A multi-disciplinary consensus statement concerning surgical approaches to low-grade, high-grade astrocytomas and diffuse intrinsic pontine gliomas in childhood (CPN Paris 2011) using the Delphi method

Prediction of H3K27M Alteration Status in Brainstem Glioma Using Multi-Shell Diffusion MRI Metrics

BACKGROUND

Multi-shell diffusion characteristics may help characterize brainstem gliomas (BSGs) and predict H3K27M status.

PURPOSE

To identify the diffusion characteristics of BSG patients and investigate the predictive values of various diffusion metrics for H3K27M status in BSG.

STUDY TYPE

Prospective.

POPULATION

Eighty-four BSG patients (median age 10.5 years [IQR 6.8-30.0 years]) were included, of whom 56 were pediatric and 28 were adult patients.

FIELD STRENGTH/SEQUENCE

3 T, multi-shell diffusion imaging.

ASSESSMENT

Diffusion kurtosis imaging and neurite orientation dispersion and density imaging analyses were performed. Age, gender, and diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, radial diffusivity (RD), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis, intracellular volume fraction (ICVF), orientation dispersion index, and isotropic volume fraction (ISOVF), were compared between H3K27M-altered and wildtype BSG patients.

STATISTICAL TESTS

Chi-square test, Mann-Whitney U test, multivariate analysis of variance (MANOVA), step-wise multivariable logistic regression. P-values <0.05 were considered significant.

RESULTS

82.4% pediatric and 57.1% adult patients carried H3K27M alteration. In the whole group, the H3K27M-altered BSGs demonstrated higher FA, AK and lower RD, ISOVF. The combination of age and median ISOVF showed fair performance for H3K27M prediction (AUC = 0.78). In the pediatric group, H3K27M-altered BSGs showed higher FA, AK, MK, ICVF and lower RD, MD, ISOVF. The combinations of median ISOVF, 5th percentile of FA, median MK and median MD showed excellent predictive power (AUC = 0.91). In the adult group, H3K27M-altered BSGs showed higher ICVF and lower RD, MD. The 75th percentile of RD demonstrated fair performance for H3K27M status prediction (AUC = 0.75).

DATA CONCLUSION

Different alteration patterns of diffusion measures were identified between H3K27M-altered and wildtype BSGs, which collectively had fair to excellent predictive value for H3K27M alteration status, especially in pediatric patients.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Surgical options of chiasmatic hypothalamic glioma-a relevant part of therapy in an interdisciplinary approach for tumor control

OBJECTIVE

The extent of resection of pediatric low-grade glioma mostly improves progression-free survival. In chiasmatic hypothalamic glioma (CHG), complete resections are limited due to the relevantly high risk of associated neurological and endocrinological deficits. Still, surgery might have its role in the framework of a multidisciplinary team (MDT) approach. We report our retrospective experience from two centers on surgical options and their impact on long-term outcomes.

METHODS

Medical records of surgically treated pediatric CHG patients between 2004 and 2022 were analyzed. Patient characteristics, surgical interventions, histology, and non-surgical therapy were retrieved together with outcome measures such as visual acuity, endocrine function, and survival.

RESULTS

A total of 63 patients (33 female, NF-1, n = 8) were included. Age at first diagnosis was 4.6 years (range 0.2-16.9) and cohort follow-up was 108 ± 72 months. Twenty patients were surgically treated with a biopsy and 43 patients with debulking at a median age of 6.5 years (range 0.16-16.9). Patients received a median of 2 tumor surgeries (range 1-5). Cyst drainage was accomplished in 15 patients, and 27 patients had ventriculoperitoneal shunt implantation. Non-surgical therapy was given in 69.8%. At the end of follow-up, 74.6% of patients had stable disease. The cohort had a median Karnofsky score of 90 (range 0-100). Four patients died. Hormone substitution was necessary in 30.2%, and visual acuity was impaired in 66% of patients.

CONCLUSION

Pediatric CHG is a chronic disease due to overall high survival with multiple progressions. Surgical therapy remains a key treatment option offering biopsy, limited tumor-debulking, cyst fenestration, and hydrocephalus management in the framework of MDT decision-making. Team experience contributes to reducing possible deficits in this challenging cohort.

Management of patients with diffuse intrinsic pontine glioma in Australia and New Zealand: Australian and New Zealand Children's Haematology/Oncology Group position statement

INTRODUCTION

The main mission of the Australian and New Zealand Children's Haematology and Oncology Group (ANZCHOG) is to develop and facilitate local access to the world's leading evidence-based clinical trials for all paediatric cancers, including brain tumours, as soon as practically possible. Diffuse intrinsic pontine gliomas (DIPGs) - a subset of a larger group of tumours now termed diffuse midline glioma, H3K27-altered (DMG) - are paediatric brain cancers with less than 10% survival at two years. In the absence of any proven curative therapies, significant recent advancements have been made in pre-clinical and clinical research, leading many to seek integration of novel therapies early into standard practice. Despite these innovative therapeutic approaches, DIPG remains an incurable disease for which novel surgical, imaging, diagnostic, radiation and systemic therapy approaches are needed.

MAIN RECOMMENDATIONS

All patients with DIPG should be discussed in multidisciplinary neuro-oncology meetings (including pathologists, neuroradiologists, radiation oncologists, neurosurgeons, medical oncologists) at diagnosis and at relapse or progression. Radiation therapy to the involved field remains the local and international standard of care treatment. Proton therapy does not yield a superior survival outcome compared with photon therapy and patients should undergo radiation therapy with the available modality (photon or proton) at their treatment centre. Patients may receive concurrent chemotherapy or radiation-sensitising agents as part of a clinical trial. Biopsy should be offered to facilitate consideration of experimental therapies and eligibility for clinical trial participation. After radiation therapy, each patient should be managed individually with either observation or considered for enrolment on a clinical trial, if eligible, after full discussion with the family. Re-irradiation can be considered for progressive disease.

CHANGES IN MANAGEMENT AS A RESULT OF THE GUIDELINE

Every child diagnosed with DIPG should be offered enrolment on a clinical trial where available. Access to investigational drugs without biological rationale outside the clinical trial setting is not supported. In case of potentially actionable target identification with molecular profiling and absence of a suitable clinical trial, rational targeted therapies can be considered through compassionate access programs.

Postoperative hydrocephalus is a high-risk lethal factor for patients with low-grade optic pathway glioma

OBJECTIVES

To explore the prognostic factors of patients with low-grade optic pathway glioma (OPG) and the optimal treatment to reduce the incidence of postoperative hydrocephalus.

PATIENTS AND METHODS

This single-center study retrospectively analyzed data from 66 patients with OPGs who underwent surgery. The patients were followed, and overall survival (OS) and progression-free survival (PFS) were determined. The effects of different treatments on the hydrocephalus of patients were compared.

RESULTS

Postoperative hydrocephalus was identified as a factor to increase the risk of mortality by 1.99-fold (p = .028). And, 5-year survival rate was significantly lower among patients with postoperative hydrocephalus (p = .027). The main factors leading to preoperative hydrocephalus in patients are large tumor volume and invasion into the third ventricle. Gross total resections (GTR) could reduce the risk of long-term hydrocephalus (p = .046). Age younger than 4 years (p = .046) and tumor invasion range/classification (p = .029) are the main factors to reduce the five-year survival rate. Postoperative radiotherapy (RT) and chemotherapy (CT) had no significant effects on OS. Extraventricular drainage (EVD) was not associated with perioperative infection (p = .798 > .05) and bleeding (p = .09 > .05). Compared with 2 stage surgery (external ventricular drainage or ventriculoperitoneal shunt (VPS) was first placed, followed by tumor resection), 1 stage surgery (direct resection of tumor) had no complication increase.

CONCLUSIONS

Postoperative hydrocephalus is mostly obstructive hydrocephalus, and it is an important factor that reduces the OS of patients with low-grade OPGs. Surgery to remove the tumor to the greatest extent improves cerebrospinal fluid circulation is effective at reducing the incidence postoperative hydrocephalus. For patients whose ventricles are still dilated after surgery, in addition to considering poor ventricular compliance, they need to be aware of the persistence and progression of hydrocephalus.

Adaption of neurosurgical resection patterns for pediatric low-grade glioma spanning two decades-Report from the German LGG-studies 1996-2018

INTRODUCTION

Neurosurgery is considered the mainstay of treatment for pediatric low-grade glioma (LGG); the extent of resection determines subsequent stratification in current treatment protocols. Yet, surgical radicality must be balanced against the risks of complications that may affect long-term quality of life. We investigated whether this consideration impacted surgical resection patterns over time for patients of the German LGG studies.

PATIENTS AND METHODS

Four thousand two hundred and seventy pediatric patients from three successive LGG studies (median age at diagnosis 7.6 years, neurofibromatosis (NF1) 14.7%) were grouped into 5 consecutive time intervals (TI1-5) for date of diagnosis and analyzed for timing and extent of first surgery with respect to tumor site, histology, NF1-status, sex, and age.

RESULTS

The fraction of radiological LGG diagnoses increased over time (TI1 12.6%; TI5 21.7%), while the extent of the first neurosurgical intervention (3440/4270) showed a reduced fraction of complete/subtotal and an increase of partial resections from TI1 to TI5. Binary logistic regression analysis for the first intervention within the first year following diagnosis confirmed the temporal trends (p < 0.001) and the link with tumor site for each extent of resection (p < 0.001). Higher age is related to more complete resections in the cerebellum and cerebral hemispheres.

CONCLUSIONS

The declining extent of surgical resections over time was unrelated to patient characteristics. It paralleled the evolution of comprehensive treatment algorithms; thus, it may reflect alignment of surgical practice to recommendations in respect to age, tumor site, and NF1-status integrated as such into current treatment guidelines. Further investigations are needed to understand how planning, performance, or tumor characteristics impact achieving surgical goals.

The role of surgery for optic pathway gliomas in the era of precision medicine

Optic pathway gliomas (OPGs) represent a unique subset of brain tumours that primarily affect the paediatric population. Traditionally, these tumours are managed conservatively due to their location to and association with vital structures. This article explores the evolving role of surgery in the management of OPGs, particularly in the context of advancements in precision medicine. The advent of targeted therapy, especially for tumours with specific genetic alterations, such as BRAF V600E mutations, has revolutionized the treatment landscape, offering new avenues for patient-specific therapy. However, surgery still plays a crucial role, especially for debulking in cases of hydrocephalus or when standard therapies are ineffective. Advances in surgical techniques, including neuronavigation, endoscopic approaches, and intraoperative neurophysiological monitoring, have enhanced the safety and efficacy of operative interventions. Despite these developments, the complexity of OPGs necessitates a multidisciplinary approach, focusing on long-term outcomes and quality of life. Future research is needed to further elucidate the role of surgery in an era increasingly dominated by molecular genetics and targeted therapies.

Brain stem tumors in children less than 3 months: Clinical and radiologic findings of a rare disease

PURPOSE

Brain stem tumors in children < 3 months at diagnosis are extremely rare. Our aim is to study a retrospective cohort to improve the understanding of the disease course and guide patient management.

METHODS

This is a multicenter retrospective analysis across the European Society for Pediatric Oncology SIOP-E HGG/DIPG Working Group linked centers, including patients with a brainstem tumor diagnosed between 2009 and 2020 and aged < 3 months at diagnosis. Clinical data were collected, and imaging characteristics were analyzed blindly and independently by two neuroradiologists.

RESULTS

Five cases were identified. No patient received any therapy. The epicenter of two tumors was in the medulla oblongata alone and in the medulla oblongata and the pons in three. For patients with tumor in equal parts in the medulla oblongata and the pons (n = 3), the extension at diagnosis involved the spinal cord; for the two patients with the tumor epicenter in the medulla oblongata alone (n = 2), the extension at diagnosis included the pons (n = 2) and the spinal cord (n = 1). Biopsy was performed in one patient identifying a pilocytic astrocytoma. Two patients died. In one patient, autopsy revealed a high-grade glioma (case 3). Three survivors showed either spontaneous tumor regression (n = 2) or stable disease (n = 1). Survivors were followed up for 10, 7, and 0.6 years, respectively. One case had the typical imaging characteristics of a dorsal exophytic low-grade glioma.

CONCLUSIONS

No patient fulfilled the radiologic criteria defining a high-grade glioma. Central neuroradiological review and biopsy may provide useful information regarding the patient management.

Endoscopic debulking canalization for optic pathway glioma with obstructive hydrocephalus

Optic pathway gliomas (OPGs) are benign tumors that can stop growing or even shrink. In recent years, surgical resection has not been considered the first-line treatment because of its high risk of complications. Chemotherapy is the mainstay of treatment for growing OPGs. Surgical treatment for OPGs with obstructive hydrocephalus is required. Ventriculoperitoneal shunting is effective for all types of hydrocephalus. However, long-term management is required, especially in pediatric cases, and there is a risk of shunt-related complications over a long lifespan. Debulking surgery for OPGs allows us to avoid shunt placement by creating a waterway and releasing the hydrocephalus. To reduce the surgical risk and invasiveness, we used an endoscopic canalization technique with a small-diameter cylinder. In this article, we present a case of endoscopic canalization of an obstructive hydrocephalus caused by OPGs in a 14-year-old female to illustrate our surgical technique.(Trial registration Registry name and number: Efficacy and safety of the neuro-endoscopic treatment for brain tumors (2019-0254)).

Posterior fossa tumors in children: current insights

While in adults most intracranial tumors develop around the cerebral hemispheres, 45 to 60% of pediatric lesions are found in the posterior fossa, although this anatomical region represents only 10% of the intracranial volume. The latest edition of the WHO classification for CNS tumors presented some fundamental paradigm shifts that particularly affected the classification of pediatric tumors, also influencing those that affect posterior fossa. Molecular biomarkers play an important role in the diagnosis, prognosis, and treatment of childhood posterior fossa tumors and can be used to predict patient outcomes and response to treatment and monitor its effectiveness. Although genetic studies have identified several posterior fossa tumor types, differing in terms of their location, cell of origin, genetic mechanisms, and clinical behavior, recent management strategies still depend on uniform approaches, mainly based on the extent of resection. However, significant progress has been made in guiding therapy decisions with biological or molecular stratification criteria and utilizing molecularly targeted treatments that address specific tumor biological characteristics. The primary focus of this review is on the latest advances in the diagnosis and treatment of common subtypes of posterior fossa tumors in children, as well as potential therapeutic approaches in the future.   Conclusion: Molecular biomarkers play a central role, not only in the diagnosis and prognosis of posterior fossa tumors in children but also in customizing treatment plans. They anticipate patient outcomes, measure treatment responses, and assess therapeutic effectiveness. Advances in neuroimaging and treatment have significantly enhanced outcomes for children with these tumors. What is Known: • Central nervous system tumors are the most common solid neoplasms in children and adolescents, with approximately 45 to 60% of them located in the posterior fossa. • Multimodal approaches that include neurosurgery, radiation therapy, and chemotherapy are typically used to manage childhood posterior fossa tumors What is New: • Notable progress has been achieved in the diagnosis, categorization and management of posterior fossa tumors in children, leading to improvement in survival and quality of life.

Sex-related incidence and survival differences in pediatric high-grade glioma subtypes: A population-based cohort study

Not much is known on sex differences in incidence, survival, and treatment characteristics for midline and hemispheric pHGGs. This population-based study confirms previously reported study results that found worse survival outcomes for malignant diffuse gliomas in girls in the age group 0-9 years. Additionally, in our study we pinpoint this difference to girls with midline pHGGs aged 0-4 years. We provide insight in the possible underlying mechanisms contributing to sex survival differences in pHGG patients. With first line treatment having no impact on the higher risk of dying for girls, but age and tumor characteristics having a neutralizing effect. The results of this population-based study serve as a basis for future pre-clinical and clinical studies to further unravel the underlying mechanisms responsible for the survival gap between sexes in midline pHGG.

Neurosurgical morbidity in pediatric supratentorial midline low-grade glioma: Results from the German LGG studies

Surgical resection is a mainstay of treatment for pediatric low-grade glioma (LGG) within all current therapy algorithms, yet associated morbidity is scarcely reported. As supratentorial midline (SML) interventions are particularly challenging, we investigated the frequency of neurosurgical complications/new impairments aiming to identify their risk factors. Records were retrospectively analyzed from 318 patients with SML-LGG from successive German multicenter LGG studies, undergoing surgery between May 1998 and June 2020. Exactly 537 operations (230 resections, 167 biopsies, 140 nontumor procedures) were performed in 318 patients (54% male, median age: 7.6 years at diagnosis, 9.5 years at operation, 11% NF1, 42.5% optic pathway glioma). Surgical mortality rate was 0.93%. Applying the Drake classification, postoperative surgical morbidity was observed following 254/537 (47.3%) and medical morbidity following 97/537 (18.1%) patients with a 40.1% 30-day persistence rate for newly developed neurological deficits (65/162). Neuroendocrine impairment affected 53/318 patients (16.7%), visual deterioration 34/318 (10.7%). Postsurgical morbidity was associated with patient age <3 years at operation, tumor volume ≥80 cm3 , presence of hydrocephalus, complete resection, surgery in centers with less than median reported tumor-related procedures and during the earlier study period between 1998 and 2006, while the neurosurgical approach, tumor location, NF1 status or previous nonsurgical treatment were not. Neurosurgery-associated morbidity was frequent in pediatric patients with SML-LGG undergoing surgery in the German LGG-studies. We identified patient- and institution-associated factors that may increase the risk for complications. We advocate that local multidisciplinary teams consider the planned extent of resection and surgical skills.

The Role of Reirradiation in Childhood Progressive Diffuse Intrinsic Pontine Glioma (DIPG): An Ongoing Challenge beyond Radiobiology

To investigate the clinical impact of multiple courses of irradiation on pediatric patients with progressive diffuse intrinsic pontine glioma (DIPG), we conducted a retrospective case series on three children treated at our institution from 2018 to 2022. All children were candidates to receive systemic therapy with vinorelbine and nimotuzumab. Radiotherapy was administered to a total dose of 54 Gy. At any disease progression, our local tumor board evaluated the possibility of offering a new course of radiotherapy. To determine feasibility and assess toxicity rates, all children underwent clinical and hematological evaluation both during and after the treatment. To assess efficacy, all children performed contrast-enhanced MRI almost quarterly after the end of the treatment. In all children, following any treatment course, neurological improvement (>80%) was associated with a radiological response (41.7-46%). The longest overall survival (24 months) was observed in the child who underwent three courses of radiotherapy, without experiencing significant side effects. Even though it goes beyond the understanding of conventional radiobiology, first and second reirradiation in pediatric patients with progressive DIPG may represent a feasible and safe approach, capable of increasing overall survival and disease-free survival in selected patients and improving their quality of life.

Prognostic Indicators for H3K27M-Mutant Diffuse Midline Glioma: A Population-Based Retrospective Surveillance, Epidemiology, and End Results Database Analysis

BACKGROUND

Diffuse midline glioma with histone H3K27M mutation (H3K27M DMG) is a recently recognized World Health Organization grade IV glioma with a dismal prognosis. Despite maximal treatment, this high-grade glioma exhibits an estimated median survival of 9-12 months. However, little is known with regards to prognostic risk factors for overall survival (OS) for patients with this malignant tumor. The aim of the present study is to characterize risk factors influencing survival in H3K27M DMG.

METHODS

This is a population-based retrospective study of survival in patients with H3K27M DMG. The Surveillance, Epidemiology, and End Results database was examined from the years 2018 to 2019 and data from 137 patients were collected. Basic demographics, tumor site, and treatments regimens were retrieved. Univariate and multivariable analyses were conducted to assess for factors associated with OS. Nomograms were built based on the results of the multivariable analyses.

RESULTS

Median OS of the entire cohort was 13 months. Patients with infratentorial H3K27M DMG exhibited worse OS compared to their supratentorial counterparts. Any form of radiation treatment resulted in a significantly improved OS. Most combination treatments significantly improved OS with the exception of the surgery plus chemotherapy group. The combination of surgery and radiation had the greatest impact on OS.

CONCLUSIONS

Overall, the infratentorial location of H3K27M DMG portends a worse prognosis compared to their supratentorial counterparts. The combination of surgery and radiation had the greatest impact on OS. These data highlight the survival benefit in utilizing a multimodal treatment approach for H3K27M DMG.

Feasibility of probe washing after stereotactic needle biopsy as a novel technique for developing cell lines and xenografts of H3 K27-altered diffuse midline gliomas

H3 K27-altered diffuse midline gliomas (DMGs) are frequently biopsied to obtain tissue diagnosis, inform clinical decision-making, and determine clinical trial eligibility. Tissue yield from biopsies is typically low, leaving little material available for research. To advance understanding of disease biology and promote preclinical testing of novel therapeutics, collecting viable cellular material from treatment-naive tumors is of paramount importance. Here, the authors report the feasibility of a practicable technique for creating DMG cell lines and patient-derived xenografts (PDXs) without the need for additional biopsy specimens. Tumor cells are obtained by probe washing immediately after completion of biopsy. Wash fluid is collected, and viable cells are expanded in vitro. Cultured cells are used to establish PDX rodent models. A total of 5 patient samples were collected by this technique. Viable tumor cells were obtained from 3 of the 5 samples, and cell lines suitable for experiments were obtained within 6-8 months. Orthotopic implantation and flank engraftment was successful in 1 of the 3 established cell lines. Animals harboring intracranial tumors were euthanized due to disease burden 6-7 months after stereotactic injection. Flank tumors formed within 4-5 months and were serially passaged. Molecular and tissue analyses confirmed retention of H3 K27M expression and loss of H3 K27me3 in all cell lines and PDXs.

The Present and Future of Optic Pathway Glioma Therapy

Optic pathway gliomas (OPGs) encompass two distinct categories: benign pediatric gliomas, which are characterized by favorable prognosis, and malignant adult gliomas, which are aggressive cancers associated with a poor outcome. Our review aims to explore the established standards of care for both types of tumors, highlight the emerging therapeutic strategies for OPG treatment, and propose potential alternative therapies that, while originally studied in a broader glioma context, may hold promise for OPGs pending further investigation. These potential therapies encompass immunotherapy approaches, molecular-targeted therapy, modulation of the tumor microenvironment, nanotechnologies, magnetic hyperthermia therapy, cyberKnife, cannabinoids, and the ketogenic diet. Restoring visual function is a significant challenge in cases where optic nerve damage has occurred due to the tumor or its therapeutic interventions. Numerous approaches, particularly those involving stem cells, are currently being investigated as potential facilitators of visual recovery in these patients.

Epidemiology, Diagnostic Strategies, and Therapeutic Advances in Diffuse Midline Glioma

Object: Diffuse midline glioma (DMG) is a highly aggressive and lethal brain tumor predominantly affecting children and young adults. Previously known as diffuse intrinsic pontine glioma (DIPG) or grade IV brain stem glioma, DMG has recently been reclassified as "diffuse midline glioma" according to the WHO CNS5 nomenclature, expanding the DMG demographic. Limited therapeutic options result in a poor prognosis, despite advances in diagnosis and treatment. Radiotherapy has historically been the primary treatment modality to improve patient survival. Methods: This systematic literature review aims to comprehensively compile information on the diagnosis and treatment of DMG from 1 January 2012 to 31 July 2023. The review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and utilized databases such as PubMed, Cochrane Library, and SciELO. Results: Currently, molecular classification of DMG plays an increasingly vital role in determining prognosis and treatment options. Emerging therapeutic avenues, including immunomodulatory agents, anti-GD2 CAR T-cell and anti-GD2 CAR-NK therapies, techniques to increase blood-brain barrier permeability, isocitrate dehydrogenase inhibitors, oncolytic and peptide vaccines, are being explored based on the tumor's molecular composition. However, more clinical trials are required to establish solid guidelines for toxicity, dosage, and efficacy. Conclusions: The identification of the H3K27 genetic mutation has led to the reclassification of certain midline tumors, expanding the DMG demographic. The field of DMG research continues to evolve, with encouraging findings that underscore the importance of highly specific and tailored therapeutic strategies to achieve therapeutic success.

Oncolytic virotherapy for the treatment of pediatric brainstem gliomas

Diffuse intrinsic pontine glioma (DIPG) is the most frequent brainstem glioma and the most lethal brain tumor in childhood. Despite transient benefit with radiotherapy, the prognosis of children with this disease remains dismal with severe neurological morbidity and median survival less than 12months. Oncolytic immunovirotherapy is emerging as a potential therapeutic approach in neuro-oncology. The oncolytic adenovirus Delta-24-RGD has shown efficacy in adult patients with recurrent GBM. Our group has demonstrated that Delta-24-RGD has oncolytic activity and triggers immune response in preclinical models of DIPG, and has a synergistic effect with radiotherapy in animal models of this disease. In this scenario, we conducted a first-in-human phase 1 clinical trial to evaluate the safety and efficacy of intratumoral injection of Delta-24-RGD in pediatric patients with newly diagnosed DIPG prior to standard radiotherapy. The study confirmed the feasibility of this treatment with an acceptable safety profile and encouraging efficacy results. Correlative analyses showed a biological activity from Delta-24-RGD in DIPG. Further advanced trials are needed to validate these results. Meanwhile, plenty of opportunities to increase the potential contribution of oncolytic viruses in the management of devastating tumors with no current effective treatment such as DIPG need to be explored and exploited.

Bevacizumab as Single Agent in Children and Teenagers with Optic Pathway Glioma

This is a retrospective study conducted on patients with OPG, aged less than 19 years, treated with bevacizumab as a single agent, since 2010 at IHOPe (Institute of Pediatric Hematology and Oncology). Efficacy of the treatment was evaluated on the tumor response rate on MRI with a centralized review basing upon RAPNO criteria and with visual assessment basing upon a 0.2 log change in the logMAR scale. Thirty-one patients with OPG have been included. From a radiological point of view, best anytime responses were: 1 major response, 6 partial responses, 7 minor responses and 14 stable diseases; achieving disease control in 28 (96%) out of 29 patients. Ophthalmological response was evaluated in 25 patients and disease control was achieved in 22 (88%) out of 25, with 14 steady states and 8 significant improvements. Among patients treated with chemotherapy after the bevacizumab course, nine relapsed and have been retreated with objective responses. Bevacizumab used as single agent seems effective in children and adolescents with OPG. Our work paves the way for a phase II study in which bevacizumab alone could be used as frontline therapy.

H3K27-altered diffuse midline glioma: a paradigm shifting opportunity in direct delivery of targeted therapeutics

INTRODUCTION

Despite much progress, the prognosis for H3K27-altered diffuse midline glioma (DMG), previously known as diffuse intrinsic pontine glioma when located in the brainstem, remains dark and dismal.

AREAS COVERED

A wealth of research over the past decade has revolutionized our understanding of the molecular basis of DMG, revealing potential targetable vulnerabilities for treatment of this lethal childhood cancer. However, obstacles to successful clinical implementation of novel therapies remain, including effective delivery across the blood-brain barrier (BBB) to the tumor site. Here, we review relevant literature and clinical trials and discuss direct drug delivery via convection-enhanced delivery (CED) as a promising treatment modality for DMG. We outline a comprehensive molecular, pharmacological, and procedural approach that may offer hope for afflicted patients and their families.

EXPERT OPINION

Challenges remain in successful drug delivery to DMG. While CED and other techniques offer a chance to bypass the BBB, the variables influencing successful intratumoral targeting are numerous and complex. We discuss these variables and potential solutions that could lead to the successful clinical implementation of preclinically promising therapeutic agents.

A new era for optic pathway glioma: A developmental brain tumor with life-long health consequences

Optic pathway and hypothalamic glioma (OPHG) are low-grade brain tumors that arise from any part of the visual pathways frequently involving the hypothalamus. The tumors grow slowly and present with features driven by their precise anatomical site, their age at presentation and the stage of growth and development of the host neural and orbital bony tissues. Up to 50% of optic pathway glioma arise in association with Neurofibromatosis type 1 (NF1), which affects 1 in 3,000 births and is a cancer predisposition syndrome. As low-grade tumors, they almost never transform to malignant glioma yet they can threaten life when they present under two years of age. The main risks are to threaten vision loss by progressive tumor damage to optic pathways; furthermore, invasion of the hypothalamus can lead to diencephalic syndrome in infancy and hypopituitarism later in life. Progressive cognitive and behavioural dysfunction can occur, as part of NF1 syndromic features and in sporadic cases where large bulky tumors compress adjacent structures and disrupt neuro-hypothalamic pathways. Persistently progressive tumors require repeated treatments to attempt to control vision loss, other focal brain injury or endocrine dysfunction. In contrast tumors presenting later in childhood can be seen to spontaneously arrest in growth and subsequently progress after periods of stability. These patterns are influenced by NF status as well as stages of growth and development of host tissues. The past two decades has seen an expansion in our understanding and knowledge of the clinical and scientific features of these tumors, their modes of presentation, the need for careful visual and endocrine assessment. This influences the decision-making surrounding clinical management with surgery, radiotherapy, chemotherapy and most recently, the potential benefit of molecularly targeted drug therapy. This article, based upon the authors' clinical and research experience and the published literature will highlight advances in approach to diagnosis, the established role of vision loss as justification of treatments and the emerging evidence of endocrine and neurological consequences that need to be incorporated into judgements for case selection for therapy or observation. Consideration is given to the current state of biological evidence justifying current trials of new therapies, the genetic studies of the NF1 gene and the potential for new approaches to OPHG detection and treatment. The outstanding health system priorities from the perspective of children, their parents and health system commissioners or insurers are discussed.

Pediatric low-grade glioma: Targeted therapeutics and clinical trials in the molecular era

pLGGs are a group of tumors for which the era of molecular diagnostics has truly shifted treatment paradigms and patient care. The discovery that this group of tumors is driven by single-gene alterations/fusions in the MAPK pathway has resulted in relatively rapid translation into targeted therapy options for patients with this often chronic disease. This translation has been facilitated through efforts of multiple collaboratives and consortia and has led to the development of clinical trials testing the role of targeted therapies in pLGG. Although these developments represent promise, many questions remain regarding these therapies including their long-term toxicities and their potential effects on the natural history of pLGG.

Early molecular diagnosis of BRAF status drives the neurosurgical management in BRAF V600E-mutant pediatric low-grade gliomas: a case report

BACKGROUND

To date, this is the only report showing with close and consecutive magnetic resonance images the extremely rapid response of two types of pediatric low-grade gliomas (PLGG) to vemurafenib and its impact on the surgical approach.

CASES PRESENTATION

We report two cases of symptomatic PLGG treated with vemurafenib, a BRAF inhibitor: in a 12-year-old girl it was used as first-line medical treatment, reducing the tumor by 45% within a month and stabilizing to 76% after a year; in a 3-year-old boy with no improvement after SIOP LGG 2004 Protocol, vemurafenib induced in only one week a 34% shrinkage and solved the hydrocephalus, avoiding surgical operation. DISCUSSION AND CONCLUSIONS: Our cases demonstrate how an early molecular diagnosis of BRAF mutations through the neurosurgical biopsy is essential to promptly start targeted therapies., whose effect can influence both therapeutic and surgical decisions, hopefully reducing the occurrence of second neurosurgery with associated risks of neurological sequelae.

Management of Optic Pathway Glioma: A Systematic Review and Meta-Analysis

Background: OPG accounts for 3−5% of childhood central nervous system (CNS) tumors and about 2% of pediatric glial lesions. Methods: Article selection was performed by searching PubMed, Web of Science, and Cochrane databases. Results: The pooled mortality rate was 0.12 (95%CI 0.09−0.14). Due to the unrepresentative data, improved and not changed outcomes were classified as favorable outcomes and worsened as unfavorable. Meta-analyses were performed to determine the rate of clinical and radiological favorable outcomes. In terms of visual assessment, the pooled rate of a favorable outcome in chemotherapy, radiotherapy, and surgery was 0.74, 0.81, and 0.65, respectively, and the overall pooled rate of the favorable outcome was 0.75 (95%CI 0.70−0.80). In terms of radiological assessment, the rate of a favorable outcome following chemotherapy, radiotherapy, and surgery was 0.71, 0.74, and 0.67, respectively, and the overall pooled rate of the favorable outcome is 0.71 (95%CI 0.65−0.77). The subgroup analysis revealed no significant difference in the rate of clinical and radiological favorable outcomes between the different treatment modalities (p > 0.05). Conclusion: Our analyses showed that each therapeutic modality represents viable treatment options to achieve remission for these patients.

Targeted therapy for pediatric diffuse intrinsic pontine glioma: a single-center experience

Background:

Diffuse intrinsic pontine glioma (DIPG) is a fatal disease with a median overall survival (OS) of less than 12 months after diagnosis. Radiotherapy (RT) still remains the mainstay treatment. Several other therapeutic strategies have been attempted in the last years without a significant effect on OS. Although radiological imaging is the gold standard for DIPG diagnosis, the urgent need to improve the survival has led to the reconsideration of biopsy with the aim to better understand the molecular profile of DIPG and support personalized treatment.

Methods:

In this study, we present a single-center experience in treating DIPG patients at disease progression combining targeted therapies with standard of care. Biopsy was proposed to all patients at diagnosis or disease progression. First-line treatment included RT and nimotuzumab/vinorelbine or temozolomide. Immunohistochemistry-targeted research included study of mTOR/p-mTOR pathway and BRAFv600E. Molecular analyses included polymerase chain reaction, followed by Sanger sequences and/or next-generation sequencing.

Results:

Based on the molecular profile, targeted therapy was administered in 9 out of 25 patients, while the remaining 16 patients were treated with standard of care. Personalized treatment included inhibition of the PI3K/AKT/mTOR pathway (5/9), PI3K/AKT/mTOR pathway and BRAFv600E (1/9), ACVR1 (2/9) and PDGFRA (1/9); no severe side effects were reported during treatment. Response to treatment was evaluated according to Response Assessment in Pediatric Neuro-Oncology criteria, and the overall response rate within the cohort was 66%. Patients treated with targeted therapies were compared with the control cohort of 16 patients. Clinical and pathological characteristics of the two cohorts were homogeneous. Median OS in the personalized treatment and control cohort was 20.26 and 14.18 months, respectively (p = 0.032). In our experience, the treatment associated with the best OS was everolimus.

Conclusion:

Despite the small simple size of our study, our data suggest a prognostic advantage and a safe profile of targeted therapies in DIPG patients, and we strongly advocate to reconsider the role of biopsy for these patients.

Long-term follow-up of surgical intervention pattern in pediatric low-grade gliomas: report from the German SIOP-LGG 2004 cohort

OBJECTIVE

Neurosurgical treatment is an integral part of the treatment algorithms for pediatric low-grade glioma (LGG), yet patterns of surgical procedures are rarely challenged. The objective of this study was to evaluate surgical treatment patterns in pediatric LGG.

METHODS

The German Societé Internationale d'Oncologie Pédiatrique (SIOP)-LGG 2004 cohort was analyzed to identify relevant patient and tumor characteristics associated with time to death, next surgery, number of resections, and radiological outcome.

RESULTS

A total of 1271 patients underwent 1713 neurosurgical interventions (1 intervention in 947, 2 in 230, 3 in 70, and 4-6 in 24). The median age of the study population was 8.57 years at first surgery, and 46.1% were female. Neurofibromatosis type 1 (NF1) was found in 4.4%, and 5.4% had tumor dissemination. Three hundred fifty-four patients (27.9%) had chemotherapy and/or radiotherapy. The cumulative incidence of second surgery at 10 years was 26%, and was higher for infants, those with spinal and supratentorial midline (SML) tumors, and those with pilomyxoid astrocytomas. The hazard ratio for subsequent surgery was higher given dissemination and noncomplete initial resection, and lower for caudal brainstem and SML tumors. Among 1225 patients with fully documented surgical records and radiological outcome, 613 reached complete remission during the observation period, and 50 patients died. Patients with pilocytic astrocytoma had higher chances for a final complete remission, whereas patients with initial partial or subtotal tumor resection, dissemination, NF1, or primary tumor sites in the spinal cord and SML had lower chances.

CONCLUSIONS

Neurosurgery is a key element of pediatric LGG treatment. In almost 50% of the patients, however, at least some tumor burden will remain during long-term follow-up. This study found that most of these patients reached a stable disease status without further surgeries. Multidisciplinary team decisions must balance the goal of complete resection, risk factors, repeated surgeries, and possible treatment alternatives in a wide range of heterogeneous entities. Procedural details and neurological outcome should be recorded to better assess their impact on long-term outcome.

Neurosurgery for Optic Pathway Glioma: Optimizing Multidisciplinary Management

Optic pathway glioma (OPG) comprises 10% of pediatric brain tumors and 40% of all pediatric low-grade gliomas (pLGGs). While generally considered benign pathologically, many require interventions with chemotherapy, radiation, or targeted therapies. Management has historically foregone tissue diagnosis given the classical clinical/radiographic presentation of these tumors, inability to safely remove the lesions surgically, and efficacy and safety of available chemotherapy options. Furthermore, when considering such aspects as their delicate location, the role of surgery continues to be heavily debated. More recently, however, a greater understanding of the genetic drivers of OPGs has made operative tissue sampling a critical step in management planning, specifically for patients without Neurofibromatosis, Type I (NF1). Given the need for long-term, complex management of pediatric OPGs, it is crucial that a multidisciplinary approach is employed, and the rapidly expanding role of molecular characterization be incorporated into their management.

Accuracy of central neuro-imaging review of DIPG compared with histopathology in the International DIPG Registry

BACKGROUND

Diffuse intrinsic pontine glioma (DIPG) remains a clinico-radiologic diagnosis without routine tissue acquisition. Reliable imaging distinction between DIPG and other pontine tumors with potentially more favorable prognoses and treatment considerations is essential.

METHODS

Cases submitted to the International DIPG registry (IDIPGR) with histopathologic and/or radiologic data were analyzed. Central imaging review was performed on diagnostic brain MRIs (if available) by two neuro-radiologists. Imaging features suggestive of alternative diagnoses included nonpontine origin, <50% pontine involvement, focally exophytic morphology, sharply defined margins, and/or marked diffusion restriction throughout.

RESULTS

Among 286 patients with pathology from biopsy and/or autopsy, 23 (8%) had histologic diagnoses inconsistent with DIPG, most commonly nondiffuse low-grade gliomas and embryonal tumors. Among 569 patients with centrally-reviewed diagnostic MRIs, 40 (7%) were classified as non-DIPG, alternative diagnosis suspected. The combined analysis included 151 patients with both histopathology and centrally-reviewed MRI. Of 77 patients with imaging classified as characteristic of DIPG, 76 (99%) had histopathologic diagnoses consistent with DIPG (infiltrating grade II-IV gliomas). Of 57 patients classified as likely DIPG with some unusual imaging features, 55 (96%) had histopathologic diagnoses consistent with DIPG. Of 17 patients with imaging features suggestive of an alternative diagnosis, eight (47%) had histopathologic diagnoses inconsistent with DIPG (remaining patients were excluded due to nonpontine tumor origin). Association between central neuro-imaging review impression and histopathology was significant (p < 0.001), and central neuro-imaging impression was prognostic of overall survival.

CONCLUSIONS

The accuracy and important role of central neuro-imaging review in confirming the diagnosis of DIPG is demonstrated.

Methodological Challenges of Digital PCR Detection of the Histone H3 K27M Somatic Variant in Cerebrospinal Fluid

Cell-free DNA (cfDNA) in body fluids is invaluable for cancer diagnostics. Despite the impressive potential of liquid biopsies for the diagnostics of central nervous system (CNS) tumors, a number of challenges prevent introducing this approach into routine laboratory practice. In this study, we adopt a protocol for sensitive detection of the H3 K27M somatic variant in cerebrospinal fluid (CSF) by using digital polymerase chain reaction (dPCR). Optimization of the protocol was carried out stepwise, including preamplification of the H3 target region and adjustment of dPCR conditions. The optimized protocol allowed detection of the mutant allele starting from DNA quantities as low as 9 picograms. Analytical specificity was tested using a representative group of tumor tissue samples with known H3 K27M status, and no false-positive cases were detected. The protocol was applied to a series of CSF samples collected from patients with CNS tumors (n = 18) using two alternative dPCR platforms, QX200 Droplet Digital PCR system (Bio-Rad) and QIAcuity Digital PCR System (Qiagen). In three out of four CSF specimens collected from patients with H3 K27M-positive diffuse midline glioma, both platforms allowed detection of the mutant allele. The use of ventricular access for CSF collection appears preferential, as lumbar CSF samples may produce ambiguous results. All CSF samples collected from patients with H3 wild-type tumors were qualified as H3 K27M-negative. High agreement of the quantitative data obtained with the two platforms demonstrates universality of the approach.

Essential Management of Pediatric Brain Tumors

Brain tumors are the most common solid tumors in children and are associated with high mortality. The most common childhood brain tumors are grouped as low-grade gliomas (LGG), high grade gliomas (HGG), ependymomas, and embryonal tumors, according to the World Health Organization (WHO). Advances in molecular genetics have led to a shift from pure histopathological diagnosis to integrated diagnosis. For the first time, these new criteria were included in the WHO classification published in 2016 and has been further updated in the 2021 edition. Integrated diagnosis is based on molecular genomic similarities of the tumor subclasses, and it can better explain the differences in clinical courses of previously histopathologically identical entities. Important advances have also been made in pediatric neuro-oncology. A growing understanding of the molecular-genetic background of tumorigenesis has improved the diagnostic accuracy. Re-stratification of treatment protocols and the development of targeted therapies will significantly affect overall survival and quality of life. For some pediatric tumors, these advances have significantly improved therapeutic management and prognosis in certain tumor subgroups. Some therapeutic approaches also have serious long-term consequences. Therefore, optimized treatments are greatly needed. Here, we discuss the importance of multidisciplinary collaboration and the role of (pediatric) neurosurgery by briefly describing the most common childhood brain tumors and their currently recognized molecular subgroups.

Combining multi-site magnetic resonance imaging with machine learning predicts survival in pediatric brain tumors

Brain tumors represent the highest cause of mortality in the pediatric oncological population. Diagnosis is commonly performed with magnetic resonance imaging. Survival biomarkers are challenging to identify due to the relatively low numbers of individual tumor types. 69 children with biopsy-confirmed brain tumors were recruited into this study. All participants had perfusion and diffusion weighted imaging performed at diagnosis. Imaging data were processed using conventional methods, and a Bayesian survival analysis performed. Unsupervised and supervised machine learning were performed with the survival features, to determine novel sub-groups related to survival. Sub-group analysis was undertaken to understand differences in imaging features. Survival analysis showed that a combination of diffusion and perfusion imaging were able to determine two novel sub-groups of brain tumors with different survival characteristics (p < 0.01), which were subsequently classified with high accuracy (98%) by a neural network. Analysis of high-grade tumors showed a marked difference in survival (p = 0.029) between the two clusters with high risk and low risk imaging features. This study has developed a novel model of survival for pediatric brain tumors. Tumor perfusion plays a key role in determining survival and should be considered as a high priority for future imaging protocols.

Remission of Pediatric Diffuse Intrinsic Pontine Glioma: Case Report and Review of the Literature

Background

Diffuse midline glioma (DMG) is one of the most aggressive pediatric tumors. Approximately 60% of pediatric DMG patients die within the first year of diagnosis. Complete clinical and radiological remission of DMG is extremely rare. The objective of this study was to describe a case of remission of pediatric DMG and to compare with similar cases published so far.

Results

DMG was diagnosed in a 2-year-old girl who presented with brainstem and increased intracranial pressure manifestations. Ventriculoperitoneal shunt and chemotherapy-based treatment were offered. From the diagnosis, in spite of progressive enlargement of the tumoral lesion, her clinical condition improved remarkably. After the end of chemotherapy, progressive and gradual imagiological improvements occurred. At the end of the 60th month of follow-up, she was asymptomatic with total remission. Six pediatric DMG cases, from birth to the age of 3, in whom remission occurred were found in the literature. Histology sample was available in two of them (fibrillary astrocytoma-WHO Grade II and anaplastic astrocytoma-WHO Grade III). None received chemotherapy or radiotherapy.

Conclusion

Remission of pediatric DMG is extremely rare and reinforces the biological heterogeneity of the tumor. In the absence of reliable predictors of prognosis, offering the best supportive treatment, including neurosurgical interventions should be considered in similar cases.

Comparison of two surgical methods for the treatment of optic pathway gliomas in the intraorbital segment: an analysis of long-term clinical follow-up, which evaluates the surgical outcomes

BACKGROUND

This study analyzes two kinds of surgical methods for the treatment of optic pathway gliomas (OPGs) in the intraorbital segment, as well as the surgical outcomes of OPGs.

METHODS

The clinical data of 86 patients with OPGs treated in our center was analyzed retrospectively, and the clinical symptoms, treatment methods, and follow-up results were recorded.

RESULTS

For OPGs in the intraorbital segment, the optic nerve sheath incision was performed to remove a tumor while retaining the optic nerve sheath in Group 1 (n=36). The optic nerve sheath and the tumor were simultaneously removed without retaining the optic nerve sheath in group 2 (n=50). The effects of the design of the surgical methods on the post-surgical outcome are: One patient (1/36, 2.8%) had recurrence in Group 1 and one patient (1/50, 2.0%) had recurrence in group 2. The differences in the surgical outcomes of the two groups regarding exophthalmos, conjunctiva swelling, eye movement disorder, and ptosis were found to be statistically significant (P<0.05). Compared with group 2, the surgical outcomes in the postoperative phase of Group 1 were more satisfactory.

CONCLUSIONS

The two surgical methods do not increase the recurrence rate of tumors. The resection of OPGs through an optic nerve sheath incision was found to be an ideal surgical method for reducing complications in the postoperative phase and for providing better surgical outcomes.

Doubling Recruitment of Pediatric Low-grade Glioma within Two Decades does not change Outcome - Report from the German LGG Studies

BACKGROUND

Successive multicenter studies for pediatric low-grade glioma (LGG) in Germany were accompanied by a doubling of annual recruitment over 2 decades. We investigated whether this increase conveyed a change of epidemiologic characteristics or survival.

METHODS AND RESULTS

Participating centers reported 4634 patients with the radiologic/histologic diagnosis of LGG (1996-2018), rising from 109 to 278/year. Relating these numbers to all pediatric CNS tumors registered at the German Childhood Cancer Registry, the LGG fraction and annual crude incidence rates increased (32% to 51%; 0.94 to 2.12/100,000 children/adolescents<15 years). The consecutive LGG studies recruited 899 (HIT-LGG 1996), 1592 (SIOP-LGG 2004), and 1836 (LGG-registry) patients with similar distribution of tumor-sites, histology, and dissemination. 5-year overall survival was 96%-98% at median observation time of 8.1 years. Acknowledging unequal follow-up periods, 589/899 (66%), 1089/1582 (69%), and 1387/1836 (76%) patients remained under observation, while 1252/4317 received adjuvant treatment with decreasing frequency of front-line radiotherapy from 16% to 5%.

CONCLUSION

Pediatric LGG incidence rates in Germany are now comparable to other European countries. The rise in patient numbers followed implementation of standard-of-care treatment protocols, but did not result in relevant changes of epidemiologic or clinical parameters or survival. Shifts in patient distribution between treatment arms reflect growing acceptance of the LGG therapy algorithm.

HINTERGRUND

In den vergangenen 20 Jahren hat sich die jährliche Patientenrekrutierung in den aufeinanderfolgenden multizentrischen Studien für pädiatrische niedrig-gradige Gliome (LGG) in Deutschland verdoppelt. Wir haben untersucht, ob sich mit dieser Zunahme auch epidemiologische Merkmale oder das Überleben verändert haben.

METHODIK UND ERGEBNISSE

Zwischen 1996 und 2018 meldeten die teilnehmenden Zentren insgesamt 4634 Patienten mit der radiologischen/histologischen Diagnose eines LGG. Die Zahl stieg von anfangs 109 bis 278 Patienten pro Jahr. Gleichzeitig stieg der Anteil der LGGs an allen am Deutschen Kinderkrebsregister gemeldeten pädiatrischen Hirntumoren von 32 auf 51%, die jährliche Inzidenz erhöhte sich von 0,94 auf 2,12/100 000 Kinder/Jugendliche<15 Jahre. Die aufeinanderfolgenden LGG-Studien rekrutierten 899 (HIT-LGG 1996), 1592 (SIOP-LGG 2004) und 1836 (LGG-Register) Patienten mit vergleichbarer Verteilung von Tumorsitz, Histologie und Disseminierung. Das 5-Jahres-Überleben lag bei einer medianen Nachbeobachtungszeit von 8,1 Jahren zwischen 96 und 98%. Unter Berücksichtigung der ungleich langen Follow-up-Zeit wurden 589/899 (65,5%), 1089/1582 (68,8%) und 1387/1836 (75,5%) Patienten bislang beobachtet, während 1252/4317 eine adjuvante Therapie erhielten. Dabei sank der Anteil der primären Radiotherapie von 16 auf 5%.

SCHLUSSFOLGERUNG

Die Rekrutierung pädiatrischer LGG ist dank Implementierung verbindlicher Therapiestandards in Deutschland gestiegen, ohne zu relevanten Veränderungen epidemiologischer oder klinischer Merkmale oder des Überlebens zu führen. Die Inzidenz ist mit anderen europäischen Ländern vergleichbar. Verschiebungen der Patientenzuteilung zwischen den Therapiearmen spiegeln die zunehmende Akzeptanz des LGG-Therapie-Algorithmus wider.

A phase II study of continuous oral mTOR inhibitor everolimus for recurrent, radiographic-progressive neurofibromatosis type 1-associated pediatric low-grade glioma: a Neurofibromatosis Clinical Trials Consortium study

BACKGROUND

Activation of the mammalian target of rapamycin (mTOR) pathway is observed in neurofibromatosis type 1 (NF1) associated low-grade gliomas (LGGs), but agents that inhibit this pathway, including mTOR inhibitors, have not been studied in this population. We evaluate the efficacy of the orally administered mTOR inhibitor everolimus for radiographically progressive NF1-associated pediatric LGGs.

METHODS

Children with radiologic-progressive, NF1-associated LGG and prior treatment with a carboplatin-containing chemotherapy were prospectively enrolled on this phase II clinical trial to receive daily everolimus. Whole blood was analyzed for everolimus and markers of phosphatidylinositol-3 kinase (PI3K)/mTOR pathway inhibition. Serial MRIs were obtained during treatment. The primary endpoint was progression-free survival at 48 weeks.

RESULTS

Twenty-three participants (median age, 9.4 y; range, 3.2-21.6 y) were enrolled. All participants were initially evaluable for response; 1 patient was removed from study after development of a malignant peripheral nerve sheath tumor. Fifteen of 22 participants (68%) demonstrated a response, defined as either shrinkage (1 complete response, 2 partial response) or arrest of tumor growth (12 stable disease). Of these, 10/15 remained free of progression (median follow-up, 33 mo). All remaining 22 participants were alive at completion of therapy. Treatment was well tolerated; no patient discontinued therapy due to toxicity. Pharmacokinetic parameters and pre-dose concentrations showed substantial between-subject variability. PI3K/mTOR pathway inhibition markers demonstrating blood mononuclear cell mTOR pathway inactivation was achieved in most participants.

CONCLUSION

Individuals with recurrent/progressive NF1-associated LGG demonstrate significant disease stability/shrinkage during treatment with oral everolimus with a well-tolerated toxicity profile. Everolimus is well suited for future consideration as upfront or combination therapy in this patient population.

The Korean Society for Neuro-Oncology (KSNO) Guideline for Adult Diffuse Midline Glioma: Version 2021.1

BACKGROUND

There have been no guidelines for the management of adult patients with diffuse midline glioma (DMG), H3K27M-mutant in Korea since the 2016 revised WHO classification newly defined this disease entity. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for DMG since 2019.

METHODS

The Working Group was composed of 27 multidisciplinary medical experts in Korea. References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. As 'diffuse midline glioma' was recently defined, and there was no international guideline, trials and guidelines of 'diffuse intrinsic pontine glioma' or 'brain stem glioma' were thoroughly reviewed first.

RESULTS

The core contents are as follows. The DMG can be diagnosed when all of the following three criteria are satisfied: the presence of the H3K27M mutation, midline location, and infiltrating feature. Without identification of H3K27M mutation by diagnostic biopsy, DMG cannot be diagnosed. For the primary treatment, maximal safe resection should be considered for tumors when feasible. Radiotherapy is the primary option for tumors in case the total resection is not possible. A total dose of 54 Gy to 60 Gy with conventional fractionation prescribed at 1-2 cm plus gross tumor volume is recommended. Although no chemotherapy has proven to be effective in DMG, concurrent chemoradiotherapy (± maintenance chemotherapy) with temozolomide following WHO grade IV glioblastoma's protocol is recommended.

CONCLUSION

The detection of H3K27M mutation is the most important diagnostic criteria for DMG. Combination of surgery (if amenable to surgery), radiotherapy, and chemotherapy based on comprehensive multidisciplinary discussion can be considered as the treatment options for DMG.

Treatment with endoscopic transnasal resection of hypothalamic pilocytic astrocytomas: a single-center experience

Backgrounds

Pilocytic astrocytomas (PAs) are World Health Organization (WHO) grade I tumors, which are relatively common, and are benign lesions in children. PAs could originate from the cerebellum, optic pathways, and third ventricular/hypothalamic region. Traditional various transcranial routes are used for hypothalamic PAs (HPAs). However, there are few studies on hypothalamic PAs treated through the endoscopic endonasal approach (EEA). This study reports the preliminary experience of the investigators and results with HPAs via expanded EEAs.

Methods

All patients with HPAs, undergone EEA in our hospital from 2017 to 2019, were retrospectively reviewed. The demographic data, clinical symptoms, complications, skull base reconstruction, prognosis, and endocrinological data were all recorded and analyzed in detail.

Results

Finally, five female patients were enrolled. The average age of patients was 28.6 ± 14.0. All patients had complaints about their menstrual disorder. One patient had severe bilateral visual impairment. Furthermore, only one patient suffered from severe headache due to acute hydrocephalus, although there were four patients with headache or dizziness. Four cases achieved gross-total resection, and one patient achieved subtotal resection. Furthermore, there was visual improvement in one patient (case 5), and postoperative worsening of vision in one patient (case 4). However, only one patient had postoperative intracranial infection. None of the patients experienced a postoperative CSF leak, and in situ bone flap (ISBF) techniques were used for two cases for skull base repair. In particular, ISBF combined with free middle turbinate mucosal flap was used for case 5. After three years of follow-up, three patients are still alive, two patients had no neurological or visual symptoms, or tumor recurrence, and one patient had severe hypothalamic dysfunction. Unfortunately, one patient died of severe postoperative hypothalamus reaction, which presented with coma, high fever, diabetes insipidus, hypernatremia and intracranial infection. The other patient died of recurrent severe pancreatitis at one year after the operation.

Conclusion

Although the data is still very limited and preliminary, EEA provides a direct approach to HPAs with acceptable prognosis in terms of tumor resection, endocrinological and visual outcomes. ISBF technique is safe and reliable for skull base reconstruction.

Diffuse intrinsic pontine glioma: current insights and future directions

Diffuse intrinsic pontine glioma (DIPG) is a lethal pediatric brain tumor and the leading cause of brain tumor–related death in children. As several clinical trials over the past few decades have led to no significant improvements in outcome, the current standard of care remains fractionated focal radiation. Due to the recent increase in stereotactic biopsies, tumor tissue availabilities have enabled our advancement of the genomic and molecular characterization of this lethal cancer. Several groups have identified key histone gene mutations, genetic drivers, and methylation changes in DIPG, providing us with new insights into DIPG tumorigenesis. Subsequently, there has been increased development of in vitro and in vivo models of DIPG which have the capacity to unveil novel therapies and strategies for drug delivery. This review outlines the clinical characteristics, genetic landscape, models, and current treatments and hopes to shed light on novel therapeutic avenues and challenges that remain.

MRI-based diagnosis and treatment of pediatric brain tumors: is tissue sample always needed?

Traditional management of newly diagnosed pediatric brain tumors (PBTs) consists of cranial imaging, typically magnetic resonance imaging (MRI), and is frequently followed by tissue diagnosis, through either surgical biopsy or tumor resection. Therapy regimes are typically dependent on histological diagnosis. To date, many treatment regimens are based on molecular biology. The scope of this article is to discuss the role of diagnosis and further treatment of PBTs based solely on MRI features, in light of the latest treatment protocols. Typical MRI findings and indications for surgical biopsy of these lesions are described.

Optic pathway tumor in children: Toward a new classification for neurosurgical use

OBJECT

Optic pathway tumors (OPT) represent a challenge for pediatric neurosurgeons. Role of surgery is debated due to the high risk of iatrogenic damage, and in lasts decades it lost its importance in favor of chemotherapy. However, in some cases surgery is necessary to make biomolecular and histological diagnosis, to manage intracranial hypertension (IH) and to cooperate with medical therapies in controlling tumor relapse. With the aim to standardize selection of surgical OPT cases, we propose a simple, practical and reproducible classification.

METHODS

We retrospectively analyzed data of 38 patients with OPT treated at our institution (1990-2018). After careful analysis of MRI images, we describe a new classification system. Group 1: lesion limited to one or both optic nerve(s). Group 2: chiasmatic lesions extending minimally to hypothalamus. Group 3: hypothalamo-chiasmatic exophitic lesions invading the third ventricle; they can be further divided on the base of concomitant hydrocephalus. Group 4: hypothalamo-chiasmatic lesions extending widely in lateral direction, toward the temporal or the frontal lobes. Patients' data and adopted treatment are reported and analyzed, also depending on this classification.

RESULTS

Twenty children were operated on for treatment of OPT during the study period. Permanent clinical impairment was noted in 5 (25%) of operated patients, while visual improvement was noted in 1 patient. OS rate was 100% at 5 years, with a median follow up of 9 years (ranging from 2 to 23). Prevalence of intracranial hypertension and proportion of first-line surgical treatment decision were significantly higher in groups 3-4 compared to groups 1-2 (P<0.001 for both tests).

CONCLUSION

Surgery can offer a valuable therapeutic complement for OPT without major risk of iatrogenic damage. Surgery is indispensable in cases presenting with IH, as in groups 3 and 4 lesions. Eligibility of patients to surgery can be based on this new classification system.

Neurofibromatosis 1-associated optic pathway gliomas

BACKGROUND

Optic Pathway Gliomas (OPG) are the most common brain tumor in Neurofibromatosis 1 patients (NF1). They are found along the optic pathway and may involve the optic nerves, chiasm, retro-chiasmatic structures, and the optic radiations. NF1 associate OPG (NF1-OPG) have variable presentation, disease course and response to treatment. The optimal management is patient-specific and should be tailored by a multidisciplinary team. Age, sex, histology, and molecular markers may be important factors in the individualized decision-making process. Chemotherapy is the first-line treatment in cases of progressive tumors, and visual preservation is the main goal of treatment.

PURPOSE

In this paper we will review the disease, practical management, and recent advances of NF1-OPG.

Diffuse infiltrative pontine glioma biopsy in children with neuronavigation, frameless procedure: A single center experience of 10 cases

INTRODUCTION

This study presented pediatric DIPG 's biopsy with frameless Neuronavigation.

PATIENTS AND METHODS

We report our experience about 10 patients who had Diffuse Intrinsic Pontine Glioma between 2014 and 2018. All patients were biopsied with BrainLab Varioguide Neuronavigation®. We always used fusion between specific CT Scan and MRI to selected target, made planning and biopsies. All patients were included in BIOMEDE after scientific and ethic discussions. We always selected a trans-cerebellar trajectory and made same procedure (lot of biopsies at one level). All patients have MRI at J1 to verify site of biopsy and to eliminate complication.

RESULTS

The average age was 8.1 years. Symptoms were common with principally headaches and nystagmus. All biopsies were contributive for histopathological diagnosis and establish molecular profile for molecular study. We have no definitive morbidity and procedure duration was 93minutes in average. All MRI didn't showed intracranial complication after procedure and showed great precision of biopsy compared with the selected target.

DISCUSSION

We reviewed the literature and compare our results with series of DIPG biopsies using stereotactic frame or robotic assisted frameless. It was a safe, accuracy and easiness procedure. We always have histopathological and molecular result to proceed next step of treatment. This modality is an alternative possibility to biopsy very young patients with low morbidity.

Glioneuronal tumors: clinicopathological findings and treatment options

Glioneuronal tumors are very rare CNS neoplasms that demonstrate neuronal differentiation, composed of mixed glial and neuronal cells. The majority of these lesions are low grade and their correct classification is crucial in order to avoid misidentification as ‘ordinary’ gliomas and prevent inappropriate aggressive treatment; nevertheless, precise diagnosis is a challenge due to phenotypic overlap across different histologic subtype. Surgery is the standard of therapeutic approach; literature concerning the benefit of adjuvant treatments is inconclusive and a globally accepted treatment of recurrence does not exist. Targetable mutations in the genes BRAF and FGFR1/2 are recurrently found in these tumors and could take a promising role in future treatment management.

Response assessment in diffuse intrinsic pontine glioma: recommendations from the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group

Optimising the conduct of clinical trials for diffuse intrinsic pontine glioma involves use of consistent, objective disease assessments and standardised response criteria. The Response Assessment in Pediatric Neuro-Oncology working group, consisting of an international panel of paediatric and adult neuro-oncologists, clinicians, radiologists, radiation oncologists, and neurosurgeons, was established to address issues and unique challenges in assessing response in children with CNS tumours. A working group was formed specifically to address response assessment in children and young adults with diffuse intrinsic pontine glioma and to develop a consensus on recommendations for response assessment. Response should be assessed using MRI of brain and spine, neurological examination, and anti-inflammatory or antiangiogenic drugs. Clinical imaging standards are defined. As with previous consensus recommendations, these recommendations will need to be validated in prospective clinical trials.

NF1-like optic pathway gliomas in children: clinical and molecular characterization of this specific presentation

Background

Pediatric neurofibromatosis type 1 (NF1)–associated optic pathway gliomas (OPGs) exhibit different clinico-radiological features, treatment, and outcome compared with sporadic OPGs. While NF1-associated OPGs are caused by complete loss-of-function of the NF1 gene, other genetic alterations of the RAS-MAPK pathway are frequently described in the sporadic cases. We identified a group of patients who presented OPGs with typical radiological features of NF1-associated OPGs but without the NF1 diagnostic criteria. We aim to investigate into the possible molecular mechanisms underlying this “NF1-like” pediatric OPGs presentation.

Methods

We analyzed clinico-radiological features of 16 children with NF1-like OPGs and without NF1 diagnostic criteria. We performed targeted sequencing of the NF1 gene in constitutional samples (n = 16). The RAS-MAPK pathway major genes were sequenced in OPG tumor samples (n = 11); BRAF FISH and IHC analyses were also performed.

Results

In one patient’s blood and tumor samples, we identified a NF1 nonsense mutation (exon 50: c.7285C>T, p.Arg2429*) with ~8% and ~70% VAFs, respectively, suggesting a mosaic NF1 mutation limited to the brain (segmental NF1). This patient presented signs of neurodevelopmental disorder. We identified a somatic alteration of the RAS-MAPK pathway in eight tumors: four BRAF activating p.Val600Glu mutations, three BRAF:KIAA oncogenic fusions, and one putative gain-of-function complex KRAS indel inframe mutation.

Conclusions

NF1-like OPGs can rarely be associated with mosaic NF1 that needs specific constitutional DNA analyses for diagnosis. Further studies are warranted to explore unknown predisposition condition leading to the NF1-like OPG presentation, particularly in patients with the association of a neurodevelopmental disorder.

Clinical, imaging, and molecular analysis of pediatric pontine tumors lacking characteristic imaging features of DIPG

Diffuse intrinsic pontine glioma (DIPG) is most commonly diagnosed based on imaging criteria, with biopsy often reserved for pontine tumors with imaging features not typical for DIPG (atypical DIPG, 'aDIPG'). The histopathologic and molecular spectra of the clinical entity aDIPG remain to be studied systematically. In this study, thirty-three patients with newly diagnosed pontine-centered tumors with imaging inconsistent with DIPG for whom a pathologic diagnosis was subsequently obtained were included. Neoplasms were characterized by routine histology, immunohistochemistry, interphase fluorescence in situ hybridization, Sanger and next-generation DNA/RNA sequencing, and genome-wide DNA methylome profiling. Clinicopathologic features and survival outcomes were analyzed and compared to those of a contemporary cohort with imaging features consistent with DIPG (typical DIPG, 'tDIPG'). Blinded retrospective neuroimaging review assessed the consistency of the initial imaging-based diagnosis and correlation with histopathology. WHO grade II-IV infiltrating gliomas were observed in 54.6% of the cases; the remaining were low-grade gliomas/glioneuronal tumors or CNS embryonal tumors. Histone H3 K27M mutation, identified in 36% of the cases, was the major prognostic determinant. H3 K27M-mutant aDIPG and H3 K27M-mutant tDIPG had similar methylome profiles but clustered separately from diffuse midline gliomas of the diencephalon and spinal cord. In the aDIPG cohort, clinicoradiographic features did not differ by H3 status, yet significant differences in clinical and imaging features were observed between aDIPG without H3 K27M mutation and tDIPG. Neuroimaging review revealed discordance between the classification of aDIPG and tDIPG and did not correlate with the histology of glial/glioneuronal tumors or tumor grade. One patient (3.1%) developed persistent neurologic deficits after surgery; there were no surgery-related deaths. Our study demonstrates that surgical sampling of aDIPG is well-tolerated and provides significant diagnostic, therapeutic, and prognostic implications, and that neuroimaging alone is insufficient to distinguish aDIPG from tDIPG. H3 K27M-mutant aDIPG is epigenetically and clinically similar to H3 K27M-mutant tDIPG.

Accuracy of apparent diffusion coefficient values and magnetic resonance imaging in differentiating suprasellar germinomas from chiasmatic/hypothalamic gliomas

OBJECTIVE

The aim of this study was to differentiate suprasellar germinomas from chiasmatic/hypothalamic gliomas (CHGs) using apparent diffusion coefficient (ADC) values and magnetic resonance imaging (MRI) characteristics.

MATERIALS AND METHODS

A cross-sectional study was conducted on 11 patients with suprasellar germinomas and 11 patients with CHGs who underwent pretreatment MRI. The ADC values (minimum and average ADC values) of the tumors were measured and the MRI characteristics were evaluated.

RESULTS

The average and minimum ADC values of suprasellar germinomas were significantly lower than those of CHGs (p = 0.016 and 0.004 respectively). The selection of 941.15 × 10^-6 mm²/s as a cutoff value of the minimum ADC value was used to differentiate suprasellar germinomas and CHGs; the best results were obtained with area under the curve of 0.889, sensitivity of 87.5%, specificity of 77.8% and accuracy of 82.4%. MRI characteristics suggested the diagnosis of suprasellar germinomas were T2W hypointensity and involvement of pituitary gland and/or stalk. MRI characteristics suggested the diagnosis of CHGs was higher degree of contrast enhancement and presence of macrocysts.

CONCLUSION

ADC values have a role in differentiating suprasellar germinomas and CHGs, especially when imaging findings on conventional MRI are inconclusive. Furthermore, some MRI features are in favor of differentiation between these tumor entities including tumor location, cyst pattern, T2W hypointensity, degree of contrast enhancement, stalk and pituitary gland involvement.

Delphi method to identify expert opinion to support children's cancer referral guidelines

BACKGROUND

The National Institute for Health and Care Excellence (NICE) guidance for referral of children with suspected cancer was first published in 2005 and updated in 2015. The updated version relied on sparse primary care evidence and published without input from key stakeholders, for example, acute general paediatricians and paediatric haematologists/oncologists. This led to a document that fell short as a practical guide for referring physicians managing children with potentially life-threatening conditions. Following discussions between the Children's Cancer and Leukaemia Group (CCLG, the UK multidisciplinary professional body for healthcare professionals caring for children with cancer) and NICE, it was agreed that a practical supplement should be produced for the 2015 guidance. A prerequisite was evidence gathering from tertiary care to balance the existing primary care evidence, and a Delphi consensus method was therefore convened.

METHODS

A CCLG NICE Guidance Committee formulated 25 draft statements for review. The CCLG emailed its paediatric haematologist/oncologist membership (n=179) and 88 responded (49%). To achieve consensus, statements required ≥70% agreement from ≥60% of actual respondents, from the denominator (n=88).

RESULTS

Fifteen of 25 original statements were accepted at the first round of voting. Three of 25 statements where >50% did not support were rejected outright. One statement could not be revised without replicating a previously accepted statement. The six remaining statements were revised and a second round of voting undertaken; all six revised statements were accepted. Overall, 21 of 25 statements (84%) met consensus criteria.

CONCLUSIONS

This expert opinion should help streamline suspected cancer referral in children and help optimise subsequent outcomes.

Combined Targeting of Mutant p53 and Jumonji Family Histone Demethylase Augments Therapeutic Efficacy of Radiation in H3K27M DIPG

Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric brainstem tumor with a 5-year survival of <1%. Up to 80% of the DIPG tumors contain a specific K27M mutation in one of the two genes encoding histone H3 (H3K27M). Furthermore, p53 mutations found in >70–80% of H3K27M DIPG, and mutant p53 status is associated with a decreased response to radiation treatment and worse overall prognosis. Recent evidence indicates that H3K27M mutation disrupts tri-methylation at H3K27 leading to aberrant gene expression. Jumonji family histone demethylases collaborates with H3K27 mutation in DIPG by erasing H3K27 trimethylation and thus contributing to derepression of genes involved in tumorigenesis. Since the first line of treatment for pediatric DIPG is fractionated radiation, we investigated the effects of Jumonji demethylase inhibition with GSK-J4, and mutant p53 targeting/oxidative stress induction with APR-246, on radio-sensitization of human H3K27M DIPG cells. Both APR-246 and GSK-J4 displayed growth inhibitory effects as single agents in H3K27M DIPG cells. Furthermore, both of these agents elicited mild radiosensitizing effects in human DIPG cells (sensitizer enhancement ratios (SERs) of 1.12 and 1.35, respectively; p < 0.05). Strikingly, a combination of APR-246 and GSK-J4 displayed a significant enhancement of radiosensitization, with SER of 1.50 (p < 0.05) at sub-micro-molar concentrations of the drugs (0.5 μM). The molecular mechanism of the observed radiosensitization appears to involve DNA damage repair deficiency triggered by APR-246/GSK-J4, leading to the induction of apoptotic cell death. Thus, a therapeutic approach of combined targeting of mutant p53, oxidative stress induction, and Jumonji demethylase inhibition with radiation in DIPG warrants further investigation.