Brain tumors in children

Palliative Care for Children and Adolescents with Non-curative Brain Tumors: A Scoping Review

Children with non-curative brain tumors have a predictable and burdensome neurological decline. Care provision for these children falls in the gap where the acute inpatient services intersect with community-based providers. These children commonly receive care in the community; however, their neurological decline often outpaces engagement with community-based providers. Children with non-curative brain tumors are commonly referred to specialist palliative care services and need timely availability and access to this support. The purpose of this scoping review was to explore the evidence related to standards, guidelines, and models of palliative care provision for children with non-curative brain tumors, and to examine the facilitators and barriers to the implementation of, and access to, these services. Using a narrative synthesis method, a scoping review was conducted according to the Joanna Briggs Institute methodology using six electronic databases (Medline, Embase, Web of Science, Pubmed, CINAHL, and Cochrane Database of Systematic Reviews) from January 2013 to May 2023. A total of 2404 studies were screened for eligibility and 31 were selected for data extraction. There are no international models or standards of care for providing palliative care for children with non-curative brain tumors. Instead, palliative care is delivered at an institutional level, potentially leading to variability in the care that is provided. This variability can threaten the quality of life of these children and their families. Variability in care provision could be minimized by development of standardized palliative care provision. Any proposed standard for palliative care provision for children with non-curative brain tumors should include early integration of palliative care, and allocation of resources to enable training to operationalize referrals to palliative care teams and multidisciplinary care provision across settings, especially home-based care.

Characterizing the Natural History of Pediatric Brain Tumors Presenting with Metastasis

BACKGROUND

The natural history of pediatric patients with metastasis of primary brain tumors within and outside the central nervous system is poorly understood, as too are possible clinical correlates with outcome. Correspondingly, the aim of this study was to interrogate a national database to characterize this diagnosis and its clinical course in pediatric patients.

METHODS

The U.S. National Cancer Database (NCDB) was interrogated between the years 2005-2016 for all patients aged 18 years and younger with a primary brain tumor diagnosis, as well as evidence of disease metastasis at initial diagnosis. Data were summarized and overall survival (OS) was modeled using Kaplan-Meier and Cox regression analyses.

RESULTS

Out of a total of 8615 pediatric brain tumor patients, 356 (4%) had evidence of metastasis at initial diagnosis. Compared to patients without metastasis, patients with metastasis were statistically younger, more often male, and less likely to have private health insurance (all p < 0.050). With respect to clinical characteristics, the primary tumors of patients with metastasis were statistically more likely to be located in the cerebellum; be of higher histologic grading, with a higher proportion of medulloblastoma diagnoses and lower proportion of malignant glioma and pilocytic astrocytoma diagnoses; and were more likely to be treated by subtotal surgical resection, chemotherapy and radiation therapy (all p < 0.050) when compared to patients without metastasis. Five-year OS for those with metastasis was significantly lower than those without (48% vs. 75%, p < 0.001), with the median overall survival for patients with metastasis being 53 months (95% CI 29-86). Multivariate analysis indicated that a shorter OS was independently associated with the primary diagnoses of malignant glioma (HR 27.7, p = 0.020) and Atypical Teratoid/Rhabdoid Tumor (ATRT, HR 41.1, p = 0.041) and with WHO grades 3 (HR 20.1, p = 0.012) and 4 (HR 11.5, p < 0.001). Longer OS was significantly and independently associated with surgery (HR 0.49, p < 0.001), chemotherapy (HR 0.53, p = 0.041), and radiation therapy (HR 0.57, p = 0.026).

CONCLUSIONS

Although uncommon, pediatric brain tumors with evidence of metastasis at initial diagnosis will present with a distinct socioeconomic and clinical profile compared to patients without metastasis. Multiple predictors are independently associated with overall prognosis, and understanding these features should be validated in prospective efforts to identify vulnerable patients earlier in order to maximize the impact of treatment.

The Pediatric Physiatric Posterior Fossa Symptoms scale: Impairments and outcome in pediatric inpatient rehabilitation for posterior fossa brain tumors

BACKGROUND

Clinical recognition of the postoperative neurologic sequelae of posterior fossa tumors is inconsistent. This study aimed to characterize functional impairments and recovery trajectories in pediatric patients admitted to inpatient rehabilitation following surgical resection of posterior fossa brain tumors. This study also introduces the Pediatric Physiatric Posterior Fossa Symptom scale (3PFSs) for serial assessment of postoperative symptoms in pediatric posterior fossa brain tumors.

METHODS

This retrospective cohort study included 49 patients aged 1.1 to 19.9 years admitted to a pediatric unit of a free-standing rehabilitation hospital following resection of a posterior fossa brain tumor. Functional Independence Measure for Children (WeeFIM) and 3PFSs scores at admission and discharge were the primary outcome measures.

RESULTS

Across the group, WeeFIM score improved from 51.5 ± 23.5 points at admission to 74.2 ± 28.2 points at discharge (t = 4.34, P < .001). The 3PFSs score also showed improvement from 10 [Interquartile range (IQR) = 9-12] points at admission to 8 [7-10] points at discharge (t = 9.3, P < .0001). While change in both the WeeFIM and 3PFSs captured statistically significant improvement in function, there was low interrating correlation (P > .7). In addition, mortality was correlated with a higher discharge 3PFSs score (P = .007) but not discharge WeeFIM score.

CONCLUSIONS

In pediatric patients with postoperative neurologic sequelae due to posterior fossa brain tumors, inpatient rehabilitation resulted in global and domain-specific functional improvements. This initial application of the 3PFSs demonstrates potential applicability for stratifying patients to appropriate levels of rehabilitation, capturing functionally relevant response to rehabilitation treatment, and prognosticating long-term outcomes. These initial results are promising but require additional validation in a larger cohort.

Multimodal deep learning improves recurrence risk prediction in pediatric low-grade gliomas

BACKGROUND

Postoperative recurrence risk for pediatric low-grade gliomas (pLGGs) is challenging to predict by conventional clinical, radiographic, and genomic factors. We investigated if deep learning (DL) of magnetic resonance imaging (MRI) tumor features could improve postoperative pLGG risk stratification.

METHODS

We used a pretrained DL tool designed for pLGG segmentation to extract pLGG imaging features from preoperative T2-weighted MRI from patients who underwent surgery (DL-MRI features). Patients were pooled from 2 institutions: Dana Farber/Boston Children's Hospital (DF/BCH) and the Children's Brain Tumor Network (CBTN). We trained 3 DL logistic hazard models to predict postoperative event-free survival (EFS) probabilities with (1) clinical features, (2) DL-MRI features, and (3) multimodal (clinical and DL-MRI features). We evaluated the models with a time-dependent Concordance Index (Ctd) and risk group stratification with Kaplan-Meier plots and log-rank tests. We developed an automated pipeline integrating pLGG segmentation and EFS prediction with the best model.

RESULTS

Of the 396 patients analyzed (median follow-up: 85 months, range: 1.5-329 months), 214 (54%) underwent gross total resection and 110 (28%) recurred. The multimodal model improved EFS prediction compared to the DL-MRI and clinical models (Ctd: 0.85 (95% CI: 0.81-0.93), 0.79 (95% CI: 0.70-0.88), and 0.72 (95% CI: 0.57-0.77), respectively). The multimodal model improved risk-group stratification (3-year EFS for predicted high-risk: 31% versus low-risk: 92%, P < .0001).

CONCLUSIONS

DL extracts imaging features that can inform postoperative recurrence prediction for pLGG. Multimodal DL improves postoperative risk stratification for pLGG and may guide postoperative decision-making. Larger, multicenter training data may be needed to improve model generalizability.

Evidence of supratentorial white matter injury prior to treatment in children with posterior fossa tumors using diffusion MRI

Background

Pediatric brain tumor survivors can have neurocognitive deficits that negatively impact their quality of life, but it is unclear if deficits are primarily caused by treatments, such as radiotherapy, or manifest earlier due to the tumor and related complications. The aim of this work is to characterize white matter injury caused by brain tumors, unrelated to treatment effects, and explore heterogeneity in these white matter abnormalities between individual patients.

Methods

We used diffusion tensor imaging and neurite orientation dispersion diffusion imaging to assess white matter injury in 8 posterior fossa tumor patients. A novel one-against-many approach was used by comparing an individual patient to 20 age- and sex-matched healthy controls to assess variability in white matter abnormalities between the posterior fossa tumor patients. White matter was analyzed at presentation (prior to treatment), postsurgery (24-72 hours after surgery), and at follow-up (3-18 months after surgery).

Results

We demonstrate white matter abnormalities in 5 posterior fossa tumor patients before treatment, likely related to tumor-induced hydrocephalus, which persisted after treatment. White matter changes were complex and patient-specific, and group-based comparisons with control subjects may fail to detect these individual abnormalities.

Conclusions

Identifying pretreatment white matter injury in posterior fossa tumor patients highlights the importance of personalized assessment of brain microstructure, which should be considered in minimizing neurocognitive deficits to improve patient quality of life.

Pediatric brain tumor classification using deep learning on MR images with age fusion

Purpose

To implement and evaluate deep learning-based methods for the classification of pediatric brain tumors (PBT) in magnetic resonance (MR) data.

Methods

A subset of the "Children's Brain Tumor Network" dataset was retrospectively used (n = 178 subjects, female = 72, male = 102, NA = 4, age range [0.01, 36.49] years) with tumor types being low-grade astrocytoma (n = 84), ependymoma (n = 32), and medulloblastoma (n = 62). T1w post-contrast (n = 94 subjects), T2w (n = 160 subjects), and apparent diffusion coefficient (ADC: n = 66 subjects) MR sequences were used separately. Two deep learning models were trained on transversal slices showing tumor. Joint fusion was implemented to combine image and age data, and 2 pre-training paradigms were utilized. Model explainability was investigated using gradient-weighted class-activation mapping (Grad-CAM), and the learned feature space was visualized using principal component analysis (PCA).

Results

The highest tumor-type classification performance was achieved when using a vision transformer model pre-trained on ImageNet and fine-tuned on ADC images with age fusion (Matthews correlation coefficient [MCC]: 0.77 ± 0.14, Accuracy: 0.87 ± 0.08), followed by models trained on T2w (MCC: 0.58 ± 0.11, Accuracy: 0.73 ± 0.08) and T1w post-contrast (MCC: 0.41 ± 0.11, Accuracy: 0.62 ± 0.08) data. Age fusion marginally improved the model's performance. Both model architectures performed similarly across the experiments, with no differences between the pre-training strategies. Grad-CAMs showed that the models' attention focused on the brain region. PCA of the feature space showed greater separation of the tumor-type clusters when using contrastive pre-training.

Conclusion

Classification of PBT on MR images could be accomplished using deep learning, with the top-performing model being trained on ADC data, which radiologists use for the clinical classification of these tumors.

Preoperative coagulopathy and blood transfusion requirements in children with intraventricular lesions undergoing neurosurgery: a retrospective cohort study

PURPOSE

Pediatric patients undergoing neurosurgery pose risk of perioperative hemorrhage and clotting dysfunction which is increased in tumors with high vascularity, endothelial exposure, and necrosis. Lesions affecting the ventricular system may arise from several etiologies, including rare tumors. The present study aimed to study the preoperative coagulation and transfusion profile of pediatric patients undergoing neurosurgery for intraventricular lesions.

METHODS

A retrospective study of all paediatric patients who underwent surgery for intraventricular lesion was included from June 2014 to June 2022. Demographic data, preoperative and postoperative investigations, intraoperative blood loss, blood product transfusion, and duration of surgery were noted. Postoperative outcomes were also assessed.

RESULTS

A total of 98 patients underwent surgery, the median age was 11.1 years (1.0 to 17.0), with a male predominance (50.9%). The median blood loss during surgery was 500 mL (300-812.5). The incidence of preoperative coagulopathy was 30.7%. The intraoperative packed blood cell and fresh frozen plasma transfusion requirement was noted in 50.9% and 5%, respectively. The median ICU stay and hospital stay was 6 days (3-10) and 14 days (4-77), respectively. The mortality rate in the study population was 7.7%.

CONCLUSION

This study highlights the multifactorial nature of perioperative blood loss and transfusion requirements in pediatric patients undergoing surgery for intraventricular lesions. Factors such as tumor histopathology, preoperative hemoglobin levels, and surgical duration play a crucial role in determining transfusion needs.

Medulloblastomas Initiated by Homologous Recombination Defects in Mice

Germline mutations of homologous-recombination (HR) genes are among the top contributors to medulloblastomas. A significant portion of human medulloblastomas exhibit genomic signatures of HR defects. Whether ablation of Brca2 and Palb2, and their related Brca1 and Bccip genes, in the mouse brain can differentially initiate medulloblastomas was explored here. Conditional knockout mouse models of these HR genes and a conditional knockdown of Bccip (shBccip-KD) were established. Deletion of any of these genes led to microcephaly and neurologic defects, with Brca1- and Bccip- producing the worst defects. Trp53 co-deletion significantly rescued the microcephaly with Brca1, Palb2, and Brca2 deficiency but exhibited limited impact on Bccip- mice. For the first time, inactivation of either Brca1 or Palb2 with Trp53 was found to induce medulloblastomas. Despite shBccip-CKD being highly penetrative, Bccip/Trp53 deletions failed to induce medulloblastomas. The tumors displayed diverse immunohistochemical features and chromosome copy number variation. Although there were widespread up-regulations of cell proliferative pathways, most of the tumors expressed biomarkers of the sonic hedgehog subgroup. The medulloblastomas developed from Brca1-, Palb2-, and Brca2- mice were highly sensitive to a poly (ADP-ribose) polymerase inhibitor but not the ones from shBccip-CKD mice. These models recapitulate the spontaneous medulloblastoma development with high penetrance and a narrow time window, providing ideal platforms to test therapeutic agents with the ability to differentiate HR-defective and HR-proficient tumors.

Genotype-Phenotype Correlation of GNAS Gene: Review and Disease Management of a Hotspot Mutation

Defects of the GNAS gene have been mainly associated with pseudohypoparathyroidism Ia. To date, pathogenic missense, frameshift, non-sense and splicing variants have been described in all the 13 exons of the GNAS gene. Of them, a specific mutation, namely the 4 bp deletion c.565_568delGACT, is currently considered a mutation hotspot. Recent articles performed genotype-phenotype correlations in patients with GNAS-related pseudohypoparathyroidism Ia (PHP1a) but a specific focus on this hotspot is still lacking. We reported two cases, from our department, of PHP1a associated with c.565_568delGACT deletion and performed a literature review of all the previously reported cases of the 4 bp deletion hotspot. We found a higher prevalence of brachydactyly, round face, intellectual disability and subcutaneous/heterotopic ossifications in patients with the c.565_568delGACT as compared to the other variants in the GNAS gene. The present study highlights the different prevalence of some clinical features in patients with the c.565_568delGACT variant in the GNAS gene, suggesting the possibility of a personalized diagnostic follow-up and surveillance for these patients.

Machine Learning Analysis in Diffusion Kurtosis Imaging for Discriminating Pediatric Posterior Fossa Tumors: A Repeatability and Accuracy Pilot Study

Background and purpose: Differentiating pediatric posterior fossa (PF) tumors such as medulloblastoma (MB), ependymoma (EP), and pilocytic astrocytoma (PA) remains relevant, because of important treatment and prognostic implications. Diffusion kurtosis imaging (DKI) has not yet been investigated for discrimination of pediatric PF tumors. Estimating diffusion values from whole-tumor-based (VOI) segmentations may improve diffusion measurement repeatability compared to conventional region-of-interest (ROI) approaches. Our purpose was to compare repeatability between ROI and VOI DKI-derived diffusion measurements and assess DKI accuracy in discriminating among pediatric PF tumors. Materials and methods: We retrospectively analyzed 34 children (M, F, mean age 7.48 years) with PF tumors who underwent preoperative examination on a 3 Tesla magnet, including DKI. For each patient, two neuroradiologists independently segmented the whole solid tumor, the ROI of the area of maximum tumor diameter, and a small 5 mm ROI. The automated analysis pipeline included inter-observer variability, statistical, and machine learning (ML) analyses. We evaluated inter-observer variability with coefficient of variation (COV) and Bland-Altman plots. We estimated DKI metrics accuracy in discriminating among tumor histology with MANOVA analysis. In order to account for class imbalances, we applied SMOTE to balance the dataset. Finally, we performed a Random Forest (RF) machine learning classification analysis based on all DKI metrics from the SMOTE dataset by partitioning 70/30 the training and testing cohort. Results: Tumor histology included medulloblastoma (15), pilocytic astrocytoma (14), and ependymoma (5). VOI-based measurements presented lower variability than ROI-based measurements across all DKI metrics and were used for the analysis. DKI-derived metrics could accurately discriminate between tumor subtypes (Pillai's trace: p < 0.001). SMOTE generated 11 synthetic observations (10 EP and 1 PA), resulting in a balanced dataset with 45 instances (34 original and 11 synthetic). ML analysis yielded an accuracy of 0.928, which correctly predicted all but one lesion in the testing set. Conclusions: VOI-based measurements presented improved repeatability compared to ROI-based measurements across all diffusion metrics. An ML classification algorithm resulted accurate in discriminating PF tumors on a SMOTE-generated dataset. ML techniques based on DKI-derived metrics are useful for the discrimination of pediatric PF tumors.

Longitudinal risk prediction for pediatric glioma with temporal deep learning

Pediatric glioma recurrence can cause morbidity and mortality; however, recurrence pattern and severity are heterogeneous and challenging to predict with established clinical and genomic markers. Resultingly, almost all children undergo frequent, long-term, magnetic resonance (MR) brain surveillance regardless of individual recurrence risk. Deep learning analysis of longitudinal MR may be an effective approach for improving individualized recurrence prediction in gliomas and other cancers but has thus far been infeasible with current frameworks. Here, we propose a self-supervised, deep learning approach to longitudinal medical imaging analysis, temporal learning, that models the spatiotemporal information from a patient's current and prior brain MRs to predict future recurrence. We apply temporal learning to pediatric glioma surveillance imaging for 715 patients (3,994 scans) from four distinct clinical settings. We find that longitudinal imaging analysis with temporal learning improves recurrence prediction performance by up to 41% compared to traditional approaches, with improvements in performance in both low- and high-grade glioma. We find that recurrence prediction accuracy increases incrementally with the number of historical scans available per patient. Temporal deep learning may enable point-of-care decision-support for pediatric brain tumors and be adaptable more broadly to patients with other cancers and chronic diseases undergoing surveillance imaging.

Intra-tumoral T cells in pediatric brain tumors display clonal expansion and effector properties

Brain tumors in children are a devastating disease in a high proportion of patients. Owing to inconsistent results in clinical trials in unstratified patients, the role of immunotherapy remains unclear. We performed an in-depth survey of the single-cell transcriptomes and clonal relationship of intra-tumoral T cells from children with brain tumors. Our results demonstrate that a large fraction of T cells in the tumor tissue are clonally expanded with the potential to recognize tumor antigens. Such clonally expanded T cells display enrichment of transcripts linked to effector function, tissue residency, immune checkpoints and signatures of neoantigen-specific T cells and immunotherapy response. We identify neoantigens in pediatric brain tumors and show that neoantigen-specific T cell gene signatures are linked to better survival outcomes. Notably, among the patients in our cohort, we observe substantial heterogeneity in the degree of clonal expansion and magnitude of T cell response. Our findings suggest that characterization of intra-tumoral T cell responses may enable selection of patients for immunotherapy, an approach that requires prospective validation in clinical trials.

Dietary patterns and their associations with sociodemographic and lifestyle factors in adult survivors of childhood cancer: a cross-sectional study

BACKGROUND

Little is known about the specific dietary patterns in adult survivors of childhood cancer.

OBJECTIVES

We aimed to identify dietary patterns specific to childhood cancer survivors and examine their associations with sociodemographic and lifestyle factors.

METHODS

Adult survivors of childhood cancer (mean:31 ± 8 y; n = 3022) and noncancer controls (n = 497) in the St. Jude Lifetime Cohort self-reported diet over the past 12 mo using a validated food frequency questionnaire. Factor analysis with 48 predefined food groups was performed to identify foods consumed together. Subsequently, cluster analysis with energy-adjusted factor scores was used to categorize survivors into a mutually exclusive dietary pattern. Dietary patterns were the primary outcomes. Multivariable multinomial logistic regressions were used to cross-sectionally examine associations between sociodemographic and lifestyle factors and dietary patterns in cancer survivors.

RESULTS

Among the 4 dietary patterns identified, the fast-food pattern (36 %) was the most common, followed by the Western contemporary (30 %), the plant-based (20 %), and the animal-based (14 %) patterns in childhood cancer survivors. By contrast, the plant-based (38 %) and fast-food patterns (29 %) were prevalent in controls. In survivors, male sex, younger age, lower educational attainment, and physical inactivity were associated with the fast-food, Western contemporary, or animal-based pattern. Compared with non-Hispanic White survivors consuming the plant-based diet, non-Hispanic Black survivors were 2-5 times more likely to consume the fast-food [odds ratio (OR:= 2.76; 95 % CI: 1.82, 4.18) or the animal-based diet (OR: 5.61; 95 % CI: 3.58, 8.78)]. Moreover, survivors residing in the most deprived area were 2-3 times more likely to consume the fast-food, Western contemporary, or animal-based diet.

CONCLUSIONS

Unhealthy dietary patterns are prevalent in adult survivors of childhood cancer, especially those with lower socioeconomic status and racial minorities. Interventions to improve diet and health in childhood cancer survivors need to concurrently address disparities that contribute to adherence to healthy dietary practices. This trial was registered at clinicaltrials.gov as NCT00760656 (https://classic.

CLINICALTRIALS

gov/ct2/show/NCT00760656).

The epidemiologic associations of food availability with national incidence and mortality rates of pediatric central nervous system tumors

BACKGROUND

The epidemiology of central nervous system (CNS) tumors in pediatric patients worldwide continues to be defined. To date, there has been no evaluation of how national food availability may associate with the incidence and mortality of these tumors. Correspondingly, the aim of this study was to define if such associations exist.

METHODS

The most updated incidence and mortality rates of CNS tumors in pediatric patients were abstracted by country from the Global Burden of Disease database. Data regarding food availability parameters were identified and abstracted from the Food Systems Dashboard database. Associations were tested using univariate and multivariate regression analyses.

RESULTS

There were sufficient data in a total of 175 countries worldwide describing the required outcomes. Median incidence and mortality rates across these countries were 1.63 per 100,000 and 0.80 per 100,000, respectively. Higher incidence rates of pediatric CNS tumors were statistically associated with lower availability of fruit and vegetables (P = 0.02), higher average protein supply (P < 0.01), lower share of dietary energy from cereal and roots (P < 0.01), lower supply of meat (P < 0.01), lower supply of nuts and seeds (P < 0.01), lower supply of vegetable oils (P < 0.01), and higher supply of vegetables (P < 0.01). Higher mortality rates due to pediatric CNS tumors were statistically associated with lower availability of fruit and vegetables (P = 0.048), lower supply of fish (P = 0.046), and lower supply of nuts and seeds (P = 0.04). When categorizing countries based on income status, there was a decrease in significant associations found more pronounced in low-middle income countries.

CONCLUSIONS

There are many novel associations between national food availability and the incidence and mortality rates of pediatric CNS tumors across the world, which may be more pronounced and divergent in low-middle income countries. A greater understanding is needed to identify what specific components of the significant parameters influence these trends and how public health efforts may best address these associations to improve overall outcomes.

Chemotherapy in pediatric brain tumor and the challenge of the blood-brain barrier

BACKGROUND

Pediatric brain tumors (PBT) stand as the leading cause of cancer-related deaths in children. Chemoradiation protocols have improved survival rates, even for non-resectable tumors. Nonetheless, radiation therapy carries the risk of numerous adverse effects that can have long-lasting, detrimental effects on the quality of life for survivors. The pursuit of chemotherapeutics that could obviate the need for radiotherapy remains ongoing. Several anti-tumor agents, including sunitinib, valproic acid, carboplatin, and panobinostat, have shown effectiveness in various malignancies but have not proven effective in treating PBT. The presence of the blood-brain barrier (BBB) plays a pivotal role in maintaining suboptimal concentrations of anti-cancer drugs in the central nervous system (CNS). Ongoing research aims to modulate the integrity of the BBB to attain clinically effective drug concentrations in the CNS. However, current findings on the interaction of exogenous chemical agents with the BBB remain limited and do not provide a comprehensive explanation for the ineffectiveness of established anti-cancer drugs in PBT.

METHODS

We conducted our search for chemotherapeutic agents associated with the blood-brain barrier (BBB) using the following keywords: Chemotherapy in Cancer, Chemotherapy in Brain Cancer, Chemotherapy in PBT, BBB Inhibition of Drugs into CNS, Suboptimal Concentration of CNS Drugs, PBT Drugs and BBB, and Potential PBT Drugs. We reviewed each relevant article before compiling the information in our manuscript. For the generation of figures, we utilized BioRender software.

FOCUS

We focused our article search on chemical agents for PBT and subsequently investigated the role of the BBB in this context. Our search criteria included clinical trials, both randomized and non-randomized studies, preclinical research, review articles, and research papers.

FINDING

Our research suggests that, despite the availability of potent chemotherapeutic agents for several types of cancer, the effectiveness of these chemical agents in treating PBT has not been comprehensively explored. Additionally, there is a scarcity of studies examining the role of the BBB in the suboptimal outcomes of PBT treatment, despite the effectiveness of these drugs for other types of tumors.

Identification of Central Nervous System Oncologic Disease Biomarkers in EVs from Cerebrospinal Fluid (CSF) of Pediatric Patients: A Pilot Neuro-Proteomic Study

Cerebrospinal fluid (CSF) is a biochemical-clinical window into the brain. Unfortunately, its wide dynamic range, low protein concentration, and small sample quantity significantly limit the possibility of using it routinely. Extraventricular drainage (EVD) of CSF allows us to solve quantitative problems and to study the biological role of extracellular vesicles (EVs). In this study, we implemented bioinformatic analysis of our previous data of EVD of CSF and its EVs obtained from congenital hydrocephalus with the aim of identifying a comprehensive list of potential tumor and non-tumor biomarkers of central nervous system diseases. Among all proteins identified, those enriched in EVs are associated with synapses, synaptosomes, and nervous system diseases including gliomas, embryonal tumors, and epilepsy. Among these EV-enriched proteins, given the broad consensus present in the recent scientific literature, we validated syntaxin-binding protein 1 (STXBP1) as a marker of malignancy in EVD of CSF and its EVs from patients with pilocytic astrocytoma and medulloblastoma. Our results show that STXBP1 is negatively enriched in EVs compared to non-tumor diseases and its downregulation correlates with adverse outcomes. Further experiments are needed to validate this and other EV markers in the blood of pediatric patients for translational medicine applications.

Global, Regional, and National Incidence and Mortality Trends in Pediatric Central Nervous System Tumors over the Past 2 Decades

BACKGROUND

Pediatric tumors of the brain and central nervous system (CNS) are a worldwide issue with variances in epidemiology. How exactly incidence and mortality rates have changed over time has not been summarized. Correspondingly, the aim of this study was to quantitively define the global, regional, and national epidemiological trends of these tumors.

METHODS

A retrospective review of data from the Global Burden of Disease Study 2019 Database was performed incorporating data from 1999 to 2019. Global, regional, and national outcomes for pediatric CNS tumors were collected for incidence and mortality at a worldwide level, as well as across 7 continental regions, and then 204 countries and territories.

RESULTS

Globally, the latest incidence of pediatric CNS tumors was 47,600 (uncertainty interval, 36,500-55,200) at a rate of 1.8 (1.4-2.2) per 100,000, with 23,500 (18,000-27,500) deaths due to these tumors at a rate of 0.9 (0.7-1.1) per 100,000 population. Both rates per 100,000 have decreased over the past 2 decades. With respect to regions, East Asia and Pacific had the highest incidence and mortality cases overall, but in terms of rate per 100,000, North America and Latin America and Caribbean had the highest values, respectively. There were 3/7 (43%) and 6/7 (86%) regions with decreasing incidence and mortality rates per 100,000 over the past 2 decades. China, India, and Pakistan were the 3 countries with both the highest incidence and mortality cases overall; however, San Marino, Denmark, and Norway had the highest incidence rates per 100,000, and Albania, Armenia, and Haiti had the highest mortality rates per 100,000. In the past 2 decades, 79/204 (39%) and 120/204 (59%) countries observed decreasing incidence and mortality rates per 100,000, respectively.

CONCLUSIONS

Pediatric CNS tumors remains a worldwide issue, with there being multiple regions and countries worldwide that continue to experience uptrending incidence and mortality rates per 100,000. For both incidence and mortality, there is a clear discordance between regions and countries that report the highest number of cases versus the highest rate of cases per 100,000. Future research efforts are needed to identify positive intervention measures that respect the epidemiology of these tumors at global, regional, and national levels.

"A tumour registry initiative"

Background

Published literature on epidemiological profile of paediatric brain tumours in India is limited. Aim: To present a retrospective analysis of the histological spectrum of 158 paediatric age group central nervous system tumours operated in a single tertiary care hospital in Coastal South India between January 2015 and December 2021.

Material and methods

Retrospective analysis of the data regarding frequencies of various primary brain tumours among 158 paediatric patients (<18 years of age). The tumours were categorised according to the revised 4th edition of World Health Organization (WHO) classification of tumours of the Central Nervous system.

Results

Paediatric CNS constituted 8.5% of total intracranial tumours (158/1860) operated in the study period. The mean age of the patients was 10.2 years and a definite male predominance was noted (1.54:1) Astrocytomas, glioneuronal tumours, and neuronal tumours constituted the majority (72/158; 45.6%) followed by embryonal tumours (31/158; 19.6%) and craniopharyngiomas(24/158; 15.4%).Of the glial neoplasms majority were pilocytic and other astrocytic tumours(41.6%), followed by mixed neuroglial tumours (19.4%), diffuse high grade astrocytomas (Grade III/IV) (11.1%), diffuse low -grade astrocytomas (Grade II) (9.7%) and ependymomas (13.8%). Our series also included six meningiomas (3.8%), five germ cell tumours (3.16%), four nerve sheath tumours (2.53%), two choroid plexus tumours (1.26%), two pineal parenchymal tumours (1.26%) and one metastasis from a soft tissue sarcoma from the thigh. Supratentorial tumours (58.2%) were more common than posterior fossa (34.6%) and spinal tumours (7.6%) and visual pathway gliomas accounted for 5.6% of all our tumours.

Conclusions

Paediatric central nervous system tumours are more common in boys and in the second decade of life. Astrocytomas are the most common paediatric brain tumours followed by medulloblastomas and craniopharyngiomas. Pediatric tumours affect the supratentorial compartment more often than the infratentorial compartment. The profile of paediatric brain tumours in our series is similar to that reported from other Indian centres as well as most western literature.

Characterizing Various Posterior Fossa Tumors in Children and Adults With Diffusion-Weighted Imaging and Spectroscopy

Background The posterior fossa is situated between the tentorium cerebelli above and the foramen magnum below. Vital structures like the cerebellum, the pons, and the medulla are situated within it; hence, tumors within the posterior fossa are considered one of the most critical brain lesions. Children are more likely to develop posterior fossa tumors than adults. Diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) sequences along with the conventional MRI help in providing additional information in the characterization of the various posterior fossa tumors. We hereby present a series of 30 patients with clinically suspected posterior fossa masses who underwent preoperative MRI. Objectives This study aims to differentiate the neoplastic from non-neoplastic posterior fossa mass by evaluating the diffusion restriction pattern on DWI, quantifying the apparent diffusion coefficient (ADC) map in various posterior fossa tumors, and comparing the different metabolites of various posterior fossa tumors on MRS. Results Out of the 30 patients with posterior fossa lesions, 18 were males and 12 were females. Eight of them were in the pediatric age group, while twenty-two of them were adults. Metastasis was the most common posterior fossa lesion in our study sample and was found in six patients (20%), followed by vestibular schwannomas (17%) and arachnoid cysts (13%), meningiomas, medulloblastoma, and pilocytic astrocytoma (10% each) and epidermoid, ependymoma, and hemangioblastoma (7% each). The mean ADC value of benign tumors was higher than that of malignant tumors, and this difference was found to be significant (p = 0.012). The cut-off ADC value 1.21x 10^-3mm²/s had a sensitivity of 81.82% and specificity of 80.47%. MRS metabolites played an additional role in differentiating benign from malignant tumors. Conclusion A combination of conventional MRI, DWI, ADC values, and MRS metabolites showed good diagnostic accuracy to differentiate between the various posterior fossa neoplastic tumors both in adults and children.

Retrospective National "Real Life" Experience of the SFCE with the Metronomic MEMMAT and MEMMAT-like Protocol

BACKGROUND

Relapses in pediatric high-risk brain tumors remain unmet medical needs. Over the last 15 years, metronomic chemotherapy has gradually emerged as an alternative therapeutic approach.

PATIENTS AND METHODS

This is a national retrospective study of patients with relapsing pediatric brain tumors treated according to the MEMMAT or MEMMAT-like regimen from 2010 to 2022. Treatment consisted of daily oral thalidomide, fenofibrate, and celecoxib, and alternating 21-day cycles of metronomic etoposide and cyclophosphamide associated with bevacizumab and intraventricular chemotherapy.

RESULTS

Forty-one patients were included. The most frequent malignancies were medulloblastoma (22) and ATRT (8). Overall, the best responses were CR in eight patients (20%), PR in three patients (7%), and SD in three patients (7%), for a clinical benefit rate of 34%. The median overall survival was 26 months (IC95% = 12.4-42.7), and median EFS was 9.7 months (IC95% = 6.0-18.6). The most frequent grade ¾ toxicities were hematological. Dose had to be adjusted in 27% of the cases. There was no statistical difference in outcome between full or modified MEMMAT. The best setting seems to be when MEMMAT is used as a maintenance and at first relapse.

CONCLUSIONS

The metronomic MEMMAT combination can lead to sustained control of relapsed high-risk pediatric brain tumors.

Immunotherapy for Pediatric Brain and Spine Tumors: Current State and Future Directions

BACKGROUND

Brain tumors are the most common solid tumors and the leading cause of cancer-related deaths in children. Incidence in the USA has been on the rise for the last 2 decades. While therapeutic advances in diagnosis and treatment have improved survival and quality of life in many children, prognosis remains poor and current treatments have significant long-term sequelae.

SUMMARY

There is a substantial need for the development of new therapeutic approaches, and since the introduction of immunotherapy by immune checkpoint inhibitors, there has been an exponential increase in clinical trials to adopt these and other immunotherapy approaches in children with brain tumors. In this review, we summarize the current immunotherapy landscape for various pediatric brain tumor types including choroid plexus tumors, embryonal tumors (medulloblastoma, AT/RT, PNETs), ependymoma, germ cell tumors, gliomas, glioneuronal and neuronal tumors, and mesenchymal tumors. We discuss the latest clinical trials and noteworthy preclinical studies to treat these pediatric brain tumors using checkpoint inhibitors, cellular therapies (CAR-T, NK, T cell), oncolytic virotherapy, radioimmunotherapy, tumor vaccines, immunomodulators, and other targeted therapies.

KEY MESSAGES

The current landscape for immunotherapy in pediatric brain tumors is still emerging, but results in certain tumors have been promising. In the age of targeted therapy, genetic tumor profiling, and many ongoing clinical trials, immunotherapy will likely become an increasingly effective tool in the neuro-oncologist armamentarium.

Human papillomavirus vaccination uptake among childhood cancer survivors in Western New York

INTRODUCTION

The risk of human papillomavirus (HPV)-associated cancers is significantly higher among survivors of a childhood cancer compared to the general population. Despite this, their HPV vaccine uptake rates are lower. We examined factors related to HPV vaccine uptake among childhood cancer survivors from Western New York over 13 years following the introduction of HPV vaccines.

METHODS

Retrospective review of patients diagnosed with invasive or noninvasive cancerous conditions at age 9 or younger treated at Roswell Park Oishei Children's Cancer and Blood Disorder Program. We matched vaccine date information for patients aged 9-26 years between 2006 and 2020 from the New York State Immunization Information System. Demographic and cancer-related information was abstracted from electronic medical records. Cumulative vaccine uptake was assessed by Kaplan-Meier and Cox proportional hazards regression models.

RESULTS

A total of 284 patients were included in the analyses. Most were non-Hispanic/White (80.3%) and resided in a metropolitan area (81.7%). Approximately half had leukemia or lymphoma (54.9%), and most received chemotherapy. Females were more likely to initiate the HPV vaccine and did so sooner (median = 5.5 years) than males (median = 5.7 years; log-rank p = .301). Patients who were older at vaccine eligibility and males who received blood product transfusions were significantly less likely to initiate the HPV vaccine.

CONCLUSION

While rates of HPV vaccine initiation have been increasing with time among childhood cancer survivors, they remain low overall, with differences seen by treatment and diagnosis. Our findings support the need for further research to optimize HPV vaccine delivery in cancer care.

Special Anaesthetic Considerations for Brain Tumour Surgery in Children

Brain tumours are among the most common neoplasm in children. Therefore, paediatric anaesthesiologists face the challenge of neurosurgical interventions in all age groups. To minimize perioperative mortality and morbidity, a comprehensive understanding of age-dependent differences in anatomy and cerebrovascular physiology is a mandatory prerequisite. Advances in subspeciality training in paediatric neurosurgery and paediatric anaesthesia may improve clinical outcomes and advance communication between the teams.

Quality of life reporting in the management of posterior fossa tumours: A systematic review

Introduction

Survival amongst posterior fossa tumour (PFT) patients is improving. Clinical endpoints such as overall survival fail to depict QoL. There is yet to be a review of current QoL instruments used for adult PFTs. Aim of this review is to outline the QoL reporting in the management of PFTs and measure participation level.

Methods

This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis. A search strategy to identify adult patients with PFTs who took part in QoL metrics was conducted. Observational and experimental studies published from 1990 to date were included. Studies with a sample size less than 10 and performance measures such as Karnofsky Performance Status were not considered.

Results

A total of 116 studies were included in the final analysis. Vestibular schwannomas were the most common tumour pathology (n = 23,886, 92.6%) followed by pilocytic astrocytomas (n = 657, 2.5%) and meningiomas (n = 437, 1.7%) Twenty-five different QoL measures were used in the study pool. SF-36 was the most common (n = 55, 17 47.4%) QoL metric in the whole study pool, followed by the Penn Acoustic Neuroma QoL scale (n = 24, 20.7%) and Dizziness Handicap Inventory (n = 16, 13.8%). Seventy-two studies reported less-than 100% participation in QoL evaluation. The commonest reason for non-participation was a lack of response (n = 1,718, 60.8%), incomplete questionnaires (n = 268, 9.4%) and cognitive dysfunction (n = 258, 9.1%).

Conclusion

Informed clinical decision-making in PFT patients requires the development of specific QoL outcomes. Core outcome sets, and minimal clinically important differences (MCID) are essential for these metrics to show clinically significant improvements in patient QoL.

Racial disparities in pediatric malignant glioma management: current state of affairs in the United States

BACKGROUND

The diagnosis of malignant glioma confers a poor prognosis in the pediatric population. In the adult demographic, racial disparities exist with respect to access to care and survival. Yet to date no efforts have been made to characterize racial disparities in the care of malignant pediatric gliomas. Correspondingly, the aim of this study was to understand if racial disparities exist in the setting of malignant pediatric gliomas.

METHODS

All pediatric malignant gliomas patients with known race status (White, Black, Other) in the US National Cancer Database (NCDB) between the years 2005-2016 were retrospectively reviewed. Demographic, socioeconomic and clinical data were then abstracted and analyzed by comparison and regression techniques.

RESULTS

A total of 1803 pediatric malignant glioma cases were identified, with 48% female and a median age of 8 years old. Brainstem locations were reported in 48% of cases. Socioeconomically, there were statistically significant differences with respect to insurance status, yearly income, household education level and metropolitan residences between the racial groups (all P < 0.01). With respect to treatment, there was statistical difference in the proportion of patients treated with surgical resection (White 43% vs Black 34% vs Other 37%, P = 0.02). There were no differences between race groups for radiation therapy (P = 0.73) or chemotherapy (P = 0.12). The odds of surgical resection were significantly less in the Black group compared to the White group (OR 0.69, P < 0.01), although there was no difference in overall survival between the two groups in those treated with (P = 0.44) or without (P = 0.27) surgical resection. Primary associations of surgical resection in the Black group were brainstem location (P < 0.05) and lower yearly household income quartiles (P < 0.05).

CONCLUSIONS

Racial disparities exist amongst the management of pediatric malignant gliomas, with undefined impact on survival and quality of life. In this perspective, we identified associations between Black patients and access to surgical treatment. Understanding that there are many elements to patient care, including quality of life, should encourage all clinicians and carers to consider racial disparities appropriately when managing malignant pediatric glioma patients.

Pre- and postdiagnosis growth failure, adult short stature, and untreated growth hormone deficiency in radiotherapy-treated long-term survivors of childhood brain tumor

PURPOSE

Growth failure is common in radiotherapy-treated long-term survivors of pediatric brain tumors, but studies on longitudinal growth in this patient group are lacking. Here, the aim was to assess the changes in growth patterns before and after brain tumor diagnosis, the adult height, and the risk factors for compromised growth. The incidence and treatment practices of growth hormone deficiency were analyzed.

METHODS

A cohort of 73 survivors of childhood brain tumor (median age 27.2 years, range 16.2 to 43.8 years) was studied after a median follow-up period of 20.4 years from diagnosis (IQR 14.9 to 22.9 years). Patients were treated in five university hospitals in Finland between 1970 and 2008. Growth curves, final height, and patient- and disease-related risk factors for compromised growth during different growth periods were analyzed. Laboratory analyses for IGF-1 and IGFBP-3 were performed at the follow-up.

RESULTS

Growth failure was evident at diagnosis, with a mean height decline of -0.6 SDS (standard deviation score) from birth (95% CI -1.15 to -0.05). Mean height SDS decline after the diagnosis was -1.09 SDS (95%CI -1.51 to -0.66). At follow-up, 37% of the study subjects (27/73) had true short stature (height < -2 SDS). The mean height deficit corrected for target height was -1.9 SDS (95% CI -1.45 to -2.40). Growth failure was associated with the age at diagnosis, corticosteroid dose, radiotherapy modality and mean dose of irradiation in the thalamic area. Low IGF-1 level (below -2.0 SDS) was found in 32% (23/72), and untreated growth hormone deficiency in 40% (29/72) of the subjects.

CONCLUSION

Longitudinal growth impairment was common in radiotherapy-treated survivors of childhood brain tumor, resulting in compromised adult height. Loss of growth potential was evident already at diagnosis and further accelerated by the treatments. At young adulthood, unrecognized growth hormone deficiency was common.

Surgical outcomes of pediatric brain tumors in Sub-Saharan Africa: A systematic review

Background

Pediatric Brain Tumors (PBT) are a common cause of cancer-related mortality globally. Contrary to high-income countries (HIC), survival rates in low-and-middle income countries (LMIC) remains low despite advances in neurosurgical care and diagnostics over the past decades. The aim of this systematic review was to investigate the surgical outcomes for PBT in Sub-Saharan Africa, and the distribution of PBT types.

Methods

A systematic review was conducted on PubMed, for all available literature on the surgical outcomes of PBT in Sub-Saharan Africa, published before May 3, 2022. Two reviewers performed abstract, full text screening and data collection independently, resolving any conflicts by consensus.

Results

The search yielded 256 studies, of which 22 met the inclusion criteria, amounting to a total of 243 patients. Nigeria was the country with most data. Only subgroups of patients could be extracted from 12 studies, and variables of interest in 6 studies had inconsistent sample sizes. The age centered around 9 years, and there were approximately equal number of girls and boys. The most common tumor was medulloblastoma, followed by craniopharyngioma and astrocytoma. There was large heterogeneity in the reporting of outcomes, and a trend was difficult to discern, considering the large number of different tumor types and different extents of resection.

Discussion and conclusion

Data is insufficient and inconsistent, precluding statistical conclusions. There is a need for more studies in the field.

The role of m6A modification in pediatric cancer

With the development of RNA modification research, the importance of N6-methyladenosine (m6A) in tumors cannot be ignored. m6A promotes the self-renewal of tumor stem cells and the proliferation of tumor cells. It affects post-transcriptional gene expression through epigenetic mechanisms, combining various factors to determine proteins' fate and altering the biological function. This modification process runs through the entire tumors, and genes affected by m6A modification may be the critical targets for cancers breakthroughs. Though generally less dangerous than adult cancer, pediatric cancer accounts for a significant proportion of child deaths. What is more alarming is that the occurrences of adult tumors are highly associated with the poor prognoses of pediatric tumors. Therefore, it is necessary to pay attention to the importance of pediatric cancer and discover new therapeutic targets, which will help improve the therapeutic effect and prognoses of the diseases. We collected and investigated m6A modification in pediatric cancers based on mRNA and non-coding RNA, finding that m6A factors were involved in glioma, hepatoblastoma, nephroblastoma, neuroblastoma, osteosarcoma, medulloblastoma, retinoblastoma, and acute lymphoblastic leukemia. Consequently, we summarized the relationships between the m6A factors and these pediatric cancers.

Pre-operative dosing of dexamethasone for the management of children with posterior fossa tumours: are we getting it right?

INTRODUCTION

Posterior fossa (PF) tumours are associated with vasogenic oedema causing symptoms of raised intracranial pressure. Preoperatively this is managed with dexamethasone. To minimise steroid related complications, the lowest effective dose should be administered. No neurosurgical guidelines exist for pre-operative dosing of dexamethasone in PF tumours.

METHODS

A retrospective review was performed of surgically managed cases for patients under 16 years of age between 2013 and 2018 to ascertain the initial dose of dexamethasone with symptomatic PF tumours.

RESULTS

Thirty-six patients were identified of which 30 notes were available. Sixteen were male. Median age was 6 years (range 10 months - 15 years). Twenty-two (73%) were referrals from DGH and 8 (27%) presented to our neurosurgical centre. All patients presented with symptomatic PF tumours including headache (97%), vomiting (93%), gait disturbance (43%), and nystagmus (17%). Four (13%) had papilloedema. Average initial stat dexamethasone dose was 9.15 mg; 0.31 mg/kg (range 1-16.7 mg; 0.05 - 1.77 mg/kg). Stratified according to weight, average dose (and range) was 8.8 mg; 0.94 mg/kg (1-16.6 mg; 0.13 - 1.77 mg/kg) in those weighing <10 kg; 9.7 mg; 0.66 mg/kg (4-16.7 mg; 0.21 - 1.35 mg/kg) in 10-20 kg; 12.3 mg;0.52 mg/kg (8-16.7 mg; 0.27 - 0.73mg/kg) in 20-30 kg and 7.8 mg; 0.17mg/kg (2-16.7 mg; 0.0 - 0.39 mg/kg) in >30 kg up to a maximum of 16.6 mg in any 24h period. These results suggest that dosage was higher in those children weighing less. PPI was used in 24 (80%) of cases. All doses were reduced after review by the neurosurgical team and a PPI added.

CONCLUSION

Pre-operative dexamethasone dosing does not always reflect the severity of clinical symptoms for PF tumours. Guidelines are required to correlate clinical symptoms with a suggested suitable dose of dexamethasone to prevent overdose and complications associated with corticosteroid use. We recommend a weight-based regimen as provided by the Food and Drug Administration. The current advice is for 0.02-0.3mg/kg/day in 3-4 divided doses.

The feasibility and efficacy of short-term visual-motor training in pediatric posterior fossa tumor survivors

BACKGROUND

Pediatric posterior fossa tumor (PFT) survivors experience a range of cognitive and motor impairments that require timely rehabilitation of these functions. In Russia, rehabilitation services are only just beginning to be formed; therefore, it is necessary to test rehabilitation protocols for children surviving cancer.

AIM

To evaluate the efficacy of short-term cognitive and motor training (CMT) aimed on visual-motor integration in PFT survivors using training devices.

DESIGN

"Single center" quasi randomized controlled experiment.

SETTING

Outpatients of the Russkoe Pole Rehabilitation Center.

POPULATION

The 63 children cancer survivors between the ages of 6 and 17 years.

METHODS

The baseline level of cognitive and motor functions was assessed in all participants. Then the sample of patients split into two subgroups of equal sex, age, and diagnosis. The intervention subgroup received six sessions of CMT for two weeks, and the other subgroup underwent 'empty' two weeks with no intervention. Reassessment of motor and cognitive functions was conducted in all participants. Then the subgroups changed: the first subgroup underwent 'empty' two weeks, and the second subgroup completed the CMT, and further reassessment was provided.

RESULTS

The primary results demonstrate an increase in gross and fine motor skills, motor coordination, visual-motor integration, and visual processing after CMT. Secondary results show that the age at onset is an important factor in the subsequent decline in cognitive, motor functions, and eye movements. Children with medulloblastoma perform worse on motor tests than children with astrocytoma. A tumor in the IV ventricle is the most harmful, and a tumor in the cerebellar hemispheres is the least harmful to a child's cognitive and motor development.

CONCLUSIONS

This study shows the effectiveness of a short-term CMT program for children who survived PFT. The study also found that cognitive, motor, and visual-motor functions are affected by the tumor's localization, malignancy, and the child's age at onset.

CLINICAL REHABILITATION IMPACT

Short-term rehabilitation methods can be useful in pediatric oncological practice. Reconstruction of cognitive functions can occur during the training of more "simple" functions, such as hand-eye integration. The study makes a significant contribution to the methods of short-term rehabilitation in children who survived cancer.

Diagnostic accuracy of qualitative MRI in 550 paediatric brain tumours: evaluating current practice in the computational era

BACKGROUND

To investigate the accuracy of qualitative reporting of conventional magnetic resonance imaging (MRI) in the classification of paediatric brain tumours.

METHODS

Preoperative MRI reports of 608 children prior to resection or biopsy of an intracranial lesion were retrospectively reviewed. A total of 550 children had complete radiological and histopathological notes, thereby reaching our inclusion criteria. Concordance between MRI report and final histopathological diagnosis was assessed using an established lexicon derived from the WHO 2016 classification of CNS tumours. Levels of agreement based on cellular origin, tumour type, and tumour grade were evaluated. Diagnostic accuracy, sensitivity, specificity, confidence intervals, and positive and negative predictive values were calculated.

RESULTS

Diagnostic accuracy differed significantly between tumour types and tumour grades. Sensitivities were highest for ependymomas and sellar, pituitary, pineal, and cranial and/or paraspinal nerve tumours (range 80.65-100%). Sensitivity was slightly lower for astrocytic gliomas, oligodendrogliomas, and choroid plexus, neuronal, mixed neuronal-glial, embryonal, and histiocytic tumours (range 63.33-79.59%). Low sensitivities were noted for meningiomas and mesenchymal non-meningothelial, melanocytic, and germ cell tumours (range 0-56.25%). The most correct tumour type predictions were made in the posterior fossa whilst the most incorrect predictions were made in the lobar regions, pineal/tectal plate area, and the supratentorial ventricles.

CONCLUSIONS

This is the largest published series investigating the predictive accuracy of MRI in paediatric brain tumours. We show that diagnostic accuracy varies greatly by tumour type and location. Looking forward, we should develop and leverage computational methods to improve accuracy in the tumour types and anatomical locations where qualitative diagnostic accuracy is lower.

The current landscape of immunotherapy for pediatric brain tumors

Pediatric central nervous system tumors are the most common solid malignancies in childhood, and aggressive therapy often leads to long-term sequelae in survivors, making these tumors challenging to treat. Immunotherapy has revolutionized prospects for many cancer types in adults, but the intrinsic complexity of treating pediatric patients and the scarcity of clinical studies of children to inform effective approaches have hampered the development of effective immunotherapies in pediatric settings. Here, we review recent advances and ongoing challenges in pediatric brain cancer immunotherapy, as well as considerations for efficient clinical translation of efficacious immunotherapies into pediatric settings.

Global molecular alterations involving recurrence or progression of pediatric brain tumors

BACKGROUND

We aimed to identify molecular changes in recurrent or progressive pediatric brain tumors, as compared to the corresponding initial tumors from the same patients, using genomic, transcriptomic, and proteomic data from a unique and large cohort of 55 patients and 63 recurrent or progressive tumors from the Children's Brain Tumor Tissue Consortium, representing various histologic types.

METHODS

We carried out paired analyses for each gene between recurrent/progressive and initial tumor groups, using RNA-sequencing and mass spectrometry-based proteomic data. By whole-genome sequencing (WGS) analysis, we also examined somatic DNA events for a set of cancer-associated genes.

RESULTS

Of 44 patients examined by WGS, 35 involved at least one cancer-associated gene with a somatic alteration event in a recurrent or progressive tumor that was not present in the initial tumor, including genes NF1, CDKN2A, CCND2, EGFR, and MYCN. By paired analysis, 68 mRNA transcripts were differentially expressed in recurrent/progressive tumors with p<0.001, and these genes could predict patient outcomes in an independent set of pediatric brain tumors. Gene transcript-level associations with recurrence or progression were enriched for protein-level associations. There was a significant overlap in results from pediatric brain tumors and results from adult brain tumors from The Cancer Genome Atlas. Unsupervised analysis defined five subsets of recurrent or progressive tumors, with differences in gene expression and overall patient survival.

CONCLUSIONS

Our study uncovers genes showing consistent expression differences in recurrent or progressive tumors. These genes may provide molecular clues as to processes or pathways underlying more aggressive pediatric brain tumors.

Artificial Intelligence Applications in Pediatric Brain Tumor Imaging: A Systematic Review

OBJECTIVE

Artificial intelligence (AI) has facilitated the analysis of medical imaging given increased computational capacity and medical data availability in recent years. Although many applications for AI in the imaging of brain tumors have been proposed, their potential clinical impact remains to be explored. A systematic review was performed to examine the role of AI in the analysis of pediatric brain tumor imaging.

METHODS

PubMed, Embase, and Scopus were searched for relevant articles up to January 27, 2021.

RESULTS

Literature search identified 298 records, of which 22 studies were included. The most commonly studied tumors were posterior fossa tumors including brainstem glioma, ependymoma, medulloblastoma, and pilocytic astrocytoma (15, 68%). Tumor diagnosis was the most frequently performed task (14, 64%), followed by tumor segmentation (3, 14%) and tumor detection (3, 14%). Of the 6 studies comparing AI to clinical experts, 5 demonstrated superiority of AI for tumor diagnosis. Other tasks including tumor segmentation, attenuation correction of positron emission tomography scans, image registration for patient positioning, and dose calculation for radiotherapy were performed with high accuracy comparable with clinical experts. No studies described use of the AI tool in routine clinical practice.

CONCLUSIONS

AI methods for analysis of pediatric brain tumor imaging have increased exponentially in recent years. However, adoption of these methods in clinical practice requires further characterization of validity and utility. Implementation of these methods may streamline clinical workflows by improving diagnostic accuracy and automating basic imaging analysis tasks.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Non-proliferative and Proliferative Lesions of the Non-human Primate (M. fascicularis)

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the nonhuman primate used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Machine Assist for Pediatric Posterior Fossa Tumor Diagnosis: A Multinational Study

BACKGROUND

Clinicians and machine classifiers reliably diagnose pilocytic astrocytoma (PA) on magnetic resonance imaging (MRI) but less accurately distinguish medulloblastoma (MB) from ependymoma (EP). One strategy is to first rule out the most identifiable diagnosis.

OBJECTIVE

To hypothesize a sequential machine-learning classifier could improve diagnostic performance by mimicking a clinician's strategy of excluding PA before distinguishing MB from EP.

METHODS

We extracted 1800 total Image Biomarker Standardization Initiative (IBSI)-based features from T2- and gadolinium-enhanced T1-weighted images in a multinational cohort of 274 MB, 156 PA, and 97 EP. We designed a 2-step sequential classifier - first ruling out PA, and next distinguishing MB from EP. For each step, we selected the best performing model from 6-candidate classifier using a reduced feature set, and measured performance on a holdout test set with the microaveraged F1 score.

RESULTS

Optimal diagnostic performance was achieved using 2 decision steps, each with its own distinct imaging features and classifier method. A 3-way logistic regression classifier first distinguished PA from non-PA, with T2 uniformity and T1 contrast as the most relevant IBSI features (F1 score 0.8809). A 2-way neural net classifier next distinguished MB from EP, with T2 sphericity and T1 flatness as most relevant (F1 score 0.9189). The combined, sequential classifier was with F1 score 0.9179.

CONCLUSION

An MRI-based sequential machine-learning classifiers offer high-performance prediction of pediatric posterior fossa tumors across a large, multinational cohort. Optimization of this model with demographic, clinical, imaging, and molecular predictors could provide significant advantages for family counseling and surgical planning.

Brain and Spinal Cord Tumors in Children

This article provides general principles of managing children with central nervous system tumors. The distribution, diagnostic work-up, and key principles of treatment are reviewed, and special circumstances that may be encountered by pediatricians in the community are discussed.

Immunosuppression in Medulloblastoma: Insights into Cancer Immunity and Immunotherapy

OPINION STATEMENT

Medulloblastoma (MB) is the most common pediatric brain malignancy, with a 5-year overall survival (OS) rate of around 65%. The conventional MB treatment, comprising surgical resection followed by irradiation and adjuvant chemotherapy, often leads to impairment in normal body functions and poor quality of life, especially with the increased risk of recurrence and subsequent development of secondary malignancies. The development and progression of MB are facilitated by a variety of immune-evading mechanisms such as the secretion of immunosuppressive molecules, activation of immunosuppressive cells, inhibition of immune checkpoint molecules, impairment of adhesive molecules, downregulation of the major histocompatibility complex (MHC) molecules, protection against apoptosis, and activation of immunosuppressive pathways. Understanding the tumor-immune relationship in MB is crucial for effective development of immune-based therapeutic strategies. In this comprehensive review, we discuss the immunological aspect of the brain, focusing on the current knowledge tackling the mechanisms of MB immune suppression and evasion. We also highlight several key immunotherapeutic approaches developed to date for the treatment of MB.

Postoperative facial palsy after pediatric posterior fossa tumor resection

OBJECTIVE

Facial palsy can be caused by masses within the posterior fossa and is a known risk of surgery for tumor resection. Although well documented in the adult literature, postoperative facial weakness after posterior fossa tumor resection in pediatric patients has not been well studied. The objective of this work was to determine the incidence of postoperative facial palsy after tumor surgery, and to investigate clinical and radiographic risk factors.

METHODS

A retrospective analysis was conducted at a single large pediatric hospital. Clinical, radiographic, and histological data were examined in children who were surgically treated for posterior fossa tumors between May 1, 1994, and June 1, 2011. The incidence of postoperative facial weakness was documented. A multivariate logistic regression model was used to analyze the predictive ability of clinicoradiological variables for facial weakness.

RESULTS

A total of 163 patients were included in this study. The average age at surgery was 7.4 ± 4.7 years, and tumor pathologies included astrocytoma (44%), medulloblastoma (36%), and ependymoma (20%). The lesions of 27 patients (17%) were considered high grade in nature. Thirteen patients (8%) exhibited preoperative symptoms of facial palsy. The overall incidence of postoperative facial palsy was 26% (43 patients), and the incidence of new postoperative facial palsy in patients without preoperative facial weakness was 20% (30 patients). The presence of a preoperative facial palsy had a large and significant effect in univariate analysis (OR 11.82, 95% CI 3.07-45.44, p < 0.01). Multivariate logistic regression identified recurrent operation (OR 4.45, 95% CI 1.49-13.30, p = 0.01) and other preoperative cranial nerve palsy (CNP; OR 3.01, 95% CI 1.24-7.29, p = 0.02) as significant risk factors for postoperative facial weakness.

CONCLUSIONS

Facial palsy is a risk during surgical resection of posterior fossa brain tumors in the pediatric population. The study results suggest that the incidence of new postoperative facial palsy can be as high as 20%. The presence of preoperative facial palsy, an operation for recurrent tumor, and the presence of other preoperative CNPs were found to be significant risk factors for postoperative facial weakness.

Predictive Factors for Postoperative Tracheostomy Requirement in Children Undergoing Surgical Resection of Medulloblastoma

OBJECTIVE

This study is aimed at identifying factors predicting tracheostomy requirement in children diagnosed with a posterior fossa medulloblastoma postoperatively.

METHODS

A retrospective chart review of all patients younger than 18 undergoing medulloblastoma resection from 2012 to 2020 at Namazi Hospital was conducted.

RESULTS

Forty-five patients (26%) needed tracheostomy after the operation. The most common correlates were brainstem compression and absence of gag reflex before operation. Patients who had brainstem compression and infiltration by medulloblastoma, bilateral absence of gag reflex before operation, subtotal resection of the tumor, and postoperative brainstem contusion were more likely to require tracheostomy. No statistically significant difference was observed between males and females and different ages.

CONCLUSIONS

Medulloblastoma is the most common pediatric malignancy. Postoperative ventilator dependency is an important complication in postoperative recovery of patients undergoing medulloblastoma resection. Considering the mutism syndrome with all its question marks by means of predisposing factors, we dealt with a 2-week policy whether there would be any clinical resolution regarding patients' gag reflex. The results show that if we aim for total tumor resection, tracheostomy that is a highly costly and stressful postoperative morbidity can be prevented.

Racial and ethnic disparities among children with primary central nervous system tumors in the US

INTRODUCTION

Primary central nervous system (CNS) tumors are among the most common and lethal types of cancer in children. However, the existence of health disparities in CNS tumors by race or ethnicity remains poorly understood. This systematic review sought to determine whether racial and ethnic disparities in incidence, healthcare access, and survival exist among pediatric patients diagnosed with CNS tumors.

METHODS

A search of MEDLINE, Embase, CINAHL, Web of Science, and Scopus was conducted. Inclusion criteria selected for studies published between January 1, 2005 and July 15, 2020 that focused on pediatric populations in the US, evaluated for potential differences based on racial or ethnic backgrounds, and focused on CNS tumors. A standardized study form was used to collect study information, population of interest, research design, and quality of analysis, sample size, participant demographics, pathology evaluated, and incidence or outcomes observed.

RESULTS

A total of 30 studies were inlcuded. Studies suggest White children may be more likely to be diagnosed with a CNS tumor and Hispanic children to present with advanced-stage disease and have worse outcomes. The degree of influence derived from socioeconomic factors is unclear. This review was limited by few available studies that included race and ethnicity as a variable, the overlap in databases used, and unclear categorization of race and ethnicity.

CONCLUSIONS

This review identified notable and at times contradicting variations in racial/ethnic disparities among children with CNS tumors, suggesting that the extent of these disparities remains largely unknown and prompts further research to improve health equity.

The Assessment of Visual Fields in Infants Using Saccadic Vector Optokinetic Perimetry (SVOP): A Feasibility Study

Purpose

To examine the feasibility of saccadic vector optokinetic perimetry (SVOP), an automated eye tracking perimeter, as a tool for visual field (VF) assessment in infants.

Methods

Thirteen healthy infants aged between 3.5 and 12.0 months were tested binocularly using an adapted SVOP protocol. SVOP uses eye tracking technology to measure gaze responses to stimuli presented on a computer screen. Modifications of SVOP for testing infants included adjusting the fixation target to display a short animation, increasing the stimulus size to equivalent to Goldmann V, and introducing a tiered test pattern strategy. Binocular, single-quadrant confrontation VF testing and Keeler preferential looking cards visual acuity testing was also performed.

Results

Using multiple test attempts when required, all but the youngest infant (12 of 13 [92.3%]) successfully completed a 4-point screening test. Seven infants (53.8%) successfully completed the 12-point test, four (30.8%) successfully completed the 20-point test, and three (23.1%) successfully completed the 40-point test. The effect of multiple test attempts and the complexity of the test pattern (number of test points) on performance was investigated, including test completion rate, percentage of correctly seen stimuli, and average time per tested stimulus.

Conclusions

The modified SVOP test strategy allowed successful assessment of binocular VFs in healthy infants. Future data collection from larger cohorts of infants is needed to derive normative limits of detection and assess accuracy in detecting and monitoring infant VF abnormalities.

Translational Relevance

Eye tracking perimetry may provide a useful method of automated VF assessment in infants.

The diagnostic function of intravoxel incoherent motion for distinguishing between pilocytic astrocytoma and ependymoma

INTRODUCTION

Intravoxel incoherent motion (IVIM) imaging concurrently measures diffusion and perfusion parameters and has potential applications for brain tumor classification. However, the effectiveness of IVIM for the differentiation between pilocytic astrocytoma and ependymoma has not been verified. The aim of this study was to determine the potential diagnostic role of IVIM for the distinction between ependymoma and pilocytic astrocytoma.

METHODS

Between February 2019 and October 2020, 22 children (15 males and 7 females; median age 4 years) with either ependymoma or pilocytic astrocytoma were recruited for this prospective study. IVIM parameters were fitted using 7 b-values (0-1,500 s/mm2), to develop a bi-exponential model. The diffusivity (D), perfusion fraction (f), and pseudo diffusivity (D*) were measured in both tumors and the adjacent normal-appearing parenchyma. These IVIM parameters were compared using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was employed to assess diagnostic performance.

RESULTS

The median D values for ependymoma and pilocytic astrocytoma were 0.87 and 1.25 × 10-3 mm2/s (p < 0.05), respectively, whereas the f values were 0.11% and 0.15% (p < 0.05). The ratios of the median D values for ependymoma and pilocytic astrocytoma relative to the median D values for the adjacent, normal-appearing parenchyma were 1.45 and 2.10 (p < 0.05), respectively. ROC curve analysis found that the D value had the best diagnostic performance for the differentiation between pilocytic astrocytoma and ependymoma, with an area under the ROC curve of 1.

CONCLUSION

IVIM is a beneficial, effective, non-invasive, and endogenous-contrast imaging technique. The D value derived from IVIM was the most essential factor for differentiating ependymoma from pilocytic astrocytoma.

Imaging pitfalls in paediatric posterior fossa neoplastic and non-neoplastic lesions

Paediatric posterior fossa lesions can have much overlap in their clinical and radiological presentation. There are, however, a number of key imaging features that can help the reading radiologist to distinguish tumours from important tumour mimics which are often inflammatory or metabolic entities. This pictorial review provides a number of important cases that proved challenging on imaging and illustrates some common pitfalls when interpreting lesions in the posterior fossa in children. Not everything that is abnormal will be a tumour, but often other causes are overlooked and misinterpreted as tumours, leading to great morbidity for that child. This article highlights some lesions that were mistaken as tumours and will introduce the reader to less commonly seen pathologies which are important to consider on a differential list for this location.

Pediatric brain tumor care in a Sub-Saharan setting: current poise of a precariously loaded dice

OBJECTIVE

To evaluate the current status of pediatric brain tumor (PBT) care and identify determinants and profiles of survival and school attendance.

METHODS

An 8-year institution-based prospective longitudinal study. All cases investigated with neuroimaging and treated were enrolled. Data was analyzed with SPSS (Inc) Chicago IL, USA version 23. Chi Square test, One-way ANOVA and confidence limits were used to evaluate associations at the 95% level of significance. Ethical approval for our study was obtained Health Research Ethics Committee of our hospital.

RESULTS

Among 103 patients enrolled, 92 satisfied our study criteria. There were 45 males and 39 females, M: F = 0.8. The mean age was 9.5 ± 2.1 years 95%CI with a range of 7 months to 16 years. The most common symptom was headache for supratentorial lesions (73%) and gait disturbance (80.2%) for infratentorial lesions. More tumors were supratentorial in location 51 (55.4%), 35 (38.1%) were infratentorial and 6 (6.5%) were transtentorial. Craniopharyngiomas (n = 23), medulloblastomas (n = 22) and astrocytomas (n = 15) were the most common tumors. Hemoglobin genotype (AA and AS) had some influence on tumor phenotype FT, P = 0.033. 76 cases were microsurgically resected while 16 patients were treated with radiotherapy alone. The 30-day mortality for operated cases is 7.2 ± 0.7%. Overall 1-year and 5-year survival was 66.7 and 52.3%, respectively. School attendance, performance and outcome varied among treatment subgroups.

CONCLUSION

Survival profile in this series suggests some improvement in comparison to previous studies from our region, Hemoglobin genotype profiles may signature paediatric brain tumor phenotypes in our setting.

Pediatric Low-Grade Gliomas

Brain tumors constitute the largest source of oncologic mortality in children and low-grade gliomas are among most common pediatric central nervous system tumors. Pediatric low-grade gliomas differ from their counterparts in the adult population in their histopathology, genetics, and standard of care. Over the past decade, an increasingly detailed understanding of the molecular and genetic characteristics of pediatric brain tumors led to tailored therapy directed by integrated phenotypic and genotypic parameters and the availability of an increasing array of molecular-directed therapies. Advances in neuroimaging, conformal radiation therapy, and conventional chemotherapy further improved treatment outcomes. This article reviews the current classification of pediatric low-grade gliomas, their histopathologic and radiographic features, state-of-the-art surgical and adjuvant therapies, and emerging therapies currently under study in clinical trials.

Extraneural metastatic paediatric glioblastoma: Case report and literature review

The incidence of paediatric glioblastoma is uncommon in comparison to their adult counterpart. Even more infrequent are extraneural metastases in glioblastoma. A previously well 14-year-old female presented with progressive right hemiparesis secondary to a left fronto-temporal lobe glioblastoma (WHO IV). She underwent successful gross total resection for her brain tumour. Prior to commencement of her adjuvant treatment, she developed tumour recurrence associated with intra-lesional haemorrhage. Although she underwent a second surgery, the patient developed bilateral malignant pleural effusion secondary to extraneural pulmonary metastases. Early awareness of its existence enables prompt diagnosis for this devastating disease. The authors emphasize the urgent need for international collaborations to work together for children affected by this challenging brain tumour.

Pediatric low-grade glioma in the era of molecular diagnostics

Low grade gliomas are the most frequent brain tumors in children and encompass a spectrum of histologic entities which are currently assigned World Health Organisation grades I and II. They differ substantially from their adult counterparts in both their underlying genetic alterations and in the infrequency with which they transform to higher grade tumors. Nonetheless, children with low grade glioma are a therapeutic challenge due to the heterogeneity in their clinical behavior – in particular, those with incomplete surgical resection often suffer repeat progressions with resultant morbidity and, in some cases, mortality. The identification of up-regulation of the RAS–mitogen-activated protein kinase (RAS/MAPK) pathway as a near universal feature of these tumors has led to the development of targeted therapeutics aimed at improving responses while mitigating patient morbidity. Here, we review how molecular information can help to further define the entities which fall under the umbrella of pediatric-type low-grade glioma. In doing so we discuss the specific molecular drivers of pediatric low grade glioma and how to effectively test for them, review the newest therapeutic agents and their utility in treating this disease, and propose a risk-based stratification system that considers both clinical and molecular parameters to aid clinicians in making treatment decisions.