Transcriptomic observations of intra and extracellular immunotherapy targets for pediatric brain tumors.

OBJECTIVES: Despite surgical resection, chemoradiation, and targeted therapy, brain tumors remain a leading cause of cancer-related death in children. Immunotherapy has shown some promise and is actively being investigated for treating childhood brain tumors. However, a critical step in advancing immunotherapy for these patients is to uncover targets that can be effectively translated into therapeutic interventions. METHODS: In this study, our team performed a transcriptomic analysis across pediatric brain tumor types to identify potential targets for immunotherapy. Additionally, we assessed components that may impact patient response to immunotherapy, including the expression of genes essential for antigen processing and presentation, inhibitory ligands and receptors, interferon signature, and overall predicted T cell infiltration. RESULTS: We observed distinct expression patterns across tumor types. These included elevated expression of antigen genes and antigen processing machinery in some tumor types while other tumors had elevated inhibitory checkpoint receptors, known to be associated with response to checkpoint inhibitor immunotherapy. CONCLUSION: These findings suggest that pediatric brain tumors exhibit distinct potential for specific immunotherapies. We believe our findings can guide investigators in their assessment of appropriate immunotherapy classes and targets in pediatric brain tumors.

Infection rates during eras of intrathecal antibiotic use followed by antibiotic-impregnated catheter use in prevention of cerebrospinal fluid shunt infection.

OBJECTIVE: The Hydrocephalus Clinical Research Network (HCRN) implemented a perioperative infection prevention bundle for all CSF shunt surgeries in 2007 that included the relatively unproven technique of intrathecal instillation of the broad-spectrum antibiotics vancomycin and gentamicin into the shunt. In the meantime, the field debated the use of antibiotic-impregnated catheter (AIC) shunt tubing using clindamycin and rifampin, an increasingly widespread, but expensive and controversial, technique. It is unknown whether there were changes in infecting organisms associated with the use of these techniques during CSF shunt surgery at the hospital level. Key comparison periods include during the use of intrathecal antibiotics (period 1 from June 1, 2007, to December 31, 2011, at HCRN hospitals) and AIC (period 2 from January 1, 2012, to December 31, 2015, at HCRN as well as increasing over time at non-HCRN hospitals) and only standard use of routine prophylactic antibiotics (period 1 at non-HCRN hospitals). The aim of this study was to examine rates of CSF shunt surgery-related infections from 2007 to 2012 at the hospital level, including HCRN and non-HCRN hospitals, with a focus on infections with gram-negative organisms. METHODS: The authors conducted a retrospective observational cohort study at 6 children's hospitals with enrollment from 2007 to 2012 and surveillance through 2015. Bimonthly rates of shunt surgery-related infections were summarized to produce an overall hospital-specific time series, as well as by HCRN/non-HCRN status. An interrupted time series analysis was performed to assess the impact of change in HCRN perioperative infection prevention bundle on overall bimonthly infection rates. Quarterly rates of gram-negative shunt surgery-related infections were summarized to produce an overall hospital-specific time series. RESULTS: The overall bimonthly CSF shunt infection rate over time did not change significantly from 2007 to 2012. There was no difference in the trajectory of infection rates between HCRN and non-HCRN hospitals during the entire study period. No change in distributions of gram-negative organism infections was observed in hospitals from 2007 to 2015. CONCLUSIONS: There were no differences observed in hospital-level infection rates for low-risk patients undergoing CSF shunt surgery. This included analyses based on participation in the HCRN network, given their regular use of intrathecal antibiotics in period 1 and a focus on gram-negative infections with increasing adoption of AICs in period 2.

Immunotherapy for pediatric low-grade gliomas.

Pediatric low-grade gliomas (pLGGs) are the most common brain tumor types affecting children. Although gross-total resection remains the treatment of choice, many tumors are not amenable to complete removal, because they either involve midline structures, such as the optic chiasm or hypothalamus, and are not conducive to aggressive resection, or have diffuse biological features and blend with the surrounding brain. Historically, radiation therapy was used as the second-line option for disease control, but with the recognition that this often led to adverse long-term sequelae, particularly in young children, conventional chemotherapy assumed a greater role in initial therapy for unresectable tumors. A variety of agents demonstrated activity, but long-term disease control was suboptimal, with more than 50% of tumors exhibiting disease progression within 5 years. More recently, it has been recognized that a high percentage of these tumors in children exhibit constitutive activation of the mitogen-activated protein kinase (MAPK) pathway because of BRAF translocations or mutations, NFI mutations, or a host of other anomalies that converged on MAPK. This led to phase 1, 2, and 3 trials that explored the activity of blocking this signaling pathway, and the efficacy of this approach compared to conventional chemotherapy. Despite initial promise of these strategies, not all children tolerate this therapy, and many tumors resume growth once MAPK inhibition is stopped, raising concern that long-term and potentially life-long treatment will be required to maintain tumor control, even among responders. This observation has led to interest in other treatments, such as immunotherapy, that may delay or avoid the need for additional treatments. This chapter will summarize the place of immunotherapy in the current armamentarium for these tumors and discuss prior results and future options to improve disease control, with a focus on our prior efforts and experience in this field.

Antibiotic impregnated catheters and intrathecal antibiotics for CSF shunt infection prevention in children undergoing low-risk CSF shunt surgery.

BACKGROUND: Cerebrospinal fluid (CSF) shunts allow children with hydrocephalus to survive and avoid brain injury (J Neurosurg 107:345-57, 2007; Childs Nerv Syst 12:192-9, 1996). The Hydrocephalus Clinical Research Network implemented non-randomized quality improvement protocols that were shown to decrease infection rates compared to pre-operative prophylactic intravenous antibiotics alone (standard care): initially with intrathecal (IT) antibiotics between 2007-2009 (J Neurosurg Pediatr 8:22-9, 2011), followed by antibiotic impregnated catheters (AIC) in 2012-2013 (J Neurosurg Pediatr 17:391-6, 2016). No large scale studies have compared infection prevention between the techniques in children. Our objectives were to compare the risk of infection following the use of IT antibiotics, AIC, and standard care during low-risk CSF shunt surgery (i.e., initial CSF shunt placement and revisions) in children. METHODS: A retrospective observational cohort study at 6 tertiary care children's hospitals was conducted using Pediatric Health Information System + (PHIS +) data augmented with manual chart review. The study population included children ≤ 18 years who underwent initial shunt placement between 01/2007 and 12/2012. Infection and subsequent CSF shunt surgery data were collected through 12/2015. Propensity score adjustment for regression analysis was developed based on site, procedure type, and year; surgeon was treated as a random effect. RESULTS: A total of 1723 children underwent initial shunt placement between 2007-2012, with 1371 subsequent shunt revisions and 138 shunt infections. Propensity adjusted regression demonstrated no statistically significant difference in odds of shunt infection between IT antibiotics (OR 1.22, 95% CI 0.82-1.81, p = 0.3) and AICs (OR 0.91, 95% CI 0.56-1.49, p = 0.7) compared to standard care. CONCLUSION: In a large, observational multicenter cohort, IT antibiotics and AICs do not confer a statistically significant risk reduction compared to standard care for pediatric patients undergoing low-risk (i.e., initial or revision) shunt surgeries.

What to do with an incidental finding of a fused sagittal suture: a modified Delphi study.

OBJECTIVE: As many as 5% of normocephalic children may have a prematurely fused sagittal suture, yet the clinical significance and best course of management of this finding remain unclear. Providers in the Synostosis Research Group were surveyed to create a multicenter consensus on an optimal treatment and monitoring algorithm for this condition. METHODS: A four-round modified Delphi method was utilized. The first two rounds consisted of anonymous surveys distributed to 10 neurosurgeons and 9 plastic surgeons with expertise in craniosynostosis across 9 institutions, and presented 3 patients (aged 3 years, 2 years, and 2 months) with incidentally discovered fused sagittal sutures, normal cephalic indices, and no parietal dysmorphology. Surgeons were queried about their preferred term for this entity and how best to manage these patients. Results were synthesized to create a treatment algorithm. The third and fourth feedback rounds consisted of open discussion of the algorithm until no further concerns arose. RESULTS: Most surgeons preferred the term "premature fusion of the sagittal suture" (93%). At the conclusion of the final round, all surgeons agreed to not operate on the 3- and 2-year-old patients unless symptoms of intracranial hypertension or papilledema were present. In contrast, 50% preferred to operate on the 2-month-old. However, all agreed to utilize shared decision-making, taking into account any concerns about future head shape and neurodevelopment. Panelists agreed that patients over 18 months of age without signs or symptoms suggesting elevated intracranial pressure (ICP) should not undergo surgical treatment. CONCLUSIONS: Through the Delphi method, a consensus regarding management of premature fusion of the sagittal suture was obtained from a panel of North American craniofacial surgeons. Without signs or symptoms of ICP elevation, surgery is not recommended in patients over 18 months of age. However, for children younger than 18 months, surgery should be discussed with caregivers using a shared decision-making process.

Vorinostat, temozolomide or bevacizumab with irradiation and maintenance BEV/TMZ in pediatric high-grade glioma: A Children's Oncology Group Study.

Background: Outcomes for children with high-grade gliomas (HGG) remain poor. This multicenter phase II trial evaluated whether concurrent use of vorinostat or bevacizumab with focal radiotherapy (RT) improved 1-year event-free survival (EFS) compared to temozolomide in children with newly diagnosed HGG who received maintenance temozolomide and bevacizumab. Methods: Patients ≥ 3 and < 22 years with localized, non-brainstem HGG were randomized to receive RT (dose 54-59.4Gy) with vorinostat, temozolomide, or bevacizumab followed by 12 cycles of bevacizumab and temozolomide maintenance therapy. Results: Among 90 patients randomized, the 1-year EFS for concurrent bevacizumab, vorinostat, or temozolomide with RT was 43.8% (±8.8%), 41.4% (±9.2%), and 59.3% (±9.5%), respectively, with no significant difference among treatment arms. Three- and five-year EFS for the entire cohort was 14.8% and 13.4%, respectively, with no significant EFS difference among the chemoradiotherapy arms. IDH mutations were associated with more favorable EFS (P = .03), whereas H3.3 K27M mutations (P = .0045) and alterations in PIK3CA or PTEN (P = .025) were associated with worse outcomes. Patients with telomerase- and alternative lengthening of telomeres (ALT)-negative tumors (n = 4) had an EFS of 100%, significantly greater than those with ALT or telomerase, or both (P = .002). While there was no difference in outcomes based on TERT expression, high TERC expression was associated with inferior survival independent of the telomere maintenance mechanism (P = .0012). Conclusions: Chemoradiotherapy with vorinostat or bevacizumab is not superior to temozolomide in children with newly diagnosed HGG. Patients with telomerase- and ALT-negative tumors had higher EFS suggesting that, if reproduced, mechanism of telomere maintenance should be considered in molecular-risk stratification in future studies.

Utilization trends in cerebrospinal fluid shunt infection prevention techniques in the United States from 2007 to 2015.

OBJECTIVE: The objective of this study was to describe trends in the utilization of infection prevention techniques (standard care, intrathecal [IT] antibiotics, antibiotic-impregnated catheters [AICs], and combination of IT antibiotics and AICs) among participating hospitals over time. METHODS: This retrospective cohort study at six large children's hospitals between 2007 and 2015 included children ≤ 18 years of age who underwent initial shunt placement between 2007 and 2012. Pediatric Health Information System + (PHIS+) data were augmented with chart review data for all shunt surgeries that occurred prior to the first shunt infection. The Pearson chi-square test was used to test for differences in outcomes. RESULTS: In total, 1723 eligible children had initial shunt placement between 2007 and 2012, with 3094 shunt surgeries through 2015. Differences were noted between hospitals in gestational age, etiology of hydrocephalus, and race and ethnicity, but not sex, weight at surgery, and previous surgeries. Utilization of infection prevention techniques varied across participating hospitals. Hydrocephalus Clinical Research Network hospitals used more IT antibiotics in 2007-2011; after 2012, increasing adoption of AICs was observed in most hospitals. CONCLUSIONS: A consistent trend of decreasing IT antibiotic use and increased AIC utilization was observed after 2012, except for hospital B, which consistently used AICs.

Characterization of low-grade epilepsy-associated tumor from implanted stereoelectroencephalography electrodes.

Low-grade epilepsy-associated tumors (LEATs) are a common cause of drug-resistant epilepsy in children. Herein, we demonstrate the feasibility of using tumor tissue derived from stereoelectroencephalography (sEEG) electrodes upon removal to molecularly characterize tumors and aid in diagnosis. An 18-year-old male with focal epilepsy and MRI suggestive of a dysembryoplastic neuroepithelial tumor (DNET) in the left posterior temporal lobe underwent implantation of seven peri-tumoral sEEG electrodes for peri-operative language mapping and demarcation of the peri-tumoral ictal zone prior to DNET resection. Using electrodes that passed through tumor tissue, we show successful isolation of tumor DNA and subsequent analysis using standard methods for tumor classification by DNA, including Glioseq targeted sequencing and DNA methylation array analysis. This study provides preliminary evidence for the feasibility of molecular diagnosis of LEATs or other lesions using a minimally invasive method with microscopic tissue volumes. The implications of sEEG electrodes in tumor characterization are broad but would aid in diagnosis and subsequent targeted therapeutic strategies.

An ERK5-PFKFB3 axis regulates glycolysis and represents a therapeutic vulnerability in pediatric diffuse midline glioma.

Metabolic reprogramming in pediatric diffuse midline glioma is driven by gene expression changes induced by the hallmark histone mutation H3K27M, which results in aberrantly permissive activation of oncogenic signaling pathways. Previous studies of diffuse midline glioma with altered H3K27 (DMG-H3K27a) have shown that the RAS pathway, specifically through its downstream kinase, extracellular-signal-related kinase 5 (ERK5), is critical for tumor growth. Further downstream effectors of ERK5 and their role in DMG-H3K27a metabolic reprogramming have not been explored. We establish that ERK5 is a critical regulator of cell proliferation and glycolysis in DMG-H3K27a. We demonstrate that ERK5 mediates glycolysis through activation of transcription factor MEF2A, which subsequently modulates expression of glycolytic enzyme PFKFB3. We show that in vitro and mouse models of DMG-H3K27a are sensitive to the loss of PFKFB3. Multi-targeted drug therapy against the ERK5-PFKFB3 axis, such as with small-molecule inhibitors, may represent a promising therapeutic approach in patients with pediatric diffuse midline glioma.

A multi-institutional pediatric dataset of clinical radiology MRIs by the Children's Brain Tumor Network.

Pediatric brain and spinal cancers remain the leading cause of cancer-related death in children. Advancements in clinical decision-support in pediatric neuro-oncology utilizing the wealth of radiology imaging data collected through standard care, however, has significantly lagged other domains. Such data is ripe for use with predictive analytics such as artificial intelligence (AI) methods, which require large datasets. To address this unmet need, we provide a multi-institutional, large-scale pediatric dataset of 23,101 multi-parametric MRI exams acquired through routine care for 1,526 brain tumor patients, as part of the Children's Brain Tumor Network. This includes longitudinal MRIs across various cancer diagnoses, with associated patient-level clinical information, digital pathology slides, as well as tissue genotype and omics data. To facilitate downstream analysis, treatment-naïve images for 370 subjects were processed and released through the NCI Childhood Cancer Data Initiative via the Cancer Data Service. Through ongoing efforts to continuously build these imaging repositories, our aim is to accelerate discovery and translational AI models with real-world data, to ultimately empower precision medicine for children.

Associations of Standard Care, Intrathecal Antibiotics, and Antibiotic-Impregnated Catheters With Cerebrospinal Fluid Shunt Infection Organisms and Resistance.

BACKGROUND: Infection prevention techniques used during cerebrospinal fluid (CSF) shunt surgery include: (1) standard perioperative intravenous antibiotics, (2) intrathecal (IT) antibiotics, (3) antibiotic-impregnated catheter (AIC) shunt tubing, or (4) Both IT and AIC. These techniques have not been assessed against one another for their impact on the infecting organisms and patterns of antimicrobial resistance. METHODS: We performed a retrospective longitudinal observational cohort study of children with initial CSF shunt placement between January 2007 and December 2012 at 6 US hospitals. Data were collected electronically from the Pediatric Health Information Systems+ (PHIS+) database, and augmented with standardized chart review. Only subjects with positive CSF cultures were included in this study. RESULTS: Of 1,723 children whose initial shunt placement occurred during the study period, 196 (11%) developed infection, with 157 (80%) having positive CSF cultures. Of these 157 subjects, 69 (44%) received standard care, 28 (18%) received AIC, 55 (35%) received IT antibiotics, and 5 (3%) received Both at the preceding surgery. The most common organisms involved in monomicrobial infections were Staphylococcus aureus (38, 24%), coagulase-negative staphylococci (36, 23%), and Cutibacterium acnes (6, 4%). Compared with standard care, the other infection prevention techniques were not significantly associated with changes to infecting organisms; AIC was associated with decreased odds of methicillin resistance among coagulase-negative staphylococci. CONCLUSIONS: Because no association was found between infection prevention technique and infecting organisms when compared to standard care, other considerations such as tolerability, availability, and cost should inform decisions about infection prevention during CSF shunt placement surgery.

Immuno-PET Imaging of CD69 Visualizes T-Cell Activation and Predicts Survival Following Immunotherapy in Murine Glioblastoma.

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. Immunotherapy may be promising for the treatment of some patients with GBM; however, there is a need for noninvasive neuroimaging techniques to predict immunotherapeutic responses. The effectiveness of most immunotherapeutic strategies requires T-cell activation. Therefore, we aimed to evaluate an early marker of T-cell activation, CD69, for its use as an imaging biomarker of response to immunotherapy for GBM. Herein, we performed CD69 immunostaining on human and mouse T cells following in vitro activation and post immune checkpoint inhibitors (ICI) in an orthotopic syngeneic mouse glioma model. CD69 expression on tumor-infiltrating leukocytes was assessed using single-cell RNA sequencing (scRNA-seq) data from patients with recurrent GBM receiving ICI. Radiolabeled CD69 Ab PET/CT imaging (CD69 immuno-PET) was performed on GBM-bearing mice longitudinally to quantify CD69 and its association with survival following immunotherapy. We show CD69 expression is upregulated upon T-cell activation and on tumor-infiltrating lymphocytes (TIL) in response to immunotherapy. Similarly, scRNA-seq data demonstrated elevated CD69 on TILs from patients with ICI-treated recurrent GBM as compared with TILs from control cohorts. CD69 immuno-PET studies showed a significantly higher tracer uptake in the tumors of ICI-treated mice compared with controls. Importantly, we observed a positive correlation between survival and CD69 immuno-PET signals in immunotherapy-treated animals and established a trajectory of T-cell activation by virtue of CD69-immuno-PET measurements. Our study supports the potential use of CD69 immuno-PET as an immunotherapy response assessment imaging tool for patients with GBM. Significance: Immunotherapy may hold promise for the treatment of some patients with GBM. There is a need to assess therapy responsiveness to allow the continuation of effective treatment in responders and to avoid ineffective treatment with potential adverse effects in the nonresponders. We demonstrate that noninvasive PET/CT imaging of CD69 may allow early detection of immunotherapy responsiveness in patients with GBM.

Comparison of outcomes in the management of abdominal pseudocyst in children with shunted hydrocephalus: a Hydrocephalus Clinical Research Network study.

OBJECTIVE: Abdominal pseudocyst (APC) can cause distal site failure in children with ventriculoperitoneal shunts and is specifically designated as an infection in Hydrocephalus Clinical Research Network (HCRN) protocols. Specific management and outcomes of children with APCs have not been reported in a multicenter study. In this study, the authors investigated the management and outcomes of APC in children with shunted hydrocephalus who were treated at centers in the HCRN. METHODS: The HCRN Registry was queried to identify children < 18 years old with shunts who were diagnosed with an APC (i.e., a loculated abdominal fluid collection containing the peritoneal catheter with abdominal distention and/or displacement of peritoneal contents). The primary outcome was shunt failure after APC treatment. The primary variable was reimplantation of the distal catheter after pseudocyst treatment back into the peritoneum versus implantation in a nonperitoneal site. Other risk factors for shunt failure after APC treatment and variability in APC management were investigated. RESULTS: Among 141 children from 14 centers who underwent first-time management of an APC over a 14-year period, the median time from previous shunt surgery to APC diagnosis was 3.8 months. Overall, 17.7% of children had a positive culture: APC cultures were positive in 14.2% and CSF cultures in 15.6%. Six other children underwent shunt revision without removal; all underwent reoperation within 1 month. There was no difference in shunt survival (log-rank test, p = 0.42) or number of subsequent revisions within 6, 12, or 24 months for shunts reimplanted in the abdomen versus those implanted in a nonperitoneal location. Nonperitoneal implantation was associated with more noninfectious revisions (42.3% vs 22.9%, p = 0.019), whereas infection was more common after reimplantation in the abdomen (25.7% vs 7.0%, p = 0.003). Univariable analysis demonstrated that younger age at APC diagnosis (8.3 vs 12.2 years, p = 0.006) and prior shunt procedure within 12 weeks of APC diagnosis (59.5% vs 40.5%, p = 0.012) were associated with shunt failure after APC treatment. Multivariable modeling confirmed that prior shunt surgery within 12 weeks of APC diagnosis was independently associated with failure (HR 1.79 [95% CI 1.04-3.07], p = 0.035). CONCLUSIONS: In the HCRN, APCs in the setting of CSF shunts are usually managed with externalization. Shunt surgery within 12 weeks of APC diagnosis was associated with risk of failure after APC treatment. Although no differences were found in overall shunt failure rate, noninfectious shunt revisions were more common in the nonperitoneal distal catheter sites, and infection was a more common reason for failure after reimplantation of the shunt in the abdomen.

Treatment of hydrocephalus following posterior fossa tumor resection: a multicenter collaboration from the Hydrocephalus Clinical Research Network.

OBJECTIVE: Persistent hydrocephalus following posterior fossa brain tumor (PFBT) resection is a common cause of morbidity in pediatric brain tumor patients, for which the optimal treatment is debated. The purpose of this study was to compare treatment outcomes between VPS and ETV in patients with persistent hydrocephalus following surgical resection of a PFBT. METHODS: A post-hoc analysis was performed of the Hydrocephalus Clinical Research Network (HCRN) prospective observational study evaluating VPS and ETV for pediatric patients. Children who experienced hydrocephalus secondary to PFBT from 2008 to 2021 were included. Primary outcomes were VPS/ETV treatment failure and time-to-failure (TTF). RESULTS: Among 241 patients, the VPS (183) and ETV (58) groups were similar in age, extent of tumor resection, and preoperative ETV Success Score. There was no difference in overall treatment failure between VPS and ETV (33.9% vs 31.0%, p = 0.751). However, mean TTF was shorter for ETV than VPS (0.45 years vs 1.30 years, p = 0.001). While major complication profiles were similar, compared to VPS, ETV patients had relatively higher incidence of minor CSF leak (10.3% vs. 1.1%, p = 0.003) and pseudomeningocele (12.1% vs 3.3%, p = 0.02). No ETV failures were identified beyond 3 years, while shunt failures occurred beyond 5 years. Shunt infections occurred in 5.5% of the VPS cohort. CONCLUSIONS: ETV and VPS offer similar overall success rates for PFBT-related postoperative hydrocephalus. ETV failure occurs earlier, while susceptibility to VPS failure persists beyond 5 years. Tumor histology and grade may be considered when selecting the optimal means of CSF diversion.

Targeting mitochondrial energetics reverses panobinostat- and marizomib-induced resistance in pediatric and adult high-grade gliomas.

In previous studies, we demonstrated that panobinostat, a histone deacetylase inhibitor, and bortezomib, a proteasomal inhibitor, displayed synergistic therapeutic activity against pediatric and adult high-grade gliomas. Despite the remarkable initial response to this combination, resistance emerged. Here, in this study, we aimed to investigate the molecular mechanisms underlying the anticancer effects of panobinostat and marizomib, a brain-penetrant proteasomal inhibitor, and the potential for exploitable vulnerabilities associated with acquired resistance. RNA sequencing followed by gene set enrichment analysis (GSEA) was employed to compare the molecular signatures enriched in resistant compared with drug-naïve cells. The levels of adenosine 5'-triphosphate (ATP), nicotinamide adenine dinucleotide (NAD)+ content, hexokinase activity, and tricarboxylic acid (TCA) cycle metabolites required for oxidative phosphorylation to meet their bioenergetic needs were analyzed. Here, we report that panobinostat and marizomib significantly depleted ATP and NAD+ content, increased mitochondrial permeability and reactive oxygen species generation, and promoted apoptosis in pediatric and adult glioma cell lines at initial treatment. However, resistant cells exhibited increased levels of TCA cycle metabolites, which required for oxidative phosphorylation to meet their bioenergetic needs. Therefore, we targeted glycolysis and the electron transport chain (ETC) with small molecule inhibitors, which displayed substantial efficacy, suggesting that resistant cell survival is dependent on glycolytic and ETC complexes. To verify these observations in vivo, lonidamine, an inhibitor of glycolysis and mitochondrial function, was chosen. We produced two diffuse intrinsic pontine glioma (DIPG) models, and lonidamine treatment significantly increased median survival in both models, with particularly dramatic effects in panobinostat- and marizomib-resistant cells. These data provide new insights into mechanisms of treatment resistance in gliomas.

A neurodevelopmental epigenetic programme mediated by SMARCD3-DAB1-Reelin signalling is hijacked to promote medulloblastoma metastasis.

How abnormal neurodevelopment relates to the tumour aggressiveness of medulloblastoma (MB), the most common type of embryonal tumour, remains elusive. Here we uncover a neurodevelopmental epigenomic programme that is hijacked to induce MB metastatic dissemination. Unsupervised analyses of integrated publicly available datasets with our newly generated data reveal that SMARCD3 (also known as BAF60C) regulates Disabled 1 (DAB1)-mediated Reelin signalling in Purkinje cell migration and MB metastasis by orchestrating cis-regulatory elements at the DAB1 locus. We further identify that a core set of transcription factors, enhancer of zeste homologue 2 (EZH2) and nuclear factor I X (NFIX), coordinates with the cis-regulatory elements at the SMARCD3 locus to form a chromatin hub to control SMARCD3 expression in the developing cerebellum and in metastatic MB. Increased SMARCD3 expression activates Reelin-DAB1-mediated Src kinase signalling, which results in a MB response to Src inhibition. These data deepen our understanding of how neurodevelopmental programming influences disease progression and provide a potential therapeutic option for patients with MB.

The children's brain tumor network (CBTN) - Accelerating research in pediatric central nervous system tumors through collaboration and open science.

Pediatric brain tumors are the leading cause of cancer-related death in children in the United States and contribute a disproportionate number of potential years of life lost compared to adult cancers. Moreover, survivors frequently suffer long-term side effects, including secondary cancers. The Children's Brain Tumor Network (CBTN) is a multi-institutional international clinical research consortium created to advance therapeutic development through the collection and rapid distribution of biospecimens and data via open-science research platforms for real-time access and use by the global research community. The CBTN's 32 member institutions utilize a shared regulatory governance architecture at the Children's Hospital of Philadelphia to accelerate and maximize the use of biospecimens and data. As of August 2022, CBTN has enrolled over 4700 subjects, over 1500 parents, and collected over 65,000 biospecimen aliquots for research. Additionally, over 80 preclinical models have been developed from collected tumors. Multi-omic data for over 1000 tumors and germline material are currently available with data generation for > 5000 samples underway. To our knowledge, CBTN provides the largest open-access pediatric brain tumor multi-omic dataset annotated with longitudinal clinical and outcome data, imaging, associated biospecimens, child-parent genomic pedigrees, and in vivo and in vitro preclinical models. Empowered by NIH-supported platforms such as the Kids First Data Resource and the Childhood Cancer Data Initiative, the CBTN continues to expand the resources needed for scientists to accelerate translational impact for improved outcomes and quality of life for children with brain and spinal cord tumors.

Magnetic Resonance Spectroscopy Metabolites as Biomarkers of Disease Status in Pediatric Diffuse Intrinsic Pontine Gliomas (DIPG) Treated with Glioma-Associated Antigen Peptide Vaccines.

PURPOSE: Diffuse intrinsic pontine gliomas (DIPG) are highly aggressive tumors with no currently available curative therapy. This study evaluated whether measurements of in vivo cell metabolites using magnetic resonance spectroscopy (MRS) may serve as biomarkers of response to therapy, including progression. METHODS: Single-voxel MR spectra were serially acquired in two cohorts of patients with DIPG treated with radiation therapy (RT) with or without concurrent chemotherapy and prior to progression: 14 participants were enrolled in a clinical trial of adjuvant glioma-associated antigen peptide vaccines and 32 patients were enrolled who did not receive adjuvant vaccine therapy. Spearman correlations measured overall survival associations with absolute metabolite concentrations of myo-inositol (mI), creatine (Cr), and n-acetyl-aspartate (NAA) and their ratios relative to choline (Cho) during three specified time periods following completion of RT. Linear mixed-effects regression models evaluated the longitudinal associations between metabolite ratios and time from death (terminal decline). RESULTS: Overall survival was not associated with metabolite ratios obtained shortly after RT (1.9-3.8 months post-diagnosis) in either cohort. In the vaccine cohort, an elevated mI/Cho ratio after 2-3 doses (3.9-5.2 months post-diagnosis) was associated with longer survival (rho = 0.92, 95% CI 0.67-0.98). Scans performed up to 6 months before death showed a terminal decline in the mI/Cho ratio, with an average of 0.37 ratio/month in vaccine patients (95% CI 0.11-0.63) and 0.26 (0.04-0.48) in the non-vaccine cohort. CONCLUSION: Higher mI/Cho ratios following RT, consistent with less proliferate tumors and decreased cell turnover, were associated with longer survival, suggesting that this ratio can serve as a biomarker of prognosis following RT. This finding was seen in both cohorts, although the association with OS was detected earlier in the vaccine cohort. Increased mI/Cho (possibly reflecting immune-effector cell influx into the tumor as a mechanism of tumor response) requires further study.

A multi-institutional survey on calvarial vault remodeling techniques for sagittal synostosis and outcomes analysis for patients treated at 12 months and older.

OBJECTIVE: Surgical treatment of sagittal craniosynostosis is challenging in older patients. This study aimed to assess the effect of increasing age on open surgical technique selection and patient outcomes using the multi-institutional Synostosis Research Group (SynRG) collaboration. METHODS: Surgeons in SynRG were surveyed for key influences on their preferred open calvarial vault remodeling techniques at various patient ages: < 6, 6-12, and > 12 months. The SynRG database was then queried for open repairs of nonsyndromic sagittal craniosynostosis performed for patients older than 12 months of age. Perioperative measures, complications, and preoperative and postoperative cephalic indices were reviewed. RESULTS: All surgeons preferred to treat patients at an earlier age, and most (89%) believed that less-optimal outcomes were achieved at ages older than 12 months. The modified pi procedure was the dominant technique in those younger than 12 months, while more involved open surgical techniques were performed for older patients, with a wide variety of open calvarial vault remodeling techniques used. Forty-four patients met inclusion criteria, with a mean (± SD) age at surgery of 29 ± 16 months. Eleven patients underwent parietal reshaping, 10 parietal-occipital switch, 9 clamshell craniotomy, 7 geometric parietal expansion, 6 modified pi procedure, and 1 parietal distraction. There were no readmissions, complications, or mortality within 30 days postoperatively. Patients' cephalic indices improved a mean of 6.4% ± 4.0%, with a mean postoperative cephalic index of 74.2% ± 4.9%. Differences in postoperative cephalic index (p < 0.04) and hospital length of stay (p = 0.01) were significant between technique cohorts. Post hoc Tukey-Kramer analysis identified the parietal reshaping technique as being significantly associated with a reduced hospital length of stay. CONCLUSIONS: Patient age is an important driver in technique selection, with surgeons selecting a more involved calvarial vault remodeling technique in older children. A variety of surgical techniques were analyzed, with the parietal reshaping technique being significantly associated with reduced length of stay; however, multiple perioperative factors may be contributory and require further analysis. When performed at high-volume centers by experienced pediatric neurosurgeons and craniofacial surgeons, open calvarial vault techniques can be a safe method for treating sagittal craniosynostosis in older children.

Hydrocephalus surveillance following CSF diversion: a modified Delphi study.

OBJECTIVE: Long-term follow-up is often recommended for patients with hydrocephalus, but the frequency of clinical follow-up, timing and modality of imaging, and duration of surveillance have not been clearly defined. Here, the authors used the modified Delphi method to identify areas of consensus regarding the modality, frequency, and duration of hydrocephalus surveillance following surgical treatment. METHODS: Pediatric neurosurgeons serving as institutional liaisons to the Hydrocephalus Clinical Research Network (HCRN), or its implementation/quality improvement arm (HCRNq), were invited to participate in this modified Delphi study. Thirty-seven consensus statements were generated and distributed via an anonymous electronic survey, with responses structured as a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). A subsequent, virtual meeting offered the opportunity for open discussion and modification of the statements in an effort to reach consensus (defined as ≥ 80% agreement or disagreement). RESULTS: Nineteen pediatric neurosurgeons participated in the first round, after which 15 statements reached consensus. During the second round, 14 participants met virtually for review and discussion. Some statements were modified and 2 statements were combined, resulting in a total of 36 statements. At the conclusion of the session, consensus was achieved for 17 statements regarding the following: 1) the role of standardization; 2) preferred imaging modalities; 3) postoperative follow-up after shunt surgery (subdivided into immediate postoperative imaging, delayed postoperative imaging, routine clinical surveillance, and routine radiological surveillance); and 4) postoperative follow-up after an endoscopic third ventriculostomy. Consensus could not be achieved for 19 statements. CONCLUSIONS: Using the modified Delphi method, 17 consensus statements were developed with respect to both clinical and radiological follow-up after a shunt or endoscopic third ventriculostomy. The frequency, modality, and duration of surveillance were addressed, highlighting areas in which no clear data exist to guide clinical practice. Although further studies are needed to evaluate the clinical utility and cost-effectiveness of hydrocephalus surveillance, the current study provides a framework to guide future efforts to develop standardized clinical protocols for the postoperative surveillance of patients with hydrocephalus. Ultimately, the standardization of hydrocephalus surveillance has the potential to improve patient care as well as optimize the use of healthcare resources.