New CNS tumor classification: The importance in pediatric neurosurgical practice.

Background: The management of the central nervous system (CNS) tumors in the pediatric population is crucial in neurosurgical practice. The World Health Organization (WHO) has evolved its classification of CNS tumors from the 19th century to the 5th edition, published in 2021, incorporating molecular advancements. This transition from morphology to molecular characterization is ongoing. Methods: This manuscript analyzes the modifications introduced in the 5th edition of WHO's CNS tumor classification, particularly focusing on pediatric tumor families. The paper integrates clinical, morphological, and molecular information, aiming to guide pediatric neurosurgeons in their daily practice and interdisciplinary discussions. Results: The 5th edition of the WHO classification introduces a hybrid taxonomy that incorporates both molecular and histological components. The terminology shifts from "entity" to "type" and "subtype," aiming to standardize terminology. Tumor grading experiences changes, integrating molecular biomarkers for prognosis. The concept of integrated layered diagnosis is emphasized, where molecular and histological information is combined systematically. Conclusion: The 5th edition of the WHO CNS classification signifies a paradigm shift toward molecular characterization. The incorporation of molecular advances, the layered diagnostic approach, and the inclusion of clinical, morphological, and molecular information aim to provide comprehensive insights into pediatric CNS tumors. This classification offers valuable guidance for pediatric neurosurgeons, aiding in precise diagnosis and treatment planning for these complex neoplasms.

REVIEW: Evidence supporting the 'preparation for oxidative stress' (POS) strategy in animals in their natural environment.

Hypometabolism is a common strategy employed by resilient species to withstand environmental stressors that would be life-threatening for other organisms. Under conditions such as hypoxia/anoxia, temperature and salinity stress, or seasonal changes (e.g. hibernation, estivation), stress-tolerant species down-regulate pathways to decrease energy expenditures until the return of less challenging conditions. However, it is with the return of these more favorable conditions and the reactivation of basal metabolic rates that a strong increase of reactive oxygen and nitrogen species (RONS) occurs, leading to oxidative stress. Over the last few decades, cases of species capable of enhancing antioxidant defenses during hypometabolic states have been reported across taxa and in response to a variety of stressors. Interpreted as an adaptive mechanism to counteract RONS formation during tissue hypometabolism and reactivation, this strategy was coined "Preparation for Oxidative Stress" (POS). Laboratory experiments have confirmed that over 100 species, spanning 9 animal phyla, apply this strategy to endure harsh environments. However, the challenge remains to confirm its occurrence in the natural environment and its wide applicability as a key survival element, through controlled experimentation in field and in natural conditions. Under such conditions, numerous confounding factors may complicate data interpretation, but this remains the only approach to provide an integrative look at the evolutionary aspects of ecophysiological adaptations. In this review, we provide an overview of representative cases where the POS strategy has been demonstrated among diverse species in natural environmental conditions, discussing the strengths and weaknesses of these results and conclusions.

Comprehensive analysis of MYB/MYBL1-altered pediatric-type diffuse low-grade glioma.

BACKGROUND: Pediatric-type diffuse low-grade gliomas (pLGG) harboring recurrent genetic alterations involving MYB or MYBL1 are closely related tumors. Detailed treatment and outcome data of large cohorts are still limited. This study aimed to comprehensively evaluate pLGG with these alterations to define optimal therapeutic strategies. METHODS: We retrospectively reviewed details of pLGG with MYB or MYBL1 alterations from patients treated or referred for pathologic review at St. Jude Children's Research Hospital. Tumor specimens were centrally reviewed, and clinical data were collated. RESULTS: Thirty-three patients (18 male; median age, 5 y) were identified. Two tumors had MYBL1 alterations; 31 had MYB alterations, MYB::QKI fusion being the most common (n=10, 30%). Most tumors were in the cerebral hemispheres (n=22, 67%). Two patients (6%) had metastasis at diagnosis. The median follow-up was 6.1 years. The 5-year event-free survival (EFS) rate was 81.3±8.3%; the 5-year overall survival (OS) rate was 96.4±4.1%. Patients receiving a near-total or gross-total resection had a 5-year EFS of 100%; those receiving a biopsy or subtotal resection had a 5-year EFS rate of 56.6±15.2% (p<0.01). No difference in EFS was observed based on location, histology, or molecular alterations. However, the tumors that progressed or metastasized may have distinct methylation profiles with evidence of activation of the MAPK and PI3K/AKT/mTOR pathways. CONCLUSIONS: pLGG with MYB/MYBL1 alterations have good outcomes. Our findings suggest that surgical resectability is a crucial determinant of EFS. Further characterization is required to identify optimal treatment strategies for progressive tumors.

Challenges in treating children with optic pathway gliomas: an 18-year experience from a middle-income country.

Introduction: Patients with optic pathway gliomas (OPG) have good survival rates although their long-term quality of life can be affected by the tumor or treatment-related morbidity. This retrospective study sought to describe the clinical presentation and outcomes of children with OPG at a tertiary center in Mexico. Methods: Consecutive patients <18 years-of-age with newly diagnosed OPG between January 2002 and December 2020 at the Hospital Civil de Guadalajara Dr. Juan I. Menchaca in Guadalajara, Mexico were included. Results: Thirty patients were identified with a median age of six years. The most frequent clinical manifestations were loss of visual acuity (40%) and headaches (23%). Neurofibromatosis-1 was found in 23.3% of the patients. Surgery, either biopsy or resection, was done in 20 of 30 patients. Two patients died shortly after initial surgery. The 5-year event-free survival (EFS) was 79.3% ± 10.8% and the 5-year overall survival was 89.5% ± 6.9%. Lower EFS was associated with age less than 3 years, intracranial hypertension at presentation, and diencephalic syndrome. Patients who received surgery as first-line treatment had a 3.1 times greater risk of achieving a performance score of less than 90 points at 6 months after diagnosis (p=0.006). Of 10 patients with vision testing, 5 had improvement in visual acuity, 4 had no changes, and one patient showed worsening. Conclusion: Our data suggests that favorable outcomes can be achieved with OPG in low- and middle-income countries, although a high rate of surgical complications was described leading to a lower overall survival. These data can be used prospectively to optimize treatment at this institute and other middle-income countries through a comprehensive, multidisciplinary approach.

Evaluation of factors leading to poor outcomes for pediatric acute lymphoblastic leukemia in Mexico: a multi-institutional report of 2,116 patients.

Background and aims: Pediatric acute lymphoblastic leukemia (ALL) survival rates in low- and middle-income countries are lower due to deficiencies in multilevel factors, including access to timely diagnosis, risk-stratified therapy, and comprehensive supportive care. This retrospective study aimed to analyze outcomes for pediatric ALL at 16 centers in Mexico. Methods: Patients <18 years of age with newly diagnosed B- and T-cell ALL treated between January 2011 and December 2019 were included. Clinical and biological characteristics and their association with outcomes were examined. Results: Overall, 2,116 patients with a median age of 6.3 years were included. B-cell immunophenotype was identified in 1,889 (89.3%) patients. The median white blood cells at diagnosis were 11.2.5 × 103/mm3. CNS-1 status was reported in 1,810 (85.5%), CNS-2 in 67 (3.2%), and CNS-3 in 61 (2.9%). A total of 1,488 patients (70.4%) were classified as high-risk at diagnosis. However, in 52.5% (991/1,889) of patients with B-cell ALL, the reported risk group did not match the calculated risk group allocation based on National Cancer Institute (NCI) criteria. Fluorescence in situ hybridization (FISH) and PCR tests were performed for 407 (19.2%) and 736 (34.8%) patients, respectively. Minimal residual disease (MRD) during induction was performed in 1,158 patients (54.7%). The median follow-up was 3.7 years. During induction, 191 patients died (9.1%), and 45 patients (2.1%) experienced induction failure. A total of 365 deaths (17.3%) occurred, including 174 deaths after remission. Six percent (176) of patients abandoned treatment. The 5-year event-free survival (EFS) was 58.9% ± 1.7% for B-cell ALL and 47.4% ± 5.9% for T-cell ALL, while the 5-year overall survival (OS) was 67.5% ± 1.6% for B-cell ALL and 54.3% ± 0.6% for T-cell ALL. The 5-year cumulative incidence of central nervous system (CNS) relapse was 5.5% ± 0.6%. For the whole cohort, significantly higher outcomes were seen for patients aged 1-10 years, with DNA index >0.9, with hyperdiploid ALL, and without substantial treatment modifications. In multivariable analyses, age and Day 15 MRD continued to have a significant effect on EFS. Conclusion: Outcomes in this multi-institutional cohort describe poor outcomes, influenced by incomplete and inconsistent risk stratification, early toxic death, high on-treatment mortality, and high CNS relapse rate. Adopting comprehensive risk-stratification strategies, evidence-informed de-intensification for favorable-risk patients and optimized supportive care could improve outcomes.

Redox Metabolism in Ecophysiology and Evolution.

Aerobic organisms have developed a complex system of endogenous antioxidants to manage the reactivity of oxygen and its byproducts [...].

RGBradford: Protein Quantitation with a Smartphone Camera.

Protein quantitation is an essential procedure in life sciences research. Amongst several other methods, the Bradford assay is one of the most used. Because of its widespread, the limitations and advantages of the Bradford assay have been exhaustively reported, including several modifications of the original method to improve its performance. One of the alterations of the original method is the use of a smartphone camera as an analytical instrument. Taking advantage of the three forms of the Coomassie Brilliant Blue dye that exist in the conditions of the Bradford assay, this paper describes how to accurately quantify protein in samples using color data extracted from a single picture of a microplate. After performing the assay in a microplate, a picture is taken using a smartphone camera, and RGB color data is extracted from the picture using a free and open-source image analysis software application. Then, the ratio of blue to green intensity (in the RGB scale) of samples with unknown concentrations of protein is used to calculate the protein content based on a standard curve. No significant difference is observed between values calculated using RGB color data and those calculated using conventional absorbance data.

The Greatest Healthcare Disparity: Addressing Inequities in the Treatment of Childhood Central Nervous System Tumors in Low- and Middle-Income Countries.

The antithesis between childhood cancer survival rates in low- and middle-income countries (LMIC) and high-income countries (HIC) represents one of healthcare's most significant disparities. In HICs, the 5-year survival rate for children with cancer, including most brain tumors, exceeds 80%. Unfortunately, children in LMICs experience far worse outcomes with 5-year survival rates as low as 20%. To address inequities in the treatment of childhood cancer and disease burden globally, the World Health Organization (WHO) launched the Global Initiative for Childhood Cancer. Within this initiative, pediatric low-grade glioma (LGG) represents a unique opportunity for the neurosurgical community to directly contribute to a paradigm shift in the survival outcomes of children in LMICs, as many of these tumors can be managed with surgical resection alone. In this chapter, we discuss the burden of pediatric LGG and outline actions the neurosurgical community might consider to improve survival for children with LGG in LMICs.

Development of EPAT: An assessment tool for pediatric hematology/oncology training programs.

PURPOSE: In the absence of a standardized tool to assess the quality of pediatric hematology/oncology training programs, the Education Program Assessment Tool (EPAT) was conceptualized as a user-friendly and adaptable tool to evaluate and identify areas of opportunity, pinpoint needed modifications, and monitor progress for training programs around the world. METHODS: The development of EPAT consisted of three main phases: operationalization, consensus, and piloting. After each phase, the tool was iteratively modified based on feedback to improve its relevance, usability, and clarity. RESULTS: The operationalization process led to the development of 10 domains with associated assessment questions. The two-step consensus phase included an internal consensus phase to validate the domains and a subsequent external consensus phase to refine the domains and overall function of the tool. EPAT domains for programmatic evaluation are hospital infrastructure, patient care, education infrastructure, program basics, clinical exposure, theory, research, evaluation, educational culture, and graduate impact. EPAT was piloted in five training programs in five countries, representing diverse medical training and patient care contexts for proper validation of the tool. Face validity was confirmed by a correlation between the perceived and calculated scores for each domain (r = 0.78, p < .0001). CONCLUSIONS: EPAT was developed following a systematic approach, ultimately leading to a relevant tool to evaluate the different core elements of pediatric hematology/oncology training programs across the world. With EPAT, programs will have a tool to quantitatively evaluate their training, allowing for benchmarking with centers at the local, regional, and international level.

The role of neurosurgery in advancing pediatric CNS tumor care worldwide.

Introduction: There is substantial inequity in survival outcomes for pediatric brain tumor patients residing in high-income countries (HICs) compared to low- and middle-income countries (LMICs). To address disparities in pediatric cancer survival, the World Health Organization (WHO) established the Global Initiative for Childhood Cancer (GICC) to expand quality care for children with cancer. Research question: To provide an overview of pediatric neurosurgical capacity and detail the burden of neurosurgical diseases impacting children. Material and methods: A narrative review of the current context of global pediatric neurosurgical capacity as it relates to neurooncology and other diseases relevant to children. Results: In this article, we provide an overview of pediatric neurosurgical capacity and detail the burden of neurosurgical diseases impacting children. We highlight concerted advocacy and legislative efforts aimed at addressing unmet neurosurgical needs in children. Finally, we discuss the potential implications of advocacy efforts on treating pediatric CNS tumors and outline strategies to improve global outcomes for children with brain tumors worldwide in the context of the WHO GICC. Discussion and conclusion: With both global pediatric oncology and neurosurgical initiatives converging on the treatment of pediatric brain tumors, significant strides toward decreasing the burden of pediatric neurosurgical diseases will hopefully be made.

Glutathione Depletion Disrupts Redox Homeostasis in an Anoxia-Tolerant Invertebrate.

The upregulation of endogenous antioxidants is a widespread phenomenon in animals that tolerate hypoxia/anoxia for extended periods. The identity of the mobilized antioxidant is often context-dependent and differs among species, tissues, and stresses. Thus, the contribution of individual antioxidants to the adaptation to oxygen deprivation remains elusive. This study investigated the role of glutathione (GSH) in the control of redox homeostasis under the stress of anoxia and reoxygenation in Helix aspersa, an animal model of anoxia tolerance. To do so, the total GSH (tGSH) pool was depleted with l-buthionine-(S, R)-sulfoximine (BSO) before exposing snails to anoxia for 6 h. Then, the concentration of GSH, glutathione disulfide (GSSG), and oxidative stress markers (TBARS and protein carbonyl) and the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose 6-phosphate dehydrogenase) were measured in foot muscle and hepatopancreas. BSO alone induced tGSH depletion by 59-75%, but no other changes happened in other variables, except for foot GSSG. Anoxia elicited a 110-114% increase in glutathione peroxidase in the foot; no other changes occurred during anoxia. However, GSH depletion before anoxia increased the GSSG/tGSH ratio by 84-90% in both tissues, which returned to baseline levels during reoxygenation. Our findings indicate that glutathione is required to withstand the oxidative challenge induced by hypoxia and reoxygenation in land snails.

The role of solar radiation and tidal emersion on oxidative stress and glutathione synthesis in mussels exposed to air.

Preparation for oxidative stress (POS) is a widespread adaptive response to harsh environmental conditions, whose hallmark is the upregulation of antioxidants. In contrast to controlled laboratory settings, animals are exposed to multiple abiotic stressors under natural field conditions. Still, the interplay between different environmental factors in modulating redox metabolism in natural settings remains largely unexplored. Here, we aim to shed light on this topic by assessing changes in redox metabolism in the mussel Brachidontes solisianus naturally exposed to a tidal cycle. We compared the redox biochemical response of mussels under six different natural conditions in the field along two consecutive days. These conditions differ in terms of chronology, immersion/emersion, and solar radiation, but not in terms of temperature. Animals were collected after being exposed to air early morning (7:30), immersed during late morning and afternoon (8:45-15:30), and then exposed to air again late afternoon towards evening (17:45-21:25), in two days. Whole body homogenates were used to measure the activity of antioxidant (catalase, glutathione transferase and glutathione reductase) and metabolic (glucose 6-phosphate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase and pyruvate kinase) enzymes, reduced (GSH) and disulfide (GSSG) glutathione levels, and oxidative stress markers (protein carbonyl and thiobarbituric acid reactive substances). Air and water temperature remained stable between 22.5 °C and 26 °C during both days. Global solar radiation (GSR) greatly differed between days, with a cumulative GSR of 15,381 kJ/m2 for day 1 and 5,489 kJ/m2 for day 2, whose peaks were 2,240 kJ/m2/h at 14:00 on day 1 and 952 kJ/m2/h at 12:00 on day 2. Compared with animals underwater, emersion during early morning did not elicit any alteration in redox biomarkers in both days. Air exposure for 4 h in the late afternoon towards evening caused oxidative damage to proteins and lipids and elicited GSH synthesis in animals that had been previously exposed to high GSR during the day. In the following day, when GSR was much lower, exposure to air under the same conditions (duration, time, and temperature) had no effect on any redox biomarker. These findings suggest that air exposure under low-intensity solar radiation is not sufficient to trigger POS in B. solisianus in its natural habitat. Thus, natural UV radiation is possibly a key environmental factor that combined to air exposure induces the POS-response to the stressful event of tidal variation in this coastal species.

Outcomes of SARS-CoV-2 infection in 126 children and adolescents with central nervous system tumors.

BACKGROUND: The Global Registry of COVID-19 in Childhood Cancer (GRCCC) seeks to describe the natural history of SARS-CoV-2 in children with cancer across the world. Here, we report the disease course and management of coronavirus disease 2019 (COVID-19) infection in the subset of children and adolescents with central nervous system (CNS) tumors who were included in the GRCCC until February 2021, the first data freeze. PROCEDURE: The GRCCC is a deidentified web-based registry of patients less than 19 years of age with cancer or recipients of a hematopoietic stem cell transplant and laboratory-confirmed SARS-CoV-2 infection. Demographic data, cancer diagnosis, cancer-directed therapy, and clinical characteristics of SARS-CoV-2 infection were collected. Outcomes were collected at 30 and 60 days post infection. RESULTS: The GRCCC included 1500 cases from 45 countries, including 126 children with CNS tumors (8.4%). Sixty percent of the cases were from middle-income countries, while no cases were reported from low-income countries. Low-grade gliomas, high-grade gliomas, and CNS embryonal tumors were the most common CNS cancer diagnoses (67%, 84/126). Follow-up at 30 days was available for 107 (85%) patients. Based on the composite measure of severity, 53.3% (57/107) of reported SARS-CoV-2 infections were asymptomatic, 39.3% (42/107) were mild/moderate, and 6.5% (7/107) were severe or critical. One patient died from SARS-CoV-2 infection. There was a significant association between infection severity and absolute neutrophil count less than 500 (p = .04). Of 107 patients with follow-up available, 40 patients (37.4%) were not receiving cancer-directed therapy. Thirty-four patients (50.7%) had a modification to their treatment due to withholding of chemotherapy or delays in radiotherapy or surgery. CONCLUSION: In this cohort of patients with CNS tumors and COVID-19, the frequency of severe infection appears to be low, although severe disease and death do occur. We found that greater severity was seen in patients with severe neutropenia, although treatment modifications were not associated with infection severity or cytopenias. Additional analyses are needed to further describe this unique group of patients.

Communication transforms the impact of the COVID-19 pandemic on children with cancer and their families.

BACKGROUND: The COVID-19 pandemic altered healthcare systems globally, causing delays in care delivery and increased anxiety among patients and families. This study examined how hospital stakeholders and clinicians perceived the global impact of the COVID-19 pandemic on children with cancer and their families. METHODS: This secondary analysis examined data from a qualitative study consisting of 19 focus groups conducted in 8 languages throughout 16 countries. A codebook was developed with novel codes derived inductively from transcript review. In-depth analysis focused on the impact of the COVID-19 pandemic on children with cancer and their families. RESULTS: Eight themes describing the impact of the pandemic on patients and their families were identified and classified into three domains: contributing factors (COVID-19 Policies, Cancer Treatment Modifications, COVID-19 Symptoms, Beliefs), patient-related impacts (Quality of Care, Psychosocial impacts, Treatment Reluctance), and the central transformer (Communication). Participants described the ability of communication to transform the effect of contributing factors on patient-related impacts. The valence of impacts depended on the quality and quantity of communication among clinicians and between clinicians and patients and families. CONCLUSIONS: Communication served as the central factor impacting whether the COVID-19 pandemic positively or negatively affected children with cancer and families. These findings emphasize the key role communication plays in delivering patient-centered care and can guide future development of communication-centered interventions globally.

Pediatric Neurosurgical Capacity for the Care of Children With CNS Tumors Worldwide: A Cross-Sectional Assessment.

PURPOSE: Efforts to address inequities in the treatment of pediatric CNS tumors and the burden of childhood cancer globally have prompted the designation of low-grade glioma as one of six index cancers for the World Health Organization Global Initiative for Childhood Cancer. Understanding the importance of neurosurgical interventions and evaluating pediatric neurosurgical capacity may identify critical interventions to improve outcomes for children with low-grade glioma and other CNS tumors. METHODS: An online, cross-sectional survey assessing pediatric neurosurgical practice and capacity was distributed to members of the International Society of Pediatric Neurosurgery. The survey included 36 items covering domains including patient volume, available infrastructure, scope of practice, case distribution, and multidisciplinary care. RESULTS: Responses from 196 individuals from 61 countries, spanning all WHO regions, were included. Ninety-six (49.0%) were from high-income countries, 57 (29.1%) were from upper-middle-income countries, 42 (21.4%) were from lower-middle-income countries (LMICs), and 1 was (0.5%) from a low-income country. Most respondents had a catchment population of ≥ 1 million and indicated the availability of basic neurosurgical resources such as a dedicated neurosurgical operating theater and surgical microscope. The presence of a neurosurgical intensive care unit, inpatient rehabilitation services, and infection monitoring showed similar availability across country groups. Quantitative scoring of 13 infrastructure and service items established that fewer resources were available in low-income countries/LMICs and upper-middle-income countries compared with high-income countries. The volume of pediatric CNS tumor cases and case distribution did not vary according to World Bank country groups. CONCLUSION: This study provides a comprehensive evaluation of pediatric neurosurgical capacity across the globe, establishing variability of resources on the basis of the country income level. Our findings suggest that pediatric neurosurgeons in LMICs may benefit from key neurosurgical instrumentation and increased support for multidisciplinary brain tumor programs and childhood cancer research efforts.

Commentary: On the merit of an early contributor of the "Preparation for Oxidative Stress" (POS) theory.

This commentary acknowledges the contributions of the Ukrainian biologist, Dr. Volodymyr Lushchak, to the understanding of the physiological adaptive strategy called "Preparation for Oxidative Stress" (POS). In the 1990s, various studies revealed that activities of antioxidant enzymes rose in animals under hypometabolic conditions. These timely observations allowed scientists to propose that this increase could prepare animals for reoxygenation events following the release of oxygen restriction, but in doing so, would trigger oxidative damage, hence the use of the term "preparation". Over next 25 years, the phenomenon was described in detail in more than one hundred studies of animals under conditions of aestivation, hypoxia/anoxia, freezing, severe dehydration, ultraviolet exposure, air exposure of water-breathing animals, salinity stress, and others. The POS phenomenon remained without a mechanistic explanation until 2013, when it was proposed that a small increase in oxyradical formation during hypoxia exposure (in hypoxia-tolerant animals) could activate redox-sensitive transcription factors that, in turn, would initiate transcription and translation of antioxidant enzymes. Dr. Lushchak, who studied goldfish under severe hypoxia in the 1990s, had actually proposed the increased production of oxyradicals under this condition and concluded that it would lead to an upregulation of antioxidant enzymes, the hallmark of the POS strategy. However, his research partner at the time, Dr. Hermes-Lima, thought the idea did not have sufficient evidence to support it and recommended the removal of this explanation. In those days, the main line of thinking was that increased oxyradical formation under hypoxia was "impossible". So, as it turns out, the ideas of Dr. Lushchak were well ahead of his time. It then took >10 years before the biochemical and molecular mechanisms responsible for triggering the POS response were clarified. In the present article, this fascinating history is described to highlight Dr. Lushchak's contributions and insights about the POS theory.

An international multicenter survey reveals health care providers' knowledge gap in childhood central nervous system tumors.

Childhood central nervous system (CNS) tumors have longer delays in diagnosis than do other pediatric malignancies because health care providers (HCPs) lack awareness about clinical presentation of these tumors. To evaluate the knowledge gap among HCPs, we conducted a global cross-sectional survey. The survey consisted of a set of CNS tumor knowledge questions focused on symptoms, signs, and imaging indications. The survey was disseminated to HCPs via email (November 2018-March 2020). Participants had to complete a pre-test survey, attend an education seminar on CNS tumors, and complete a post-test survey. The knowledge gap was evaluated using pre-test and post-test scores. We received 889 pre-test and 392 post-test responses. Most respondents were from Asia (73.1% of pre-test responses; 87.5% of post-test responses). The median pre-test score was 40.0% (range: 13.1-92.9%). A high percentage of correct answers were given in post-test responses (median score: 77.1%, range: 14.9-98.2%). In the pre-test, 18.7% of participants accurately responded that Cushing's triad was a less common symptom, and 15.0% recognized that children aged > 10 years are at risk of late diagnosis. Surprisingly, 21.9% falsely reported that patients with malignancy experienced the longest pre-diagnostic symptom interval, and 54.5% of respondents wrongly selected medulloblastoma as the most common CNS tumor. Overall, pediatricians demonstrated a greater knowledge gap on both surveys than did other specialties.  Conclusion: Pre- and post-test surveys revealed significant knowledge gaps in childhood CNS tumors among HCPs. Thus, raising professional awareness on clinical presentations of CNS tumors through educational strategies is important to address this knowledge deficit. What is Known: • Diagnostic delay in childhood central nervous system (CNS) tumors continues to be a significant problem that negatively impacts the quality of life and treatment sequelae. • Lack of medical education on CNS tumors is a contributing factor to this problem. What is New: • Most health care providers do not realize that low-grade tumors are the most common neoplasm in children. • Health care providers fail to recognize that teenagers and adolescents are a vulnerable age group for diagnostic delays, with the longest pre-diagnostic symptom interval.