classification and prognosis. We analyzed the relationship between overall survival (OS) and the presence of IDH1/2 and TERT promoter mutations in a panel of 473 adult gliomas. We hypothesized and show that genetic signatures capable of distinguishing among several types of gliomas could be established providing clinically relevant information that can serve as an adjunct to histopathological diagnosis. We found that mutations in the TERT promoter occurred in 74.2% of glioblastomas (GBM), but occurred in a minority of Grade II-III astrocytomas (18.2%). In contrast, IDH1/2 mutations were observed in 78.4% of Grade II-III astrocytomas, but were uncommon in primary GBM. In oligodendrogliomas, TERT promoter and IDH1/2 mutations co-occurred in 79% of cases. Patients whose Grade III-IV gliomas exhibit TERT promoter mutations alone predominately have primary GBMs associated with poor median OS (11.5 months). Patients whose Grade III-IV gliomas exhibit IDH1/2 mutations alone predominately have astrocytic morphologies and exhibit a median OS of 57 months while patients whose tumors exhibit both TERT promoter and IDH1/2 mutations predominately exhibit oligodendroglial morphologies and exhibit median OS of 125 months. Analyzing gliomas based on their genetic signatures allows for the stratification of these patients into distinct cohorts, with unique prognosis and survival.

The genetic landscape of anaplastic astrocytoma

Anaplastic astrocytoma WHO grade III (A3) is a lethal brain tumor that often occurs in middle aged patients. Clinically, it is challenging to distinguish A3 from glioblastoma multiforme (GBM) WHO grade IV. To reveal the genetic landscape of this tumor type, we sequenced the exome of a cohort of A3s (n=16). For comparison and to illuminate the genomic landscape of other glioma subtypes, we also included in our study diffuse astrocytoma WHO grade II (A2, n=7), oligoastrocytoma WHO grade II (OA2, n=2), anaplastic oligoastrocytoma WHO grade III (OA3, n=4), and GBM (n=28). Exome sequencing of A3s identified frequent mutations in IDH1 (75%, 12/16), ATRX (63%, 10/16), and TP53 (82%, 13/16). In contrast, the majority of GBMs (75%, 21/28) did not contain IDH1 or ATRX mutations, and displayed a distinct spectrum of mutations. Finally, our study also identified novel genes that were not previously linked to this tumor type. In particular, we found mutations in Notch pathway genes (NOTCH1, NOTCH2, NOTCH4, NOTCH2NL), including a recurrent NOTCH1-A465Tmutation, in 31% (5/16) of A3s. This study suggests genetic signatures will be useful for the classification of gliomas.