Optic Pathway Gliomas in Neurofibromatosis Type 1: An Update: Surveillance, Treatment Indications, and Biomarkers of Vision

Genetics and Current Research Models of Mendelian Tumor Predisposition Syndromes with Ocular Involvement

In this review, we aim to provide a survey of hereditable tumor predisposition syndromes with a mendelian inheritance pattern and ocular involvement. We focus our discussion on von Hippel-Lindau disease, neurofibromatosis type 1, NF2-related schwannomatosis, tuberous sclerosis complex, retinoblastoma, and the BAP1 Tumor Predisposition Syndrome. For each of the six diseases, we discuss the clinical presentation and the molecular pathophysiology. We emphasize the genetics, current research models, and therapeutic developments. After reading each disease section, readers should possess an understanding of the clinical presentation, genetic causes and inheritance patterns, and current state of research in disease modeling and treatment.

Identifying patients with neurofibromatosis type 1 related optic pathway glioma using the OMOP CDM

Neurofibromatosis type 1 (NF1) is a rare tumour predisposition syndrome. Optic pathway gliomas (NF1-related OPG) are a well-characterised tumour type. There is great need for tools that can efficiently identify patients with NF1-related OPG at hospitals. Computable phenotypes algorithms can be used to find patients with certain clinical features in an electronic database. We developed computable phenotype algorithms using the Observational Medical Outcome Partnership (OMOP) Common Data Model. We subsequently assessed if these algorithms could identify patients with NF1-related OPG in an electronic health records (EHR) derived database. We created phenotype algorithms based on diagnosis codes, visits, and radiologic procedures. These phenotypes were applied to the EHR-derived database of an academic hospital. To assess the performance of the phenotypes, we calculated the precision, recall, and F2 score against a list of known cases (n = 61), provided by a clinician. To evaluate the ability of the phenotypes to identify additional cases, we manually reviewed the predicted positives of each phenotype algorithm. The phenotype algorithm based on the diagnosis codes 'Neurofibromatosis syndrome' and 'Neoplasm of optic nerve' performed best (precision = 1.000, recall = 0.614, F2-score = 0.665). The phenotype 'Neurofibromatosis syndrome and three or more Ophthalmology visits and one or more MRI of brain' performed best of the phenotypes based on visits and radiologic procedures (precision = 0.489, recall = 0.511, F2-score = 0.507). Generally, increased precision came at the cost of a decrease in recall. Following review of the predicted positives of each phenotype, 27 additional cases were identified. OMOP computable phenotype algorithms successfully identified NF1-related OPG patients in an EHR-derived database. They provided swift insight into the number of NF1-related OPG cases and were able to identify additional cases, which were not included in the original list of known cases. Phenotype algorithms created with OMOP could be an invaluable tool to facilitate patient screening, especially in multi-centric trials for rare diseases.

Neurofibromatosis Type 1 (NF1)-Related Ocular Signs: New Insights on Their Prevalence, Incidence, and Genotype-Phenotype Correlation in NF1 Children

PURPOSE

To assess, in a large pediatric population affected by neurofibromatosis type 1 (NF1), the prevalence, incidence, age of onset, and genotype correlation of the main NF1-related ocular signs, including optic pathway glioma (OPG), Lisch nodules (LNs), choroidal abnormalities (CAs), and retinal vascular abnormalities (RVAs).

METHODS

NF1 patients ≤16 years old followed at our institution between 2010 and 2022 were included. Presence of NF1-related ocular signs was assessed at baseline and during follow-up evaluations through slit lamp observation (LNs), near-infrared imaging (CAs and RVAs), and neuroimaging revision (OPG). Patients were categorized according to their genetic variant.

RESULTS

A total of 237 patients were enrolled. Among those, 204 underwent at least 1 follow-up and genetic test was available for 210. Prevalence of OPG, LNs, CAs, and RVAs at baseline was, respectively, 20.7%, 43.5%, 46.8%, and 6.8%. Their incidence during follow-up was 6.4%, 22.4%, 21.4%, and 5.4%, respectively, and the mean age at onset was 6.3±3.6, 7.1±3.0, 6.4±3.0, and 6.6±2.9 years. Patients with truncating mutations presented a higher number of ocular signs than those with non-truncating mutations (1.7±1.0 vs 0.9±0.9, P = .0019).

CONCLUSIONS

Data on prevalence and incidence of NF1-related ocular signs in pediatric patients evidences that the development of these signs seems negligible after the age of 7. LNs and CAs seem to develop independently and, therefore, can be considered as two separate diagnostic criteria. Truncating mutations correlate with a higher number of NF1-related ocular signs phenotype. Note: Publication of this article is sponsored by the American Ophthalmological Society.

Precocious Puberty in Children with Neurofibromatosis Type 1

This multi-institutional, descriptive study of 19 children with neurofibromatosis 1 examines the link between optic pathway gliomas (OPGs) and central precocious puberty (CPP). We report that CPP can arise without OPG chiasmal involvement and that prior OPG chemotherapy does not prevent the development of CPP.

Human single cell RNA-sequencing reveals a targetable CD8+ exhausted T cell population that maintains mouse low-grade glioma growth

In solid cancers, T cells typically function as cytotoxic effectors to limit tumor growth, prompting therapies that capitalize upon this antineoplastic property (immune checkpoint inhibition; ICI). Unfortunately, ICI treatments have been largely ineffective for high-grade brain tumors (gliomas; HGGs). Leveraging several single-cell RNA sequencing datasets, we report greater CD8+ exhausted T cells in human pediatric low-grade gliomas (LGGs) relative to adult and pediatric HGGs. Using several preclinical mouse LGG models (Nf1-OPG mice), we show that these PD1+/TIGIT+ CD8+ exhausted T cells are restricted to the tumor tissue, where they express paracrine factors necessary for OPG growth. Importantly, ICI treatments with α-PD1 and α-TIGIT antibodies attenuate Nf1-OPG tumor proliferation through suppression of two cytokine (Ccl4 and TGFβ)-mediated mechanisms, rather than by T cell-mediated cytotoxicity, as well as suppress monocyte-controlled T cell chemotaxis. Collectively, these findings establish a previously unrecognized function for CD8+ exhausted T cells as specialized regulators of LGG maintenance.

Update on Pediatric Cancer Surveillance Recommendations for Patients with Neurofibromatosis Type 1, Noonan Syndrome, CBL Syndrome, Costello Syndrome, and Related RASopathies

Neurofibromatosis type 1 (NF1), Noonan syndrome, and related syndromes, grouped as RASopathies, result from dysregulation of the RAS-MAPK pathway and demonstrate varied multisystemic clinical phenotypes. Together, RASopathies are among the more prevalent genetic cancer predisposition syndromes and require nuanced clinical management. When compared with the general population, children with RASopathies are at significantly increased risk of benign and malignant neoplasms. In the past decade, clinical trials have shown that targeted therapies can improve outcomes for low-grade and benign neoplastic lesions but have their own challenges, highlighting the multidisciplinary care needed for such individuals, specifically those with NF1. This perspective, which originated from the 2023 American Association for Cancer Research Childhood Cancer Predisposition Workshop, serves to update pediatric oncologists, neurologists, geneticists, counselors, and other health care professionals on revised diagnostic criteria, review previously published surveillance guidelines, and harmonize updated surveillance recommendations for patients with NF1 or RASopathies.

Low-grade glioma in children with neurofibromatosis type 1: surveillance, treatment indications, management, and future directions

Neurofibromatosis type 1 (NF1) is an autosomal dominant cancer predisposition syndrome characterized by the development of both central and peripheral nervous system tumors. Low-grade glioma (LGG) is the most prevalent central nervous system tumor occurring in children with NF1, arising most frequently within the optic pathway, followed by the brainstem. Historically, treatment of NF1-LGG has been limited to conventional cytotoxic chemotherapy and surgery. Despite treatment with chemotherapy, a subset of children with NF1-LGG fail initial therapy, have a continued decline in function, or recur. The recent development of several preclinical models has allowed for the identification of novel, molecularly targeted therapies. At present, exploration of these novel precision-based therapies is ongoing in the preclinical setting and through larger, collaborative clinical trials. Herein, we review the approach to surveillance and management of NF1-LGG in children and discuss upcoming novel therapies and treatment protocols.

Molecular-targeted therapy for childhood low-grade glial and glioneuronal tumors

Since the discovery of the association between BRAF mutations and fusions in the development of childhood low-grade gliomas and the subsequent recognition that most childhood low-grade glial and glioneuronal tumors have aberrant signaling through the RAS/RAF/MAP kinase pathway, there has been a dramatic change in how these tumors are conceptualized. Many of the fusions and mutations present in these tumors are associated with molecular targets, which have agents in development or already in clinical use. Various agents, including MEK inhibitors, BRAF inhibitors, MTOR inhibitors and, in small subsets of patients NTRK inhibitors, have been used successfully to treat children with recurrent disease, after failure of conventional approaches such as surgery or chemotherapy. The relative benefits of chemotherapy as compared to molecular-targeted therapy for children with newly diagnosed gliomas and neuroglial tumors are under study. Already the combination of an MEK inhibitor and a BRAF inhibitor has been shown superior to conventional chemotherapy (carboplatin and vincristine) in newly diagnosed children with BRAF-V600E mutated low-grade gliomas and neuroglial tumors. However, the long-term effects of such molecular-targeted treatment are unknown. The potential use of molecular-targeted therapy in early treatment has made it mandatory that the molecular make-up of the majority of low-grade glial and glioneuronal tumors is known before initiation of therapy. The primary exception to this rule is in children with neurofibromatosis type 1 who, by definition, have NF1 loss; however, even in this population, gliomas arising in late childhood and adolescence or those not responding to conventional treatment may be candidates for biopsy, especially before entry on molecular-targeted therapy trials.

"Genetic tumor syndromes of the head and neck: Update in the genomic era"

Genetic tumor syndromes are due to inherited genetic mutations, which have recently come to the attention of clinicians due to the widespread adoption of DNA sequencing, ultimately leading to imaging for surveillance. As a result, radiologists must be familiar with the clinical, genetic, and radiologic features of these syndromes. This article reviews genetic tumor syndromes of the head and neck according to the recently updated WHO's 5th edition.

NF1 mutation-driven neuronal hyperexcitability sets a threshold for tumorigenesis and therapeutic targeting of murine optic glioma

BACKGROUND

With the recognition that noncancerous cells function as critical regulators of brain tumor growth, we recently demonstrated that neurons drive low-grade glioma initiation and progression. Using mouse models of neurofibromatosis type 1 (NF1)-associated optic pathway glioma (OPG), we showed that Nf1 mutation induces neuronal hyperexcitability and midkine expression, which activates an immune axis to support tumor growth, such that high-dose lamotrigine treatment reduces Nf1-OPG proliferation. Herein, we execute a series of complementary experiments to address several key knowledge gaps relevant to future clinical translation.

METHODS

We leverage a collection of Nf1-mutant mice that spontaneously develop OPGs to alter both germline and retinal neuron-specific midkine expression. Nf1-mutant mice harboring several different NF1 patient-derived germline mutations were employed to evaluate neuronal excitability and midkine expression. Two distinct Nf1-OPG preclinical mouse models were used to assess lamotrigine effects on tumor progression and growth in vivo.

RESULTS

We establish that neuronal midkine is both necessary and sufficient for Nf1-OPG growth, demonstrating an obligate relationship between germline Nf1 mutation, neuronal excitability, midkine production, and Nf1-OPG proliferation. We show anti-epileptic drug (lamotrigine) specificity in suppressing neuronal midkine production. Relevant to clinical translation, lamotrigine prevents Nf1-OPG progression and suppresses the growth of existing tumors for months following drug cessation. Importantly, lamotrigine abrogates tumor growth in two Nf1-OPG strains using pediatric epilepsy clinical dosing.

CONCLUSIONS

Together, these findings establish midkine and neuronal hyperexcitability as targetable drivers of Nf1-OPG growth and support the use of lamotrigine as a potential chemoprevention or chemotherapy agent for children with NF1-OPG.

Imaging the optic nerve with optical coherence tomography

Optical coherence tomography (OCT) is a non-invasive imaging technology, which may be used to generate in vivo quantitative and qualitative measures of retinal structure. In terms of quantitative metrics, peripapillary retinal nerve fiber layer (pRNFL) thickness provides an indirect evaluation of axonal integrity within the optic nerve. Ganglion layer measures derived from macular scans indirectly reflect retinal ganglion cell status. Notably, ganglion layer indices are platform dependent and may include macular ganglion cell inner plexiform layer (mGCIPL), ganglion cell layer (GCL), and ganglion cell complex (GCC) analyses of thickness or volume. Interpreted together, pRNFL thickness and ganglion layer values can be used to diagnose optic neuropathies, monitor disease progression, and gauge response to therapeutic interventions for neuro-ophthalmic conditions. Qualitative assessments of the optic nerve head, using cross-sectional transverse axial, en face, and circular OCT imaging, may help distinguish papilledema from pseudopapilloedema, and identify outer retinal pathology. Innovations in OCT protocols and approaches including enhanced depth imaging (EDI), swept source (SS) techniques, and angiography (OCTA) may offer future insights regarding the potential pathogenesis of different optic neuropathies. Finally, recent developments in artificial intelligence (AI) utilizing OCT images may overcome longstanding challenges, which have plagued non-vision specialists who often struggle to perform reliable ophthalmoscopy. In this review, we aim to discuss the benefits and pitfalls of OCT, consider the practical applications of this technology in the assessment of optic neuropathies, and highlight scientific discoveries in the realm of optic nerve imaging that will ultimately change how neuro-ophthalmologists care for patients.

An Overview of Optic Pathway Glioma With Neurofibromatosis Type 1: Pathogenesis, Risk Factors, and Therapeutic Strategies

Optic pathway gliomas (OPGs) are most predominant pilocytic astrocytomas, which are typically diagnosed within the first decade of life. The majority of affected children with OPGs also present with neurofibromatosis type 1 (NF1), the most common tumor predisposition syndrome. OPGs in individuals with NF1 primarily affect the optic pathway and lead to visual disturbance. However, it is challenging to assess risk in asymptomatic patients without valid biomarkers. On the other hand, for symptomatic patients, there is still no effective treatment to prevent or recover vision loss. Therefore, this review summarizes current knowledge regarding the pathogenesis of NF1-associated OPGs (NF1-OPGs) from preclinical studies to seek potential prognostic markers and therapeutic targets. First, the loss of the NF1 gene activates 3 distinct Ras effector pathways, including the PI3K/AKT/mTOR pathway, the MEK/ERK pathway, and the cAMP pathway, which mediate glioma tumorigenesis. Meanwhile, non-neoplastic cells from the tumor microenvironment (microglia, T cells, neurons, etc.) also contribute to gliomagenesis via various soluble factors. Subsequently, we investigated potential genetic risk factors, molecularly targeted therapies, and neuroprotective strategies for tumor prevention and vision recovery. Last, potential directions and promising preclinical models of NF1-OPGs are presented for further research. On the whole, NF1-OPGs develop as a result of the interaction between glioma cells and the tumor microenvironment. Developing effective treatments require a better understanding of tumor molecular characteristics, as well as multistage interventions targeting both neoplastic cells and non-neoplastic cells.

Visual Deficits and Diagnostic and Therapeutic Strategies for Neurofibromatosis Type 1: Bridging Science and Patient-Centered Care

Neurofibromatosis type 1 (NF1) is an inherited autosomal dominant disorder primarily affecting children and adolescents characterized by multisystemic clinical manifestations. Mutations in neurofibromin, the protein encoded by the Nf1 tumor suppressor gene, result in dysregulation of the RAS/MAPK pathway leading to uncontrolled cell growth and migration. Neurofibromin is highly expressed in several cell lineages including melanocytes, glial cells, neurons, and Schwann cells. Individuals with NF1 possess a genetic predisposition to central nervous system neoplasms, particularly gliomas affecting the visual pathway, known as optic pathway gliomas (OPGs). While OPGs are typically asymptomatic and benign, they can induce visual impairment in some patients. This review provides insight into the spectrum and visual outcomes of NF1, current diagnostic techniques and therapeutic interventions, and explores the influence of NF1-OPGS on visual abnormalities. We focus on recent advancements in preclinical animal models to elucidate the underlying mechanisms of NF1 pathology and therapies targeting NF1-OPGs. Overall, our review highlights the involvement of retinal ganglion cell dysfunction and degeneration in NF1 disease, and the need for further research to transform scientific laboratory discoveries to improved patient outcomes.

The management of neurofibromatosis type 1 (NF1) in children and adolescents

INTRODUCTION

Neurofibromatosis type 1 (NF1) is a rare neurogenetic disorder characterized by multiple organ system involvement and a predisposition to benign and malignant tumor development. With revised NF1 clinical criteria and the availability of germline genetic testing, there is now an opportunity to render an early diagnosis, expedite medical surveillance, and initiate treatment in a prompt and targeted manner.

AREAS COVERED

The authors review the spectrum of medical problems associated with NF1, focusing specifically on children and young adults. The age-dependent appearance of NF1-associated features is highlighted, and the currently accepted medical treatments are discussed. Additionally, future directions for optimizing the care of this unique population of children are outlined.

EXPERT OPINION

The appearance of NF1-related medical problems is age dependent, requiring surveillance for those features most likely to occur at any given age during childhood. As such, we advocate a life stage-focused screening approach beginning in infancy and continuing through the transition to adult care. With early detection, it becomes possible to promptly institute therapies and reduce patient morbidity. Importantly, with continued advancement in our understanding of disease pathogenesis, future improvements in the care of children with NF1 might incorporate improved risk assessments and more personalized molecularly targeted treatments.

Consensus framework for conducting phase I/II clinical trials for children, adolescents, and young adults with pediatric low-grade glioma: Guidelines established by the International Pediatric Low-Grade Glioma Coalition Clinical Trial Working Group

Within the last few decades, we have witnessed tremendous advancements in the study of pediatric low-grade gliomas (pLGG), leading to a much-improved understanding of their molecular underpinnings. Consequently, we have achieved successful milestones in developing and implementing targeted therapeutic agents for treating these tumors. However, the community continues to face many unknowns when it comes to the most effective clinical implementation of these novel targeted inhibitors or combinations thereof. Questions encompassing optimal dosing strategies, treatment duration, methods for assessing clinical efficacy, and the identification of predictive biomarkers remain unresolved. Here, we offer the consensus of the international pLGG coalition (iPLGGc) clinical trial working group on these important topics and comment on clinical trial design and endpoint rationale. Throughout, we seek to standardize the global approach to early clinical trials (phase I and II) for pLGG, leading to more consistently interpretable results as well as enhancing the pace of novel therapy development and encouraging an increased focus on functional endpoints as well and quality of life for children faced with this disease.

Estrogen-induced glial IL-1β mediates extrinsic retinal ganglion cell vulnerability in murine Nf1 optic glioma

Optic pathway gliomas (OPGs) arising in children with neurofibromatosis type 1 (NF1) can cause retinal ganglion cell (RGC) dysfunction and vision loss, which occurs more frequently in girls. While our previous studies demonstrated that estrogen was partly responsible for this sexually dimorphic visual impairment, herein we elucidate the underlying mechanism. In contrast to their male counterparts, female Nf1OPG mice have increased expression of glial interleukin-1β (IL-1β), which is neurotoxic to RGCs in vitro. Importantly, both IL-1β neutralization and leuprolide-mediated estrogen suppression decrease IL-1β expression and ameliorate RGC dysfunction, providing preclinical proof-of-concept evidence supporting novel neuroprotective strategies for NF1-OPG-induced vision loss.

Pediatric Optic Pathway Gliomas Resource Utilization and Prevalence in the OptumLabs Data Warehouse

BACKGROUND

Although significant progress has been made in improving the rate of survival for pediatric optic pathway gliomas (OPGs), data describing the methods of diagnosis and treatment for OPGs are limited in the modern era. This retrospective study aims to provide an epidemiological overview in the pediatric population and an update on eye care resource utilization in OPG patients using big data analysis.

METHODS

Using the OptumLabs Data Warehouse, 9-11 million children from 2016 to 2021 assessed the presence of an OPG claim. This data set was analyzed for demographic distribution data and clinical data including average ages for computed tomography (CT), MRI, strabismus, and related treatment (surgery, chemotherapy, and radiation), as well as yearly rates for optical coherence tomography (OCT) and visual field (VF) examinations.

RESULTS

Five hundred fifty-one unique patients ranging in age from 0 to 17 years had an OPG claim, with an estimated prevalence of 4.6-6.1 per 100k. Among the 476 OPG patients with at least 6 months of follow-up, 88.9% had at least one MRI and 15.3% had at least one CT. Annual rates for OCT and VF testing were similar (1.26 vs 1.35 per year), although OCT was ordered for younger patients (mean age = 9.2 vs 11.7 years, respectively). During the study period, 14.1% of OPG patients had chemotherapy, 6.1% had either surgery or radiation, and 81.7% had no treatment.

CONCLUSIONS

This study updates OPG demographics for the modern era and characterizes the burden of the treatment course for pediatric OPG patients using big data analysis of a commercial claims database. OPGs had a prevalence of about 0.005% occurring equally in boys and girls. Most did not receive treatment, and the average child had at least one claim for OCT or VF per year for clinical monitoring. This study is limited to only commercially insured children, who represent approximately half of the general child population.

Optic Pathway Gliomas in Pediatric Population-Current Approach in Diagnosis and Management: Literature Review

In this paper, the authors present a clinical picture of the diagnosis and current treatment regimens of optic pathway glioma in the pediatric population, with an emphasis on the role of an ophthalmic diagnosis in the differentiation and monitoring of lesions. Glioma is the most common optic nerve tumor in children.

MATERIAL

Articles in PubMed, Scholar and Website were reviewed, taking into account current standards of management related to sporadic or NF1-related optic glioma, epidemiology, location, course of the disease, clinical manifestations, histological types of the tumor, genetic predisposition, diagnostic ophthalmic tests currently applicable in therapeutic monitoring of the tumor, neurological diagnosis, therapeutic management and prognosis. The importance of current screening recommendations, in line with standards, was emphasized.

RESULTS

Glioma occurs in children most often in the first decade of life. Initially, they may be asymptomatic, and clinically ophthalmic changes are associated with the organ of vision or with systemic changes. Gliomas associated with the NF1 mutation have a better prognosis for sporadic gliomas. Diagnosis includes radiological imaging methods/MRI/ophthalmology/OCT and visual acuity log MAR assessment. The basis of treatment is clinical observation. In the case of disease progression, surgical treatment, chemotherapy and targeted therapy are used.

CONCLUSION

Further research into novel techniques for detecting gliomas would allow for early monitoring of the disease.

Neuroendoscopy: intraventricular and skull base tumor resection in children

During the last 30 years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

Retinal ganglion cell repopulation for vision restoration in optic neuropathy: a roadmap from the RReSTORe Consortium

Retinal ganglion cell (RGC) death in glaucoma and other optic neuropathies results in irreversible vision loss due to the mammalian central nervous system's limited regenerative capacity. RGC repopulation is a promising therapeutic approach to reverse vision loss from optic neuropathies if the newly introduced neurons can reestablish functional retinal and thalamic circuits. In theory, RGCs might be repopulated through the transplantation of stem cell-derived neurons or via the induction of endogenous transdifferentiation. The RGC Repopulation, Stem Cell Transplantation, and Optic Nerve Regeneration (RReSTORe) Consortium was established to address the challenges associated with the therapeutic repair of the visual pathway in optic neuropathy. In 2022, the RReSTORe Consortium initiated ongoing international collaborative discussions to advance the RGC repopulation field and has identified five critical areas of focus: (1) RGC development and differentiation, (2) Transplantation methods and models, (3) RGC survival, maturation, and host interactions, (4) Inner retinal wiring, and (5) Eye-to-brain connectivity. Here, we discuss the most pertinent questions and challenges that exist on the path to clinical translation and suggest experimental directions to propel this work going forward. Using these five subtopic discussion groups (SDGs) as a framework, we suggest multidisciplinary approaches to restore the diseased visual pathway by leveraging groundbreaking insights from developmental neuroscience, stem cell biology, molecular biology, optical imaging, animal models of optic neuropathy, immunology & immunotolerance, neuropathology & neuroprotection, materials science & biomedical engineering, and regenerative neuroscience. While significant hurdles remain, the RReSTORe Consortium's efforts provide a comprehensive roadmap for advancing the RGC repopulation field and hold potential for transformative progress in restoring vision in patients suffering from optic neuropathies.

The impact of changes in gadolinium-enhancement on disease progression in children with neurofibromatosis type 1-associated optic pathway glioma: a retrospective analysis

PURPOSE

There has been limited investigation of imaging features associated with visual acuity (VA) decline and initiation of treatment for patients with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG).

METHODS

To evaluate the association of increased gadolinium enhancement with decline in VA, initiation of chemotherapy, and tumor growth, we performed a retrospective cohort study of children diagnosed with NF1-OPG between January 2006 to June 2016. Two cohorts were defined: a new diagnosis and a longitudinal cohort. Outcomes were examined at 1 and 2 years from initial diagnosis, and 1 and 2 years from initial increase in enhancement in the longitudinal cohort.

RESULTS

Eighty patients were eligible; all 80 contributed to the new diagnosis cohort and 73 to the longitudinal cohort. Fifty-six patients (70%) demonstrated enhancing NF1-OPG at diagnosis. 39% of patients in the new diagnosis cohort and 45% of those in the longitudinal cohort developed increased enhancement during the study period. There was no significant association between increases in enhancement and VA decline in the newly diagnosed or longitudinal cohorts, as well as with initiation of treatment in the longitudinal cohort. Although there was an association of enhancement increase with treatment in the new diagnosis cohort, this association was not maintained when stratified by concurrent change in tumor size.

CONCLUSION

Increased gadolinium-enhancement independent of a concurrent increase in tumor size on MRI should not be used as a marker of NF1-OPG progression and does not appear to be associated with visual decline or initiation of chemotherapy.

Clinical, histological, and molecular features of gliomas in adults with neurofibromatosis type 1

BACKGROUND

People with NF1 have an increased prevalence of central nervous system malignancy. However, little is known about the clinical course or pathologic features of NF1-associated gliomas in adults, limiting clinical care and research.

METHODS

Adults (≥18 years) with NF1 and histologically confirmed non-optic pathway gliomas (non-OPGs) at Johns Hopkins Hospital, Memorial Sloan Kettering Cancer Center, and Washington University presenting between 1990 and 2020 were identified. Retrospective data were collated, and pathology was reviewed centrally.

RESULTS

Forty-five patients, comprising 23 females (51%), met eligibility criteria, with a median of age 37 (18-68 years) and performance status of 80% (30%-100%). Tissue was available for 35 patients. Diagnoses included infiltrating (low-grade) astrocytoma (9), glioblastoma (7), high-grade astrocytoma with piloid features (4), pilocytic astrocytoma (4), high-grade astrocytoma (3), WHO diagnosis not reached (4) and one each of gliosarcoma, ganglioglioma, embryonal tumor, and diffuse midline glioma. Seventy-one percent of tumors were midline and underwent biopsy only. All 27 tumors evaluated were IDH1-wild-type, independent of histology. In the 10 cases with molecular testing, the most common genetic variants were NF1, EGFR, ATRX, CDKN2A/B, TP53, TERT, and MSH2/3 mutation. While the treatments provided varied, the median overall survival was 24 months [2-267 months] across all ages, and 38.5 [18-109] months in individuals with grade 1-2 gliomas.

CONCLUSIONS

Non-OPGs in adults with NF1, including low-grade tumors, often have an aggressive clinical course, indicating a need to better understand the pathobiology of these NF1-associated gliomas.

Neurofibromatosis Type 1-Associated Optic Pathway Gliomas: Current Challenges and Future Prospects

Optic pathway glioma (OPG) occurs in as many as one-fifth of individuals with the neurofibromatosis type 1 (NF1) cancer predisposition syndrome. Generally considered low-grade and slow growing, many children with NF1-OPGs remain asymptomatic. However, due to their location within the optic pathway, ~20-30% of those harboring NF1-OPGs will experience symptoms, including progressive vision loss, proptosis, diplopia, and precocious puberty. While treatment with conventional chemotherapy is largely effective at attenuating tumor growth, it is not clear whether there is much long-term recovery of visual function. Additionally, because these tumors predominantly affect young children, there are unique challenges to NF1-OPG diagnosis, monitoring, and longitudinal management. Over the past two decades, the employment of authenticated genetically engineered Nf1-OPG mouse models have provided key insights into the function of the NF1 protein, neurofibromin, as well as the molecular and cellular pathways that contribute to optic gliomagenesis. Findings from these studies have resulted in the identification of new molecular targets whose inhibition blocks murine Nf1-OPG growth in preclinical studies. Some of these promising compounds have now entered into early clinical trials. Future research focused on defining the determinants that underlie optic glioma initiation, expansion, and tumor-induced optic nerve injury will pave the way to personalized risk assessment strategies, improved tumor monitoring, and optimized treatment plans for children with NF1-OPG.

Automatic Visual Acuity Loss Prediction in Children with Optic Pathway Gliomas using Magnetic Resonance Imaging

Children with optic pathway gliomas (OPGs), a low-grade brain tumor associated with neurofibromatosis type 1 (NF1-OPG), are at risk for permanent vision loss. While OPG size has been associated with vision loss, it is unclear how changes in size, shape, and imaging features of OPGs are associated with the likelihood of vision loss. This paper presents a fully automatic framework for accurate prediction of visual acuity loss using multi-sequence magnetic resonance images (MRIs). Our proposed framework includes a transformer-based segmentation network using transfer learning, statistical analysis of radiomic features, and a machine learning method for predicting vision loss. Our segmentation network was evaluated on multi-sequence MRIs acquired from 75 pediatric subjects with NF1-OPG and obtained an average Dice similarity coefficient of 0.791. The ability to predict vision loss was evaluated on a subset of 25 subjects with ground truth using cross-validation and achieved an average accuracy of 0.8. Analyzing multiple MRI features appear to be good indicators of vision loss, potentially permitting early treatment decisions.Clinical relevance- Accurately determining which children with NF1-OPGs are at risk and hence require preventive treatment before vision loss remains challenging, towards this we present a fully automatic deep learning-based framework for vision outcome prediction, potentially permitting early treatment decisions.

An unusual presentation of bilateral optic pathway glioma in Crouzon Syndrome

Crouzon Syndrome is a genetic craniosynostosis disorder associated with a high risk of ophthalmologic sequelae secondary to structural causes. However, ophthalmologic disorders due to intrinsic nerve aberrations in Crouzon Syndrome have not been described. Optic pathway gliomas (OPGs) are low grade gliomas that are intrinsic to the visual pathway, frequently associated with Neurofibromatosis type 1 (NF-1). OPGs involving both optic nerves without affecting the optic chiasm are rarely seen outside of NF-1. We report an unusual case of bilateral optic nerve glioma without chiasmatic involvement in a 17-month-old male patient with Crouzon Syndrome without any clinical or genetic findings of NF-1. This case suggests that close ophthalmologic follow up and orbital MRIs may benefit patients with Crouzon Syndrome.

The role of visual electrodiagnostics in management of children with neurofibromatosis type 1

PURPOSE

To evaluate the role of visual electrodiagnostic testing in children with neurofibromatosis type 1 (NF1) despite improved accessibility to magnetic resonance imaging (MRI).

METHODS

The records from 39 children (78 eyes, 15 boys, 24 girls, average age at last visit of 11.5 ± 4.3 years, average follow-up time of 7.8 ± 3.9 years) with genetically confirmed NF1 were retrospectively analysed. They all underwent a thorough ophthalmological investigation, including age-appropriate visual acuity testing, anterior segment evaluation for Lisch nodules and a dilated fundus examination. If children were cooperative enough, colour vision was tested using the Hardy-Rand-Rittler test, visual fields were evaluated with Goldmann perimetry. All performed MRI of the brain and orbits as part of the standard of care protocol. Visual electrodiagnostics included electroretinography (ERG) and visual evoked potentials (VEP) using a standard protocol in older children, whereas with less cooperative children a modified protocol according to the Great Ormond Street Hospital (GOSH protocol) was used.

RESULTS

The average visual acuity was 0.8 ± 0.3, colour vision was abnormal in 6%, perimetry in 8%, Lisch nodules were present in 62%, and the optic disc was pale in 66% of all eyes. Plexiform neurofibroma of the eyelid/orbit was present in 4%. Optic pathway glioma (OPG) was detected with MRI in 22 (57%) and in 6/22 treatment was indicated. Other intracranial NF1-related lesions were documented in 70% of children. VEP were abnormal in 16/39 of all children with NF1 (41%) comprising 14/22 (65%) of children with confirmed OPG and 2/17 (12%) of children without OPG. All full-field and pattern ERG responses were within normal limits. All individual VEP results are described and three cases from this cohort of children are presented in detail to illustrate the importance of VEP testing. In Case 1, VEP abnormality suggested subsequent MRI of the brain under general anaesthesia, which was otherwise contraindicated according to normal clinical findings and his young age. In Cases 2 and 3, VEP provided more precise functional information during the follow-up of OPG, while other psychophysical tests remained unchanged.

CONCLUSIONS

Electrodiagnostics has multifactorial role and importance in children with NF1, either when visual pathway function is impaired in young children, even before MRI under general anaesthesia and other psychophysical tests can be performed, as well as for a more precise monitoring of the visual pathway function before potential treatment of OPG, or after it, to evaluate its success.

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.

[Neurofibromatosis type 1 : From diagnosis to follow-up]

BACKGROUND

Neurofibromatosis type 1 (NF1) is a tumor predisposition syndrome and is one of the most common genetic diseases. It is therefore a condition encountered by radiologists in clinical routine. Since the variability of the clinical expression is very high and several organ systems are affected, we present a standardized diagnostic approach in this article.

METHODS

Evaluation of the literature on neurofibromatosis type 1 in the context of radiological examination methods.

RESULTS

In addition to the frequently known changes in the central and peripheral nervous system such as optic gliomas and plexiform neurofibromas, lesions from the orthopedic spectrum and vascular changes must also be included in the radiological diagnosis.

CONCLUSIONS

Due to the diversity of the clinical picture of NF1, it is reasonable to define an examination strategy which takes into account the needs of radiological routine and also reliably detects the most frequent and prognostically significant pathologies accompanying this disease. In this article, the current recommendations for diagnosis of neurofibromatosis-associated tumors and skeletal changes are summarized, and examination protocols and time intervals are suggested.

Atypical and typical course of neurofibromatosis type 1 in combination with pheochromocytoma

Neurofibromatosis type 1 is a hereditary disease that has a multisystem character of organism damage, a wide variability of clinical manifestations, up to the almost complete absence of typical symptoms. Phenotypic manifestations, their expressiveness and heaviness can be varied even among members of the same family with identical mutations. One of the possible clinical manifestations of this pathology is pheochromocytoma, the development of which is associated with a high risk of developing life-threatening conditions. Timely diagnosis of the disease, the choice of treatment tactics for the patient, genetic testing of blood relatives can significantly improve the survival rate and prognosis of the disease. In this article, on the presented clinical examples of patients with a typical and atypical course of type 1 neurofibromatosis in combination with pheochromocytoma, the issues of managing patients with this pathology are outlined.

Nervous system (NS) Tumors in Cancer Predisposition Syndromes

Genetic syndromes which develop one or more nervous system (NS) tumors as one of the manifestations can be grouped under the umbrella term of NS tumor predisposition syndromes. Understanding the underlying pathological pathways at the molecular level has led us to many radical discoveries, in understanding the mechanisms of tumorigenesis, tumor progression, interactions with the tumor microenvironment, and development of targeted therapies. Currently, at least 7-10% of all pediatric cancers are now recognized to occur in the setting of genetic predisposition to cancer or cancer predisposition syndromes. Specifically, the cancer predisposition rate in pediatric patients with NS tumors has been reported to be as high as 15%, though it can approach 50% in certain tumor types (i.e., choroid plexus carcinoma associated with Li Fraumeni Syndrome). Cancer predisposition syndromes are caused by pathogenic variation in genes that primarily function as tumor suppressors and proto-oncogenes. These variants are found in the germline or constitutional DNA. Mosaicism, however, can affect only certain tissues, resulting in varied manifestations. Increased understanding of the genetic underpinnings of cancer predisposition syndromes and the ability of clinical laboratories to offer molecular genetic testing allows for improvement in the identification of these patients. The identification of a cancer predisposition syndrome in a CNS tumor patient allows for changes to medical management to be made, including the initiation of cancer surveillance protocols. Finally, the identification of at-risk biologic relatives becomes feasible through cascade (genetic) testing. These fundamental discoveries have also broadened the horizon of novel therapeutic possibilities and have helped to be better predictors of prognosis and survival. The treatment paradigm of specific NS tumors may also vary based on the patient's cancer predisposition syndrome and may be used to guide therapy (i.e., immune checkpoint inhibitors in constitutional mismatch repair deficiency [CMMRD] predisposition syndrome) [8]. Early diagnosis of these cancer predisposition syndromes is therefore critical, in both unaffected and affected patients. Genetic counselors are uniquely trained master's level healthcare providers with a focus on the identification of hereditary disorders, including hereditary cancer, or cancer predisposition syndromes. Genetic counseling, defined as "the process of helping people understand and adapt to the medical, psychological and familial implications of genetic contributions to disease" plays a vital role in the adaptation to a genetic diagnosis and the overall management of these diseases. Cancer predisposition syndromes that increase risks for NS tumor development in childhood include classic neurocutaneous disorders like neurofibromatosis type 1 and type 2 (NF1, NF2) and tuberous sclerosis complex (TSC) type 1 and 2 (TSC1, TSC2). Li Fraumeni Syndrome, Constitutional Mismatch Repair Deficiency, Gorlin syndrome (Nevoid Basal Cell Carcinoma), Rhabdoid Tumor Predisposition syndrome, and Von Hippel-Lindau disease. Ataxia Telangiectasia will also be discussed given the profound neurological manifestations of this syndrome. In addition, there are other cancer predisposition syndromes like Cowden/PTEN Hamartoma Tumor Syndrome, DICER1 syndrome, among many others which also increase the risk of NS neoplasia and are briefly described. Herein, we discuss the NS tumor spectrum seen in the abovementioned cancer predisposition syndromes as with their respective germline genetic abnormalities and recommended surveillance guidelines when applicable. We conclude with a discussion of the importance and rationale for genetic counseling in these patients and their families.

Optic Pathway Glioma in Children with Neurofibromatosis Type 1: A Multidisciplinary Entity, Posing Dilemmas in Diagnosis and Management Multidisciplinary Management of Optic Pathway Glioma in Children with Neurofibromatosis Type 1

Introduction

Neurofibromatosis type 1 (NF1) has an incidence of 1 in 2,000 to 3,000 individuals and in 15% is associated with optic pathway glioma (OPG). Given the variability in clinical presentation and related morbidity, a multidisciplinary approach for diagnosis and management of children with NF1 and OPG is required, but often lacks coordination and regular information exchange. Herein we summarize our experience and describe the care pathways/network provided by a multidisciplinary team. The role of the distinct team members is elucidated as well as the care amendments made over time.

Methods

We performed a retrospective single-center observational study, including children treated at our institution between 1990 and 2021. Inclusion criteria were clinical diagnosis of NF1, radiographic and/or histopathological diagnosis of OPG and age below 18 years. Patients being treated elsewhere were excluded from the study. Data was abstracted from each child’s health record using a standardized data collection form. Characteristics of children with NF1 and OPG were described using means (SD) and percentages. Outcomes were determined using Kaplan-Meier estimates.

Results

From 1990 to 2021, 1,337 children were followed in our institution. Of those, 195 were diagnosed with OPG (14.6%), including 94 (48.21%) females and 101 (51.79%) males. Comprehensive data were available in 150 patients. The mean (SD) age at diagnosis was 5.31(4.08) years (range: 0.8–17.04 years). Sixty-two (41.3%) patients remained stable and did not undergo treatment, whereas 88 (58.7%) patients required at least one treatment. The mean (SD) duration of follow up was 8.14 (5.46) years (range: 0.1–25.9 years; median 6.8 years). Overall survival was of 23.6 years (±1.08), comprising 5 deaths. A dedicated NF clinic, including pediatricians and a nurse, provides regular follow up and plays a central role in the management of children with NF1, identifying those at risk of OPG, coordinating referrals to Neuroradiology and other specialists as indicated. All children are assessed annually by Ophthalmology. Comprehensive care was provided by a multidisciplinary team consisting of Dermatology, Genetics, Neuro-oncology, Neuroradiology, Neurosurgery, Ophthalmology and Pediatrics.

Conclusions

The care of children with NF1 and OPG is optimized with a multidisciplinary team approach, coordinated by a central specialty clinic.

Multidisciplinary neurocutaneous syndrome clinics: a systematic review and institutional experience

OBJECTIVE

Neurocutaneous syndromes have variable multisystem involvement. The multiorgan involvement, potential pathologies, and various treatment options necessitate collaboration and open discussion to ensure optimal treatment in any given patient. These disorders provide quintessential examples of chronic medical conditions that require a lifelong, multidisciplinary approach. The objectives of this study were to 1) perform a systematic review, thoroughly assessing different multidisciplinary clinic layouts utilized in centers worldwide; and 2) characterize an institutional experience with the management of these conditions, focusing on the patient demographics, clinical presentation, complications, and therapeutic strategies seen in a patient population.

METHODS

A systematic review of studies involving multidisciplinary clinics and their reported structure was performed according to PRISMA guidelines using the PubMed database. Then a retrospective chart review of patients enrolled in the Oklahoma Children’s Hospital Neurocutaneous Syndromes Clinic was conducted.

RESULTS

A search of the PubMed database yielded 251 unique results. Of these, 15 papers were included in the analysis, which identified 16 clinics that treated more than 2000 patients worldwide. The majority of these clinics treated patients with neurofibromatosis (13/16). The remaining clinics treated patients with von Hippel–Lindau syndrome (n = 1), tuberous sclerosis complex (n = 1), and multiple neurocutaneous syndromes (n = 1). The most commonly represented subspecialties in these clinics were genetics (15/16) and neurology (13/16). Five clinics (31%) solely saw pediatric patients, 10 clinics saw a combination of children and adults, and the final clinic had separate pediatric and adult clinics. The retrospective chart review of the Neurocutaneous Syndromes Clinic demonstrated that 164 patients were enrolled and seen in the clinic from April 2013 to December 2021. Diagnoses were made based on clinical findings or results of genetic testing; 115 (70%) had neurofibromatosis type 1, 9 (5.5%) had neurofibromatosis type 2, 35 (21%) had tuberous sclerosis complex, 2 (1%) had von Hippel–Lindau syndrome, 2 (1%) had Gorlin syndrome, and the remaining patient (0.6%) had Aarskog-Scott syndrome. Patient demographics, clinical presentation, complications, and therapeutic strategies are also discussed.

CONCLUSIONS

To the best of the authors’ knowledge, this is the first detailed description of a comprehensive pediatric neurocutaneous clinic in the US that serves patients with multiple syndromes. There is currently heterogeneity between described multidisciplinary clinic structures and practices. More detailed accounts of clinic compositions and practices along with patient data and outcomes are needed in order to establish the most comprehensive and efficient multidisciplinary approach for neurocutaneous syndromes.

Imaging Findings of Pediatric Orbital Masses and Tumor Mimics

Pediatric orbital masses are not common but encompass a wide spectrum of benign and malignant entities that range from developmental anomalies to primary and secondary orbital malignancies and metastatic disease. Certain orbital tumors are unique to pediatric patients, such as retinoblastoma and neuroblastoma. Clinical symptoms and signs are often insufficient to differentiate between orbital lesions, and imaging is essential for narrowing the diagnostic considerations and determining the most appropriate management strategy. MRI is the primary imaging modality for evaluating orbital masses in children, with US and CT playing complementary roles. The authors review a spectrum of masses and tumor mimics that affect the pediatric globe and orbit. The shared and differentiating characteristics of pediatric orbital lesions are reviewed. Emphasis is placed on utilizing an orbital compartment-based approach to narrow the differential diagnosis. By using this organizational scheme, the authors describe intraocular processes (retinoblastoma, persistent fetal vasculature, and Coats disease), intraconal lesions (lymphatic malformation, schwannoma, optic nerve sheath meningioma, and optic pathway glioma), extraconal lesions (infantile hemangioma, rhabdomyosarcoma, idiopathic orbital inflammation, lymphoma, venous varix, plexiform neurofibroma, and pleomorphic adenoma of the lacrimal gland), and lesions involving the bony orbit (dermoid cyst, metastatic neuroblastoma, and Langerhans cell histiocytosis). The authors describe the basic management of each entity. Orbital infections and traumatic lesions are beyond the scope of this article. ^©RSNA, 2022.

The role of frailty in the clinical management of neurofibromatosis type 1: a mixed-effects modeling study using the Nationwide Readmissions Database

OBJECTIVE

Frailty embodies a state of increased medical vulnerability that is most often secondary to age-associated decline. Recent literature has highlighted the role of frailty and its association with significantly higher rates of morbidity and mortality in patients with CNS neoplasms. There is a paucity of research regarding the effects of frailty as it relates to neurocutaneous disorders, namely, neurofibromatosis type 1 (NF1). In this study, the authors evaluated the role of frailty in patients with NF1 and compared its predictive usefulness against the Elixhauser Comorbidity Index (ECI).

METHODS

Publicly available 2016–2017 data from the Nationwide Readmissions Database was used to identify patients with a diagnosis of NF1 who underwent neurosurgical resection of an intracranial tumor. Patient frailty was queried using the Johns Hopkins Adjusted Clinical Groups frailty-defining indicator. ECI scores were collected in patients for quantitative measurement of comorbidities. Propensity score matching was performed for age, sex, ECI, insurance type, and median income by zip code, which yielded 60 frail and 60 nonfrail patients. Receiver operating characteristic (ROC) curves were created for complications, including mortality, nonroutine discharge, financial costs, length of stay (LOS), and readmissions while using comorbidity indices as predictor values. The area under the curve (AUC) of each ROC served as a proxy for model performance.

RESULTS

After propensity matching of the groups, frail patients had an increased mean ± SD hospital cost ($85,441.67 ± $59,201.09) compared with nonfrail patients ($49,321.77 ± $50,705.80) (p = 0.010). Similar trends were also found in LOS between frail (23.1 ± 14.2 days) and nonfrail (10.7 ± 10.5 days) patients (p = 0.0020). For each complication of interest, ROC curves revealed that frailty scores, ECI scores, and a combination of frailty+ECI were similarly accurate predictors of variables (p > 0.05). Frailty+ECI (AUC 0.929) outperformed using only ECI for the variable of increased LOS (AUC 0.833) (p = 0.013). When considering 1-year readmission, frailty (AUC 0.642) was outperformed by both models using ECI (AUC 0.725, p = 0.039) and frailty+ECI (AUC 0.734, p = 0.038).

CONCLUSIONS

These findings suggest that frailty and ECI are useful in predicting key complications, including mortality, nonroutine discharge, readmission, LOS, and higher costs in NF1 patients undergoing intracranial tumor resection. Consideration of a patient’s frailty status is pertinent to guide appropriate inpatient management as well as resource allocation and discharge planning.

Comparison of Visual Acuity Results Between ATS-HOTV and E-ETDRS Testing Methods in Children With Optic Pathway Gliomas

Purpose

To determine if visual acuity (VA) outcomes are comparable using the amblyopia treatment study HOTV protocol (ATS-HOTV) and electronic Early Treatment of Diabetic Retinopathy Study (E-ETDRS) protocol in children with optic pathway gliomas (OPGs).

Methods

Children enrolled in a prospective study of OPGs were eligible if they completed both the ATS-HOTV and E-ETDRS during the same visit. The contribution of age, testing order, having neurofibromatosis type 1, visual field loss, and circumpapillary retinal nerve fiber layer thickness to VA difference were assessed using generalized estimating equations to account for the intereye correlation.

Results

Forty-eight children (median age, 10.3 years; range, 5.2-17.1 years; 49% female) met inclusion criteria and contributed 93 study eyes at their initial visit. Eleven patients (22 eyes) had more than one study visit, permitting longitudinal evaluation. ATS-HOTV measures of VA were higher than E-ETDRS at the initial (0.13 ± 0.36 vs. 0.23 ± 0.39 logarithm of the minimum angle of resolution [logMAR], P < 0.001) and all visits (0.13 ± 0.34 vs. 0.21 ± 0.36 logMAR, P < 0.001). VA remained significantly higher with ATS-HOTV regardless of test order, but the mean difference between tests was most profound when tested with ATS-HOTV first compared to E-ETDRS first (P < 0.001).

Conclusions

VA results differ significantly between the ATS-HOTV and E-ETDRS testing methods in children with OPGs. Given the wide range of ages and testing ability of children, one VA testing method should be used throughout longitudinal OPG clinical trials.

Translational Relevance

It is imperative that age-appropriate VA testing methods are standardized across all pediatric OPG clinical trials.

Visual Outcomes of Optic Pathway Glioma Treated With Chemotherapy in Neurofibromatosis Type 1

PURPOSE

To analyze the visual outcomes following chemotherapy for optic pathway glioma in children with neurofibromatosis type 1.

METHODS

This was a retrospective cohort study of 58 children with optic pathway glioma between 2003 and 2019. Best corrected visual acuity (BCVA) at diagnosis and at the last follow-up visit were analyzed. Correlation tests were performed to determine whether the final BCVA was predicted by the initial BCVA, initial Dodge stage, or retinal nerve fiber layer (RNFL) thickness stability. The first-line chemotherapy regimen included vincristine plus carboplatin (2003 to 2016) and vinblastine (since 2017).

RESULTS

Twenty-four children (41%) received chemotherapy. The median age at diagnosis was 3 years, and 61% of the children were female. From the first visit to the last follow-up visit, there was a statistically significant difference in mean BCVA in eyes in the no treatment group (P = .034) but not in eyes in the chemotherapy group (P = .824). A moderate and weak positive correlation was found (r = 0.58 and r = 0.29, respectively). At the last follow-up visit, BCVA remained stable in 73% and improved in 27% of eyes in the no treatment group, and BCVA worsened in 25%, remained stable in 62%, and improved in 13% of eyes in the chemotherapy group. At the last follow-up visit, BCVA and Dodge stage had a weak negative correlation (r = -0.06 and r = -0.17, respectively). A negative moderate correlation was identified between RNFL thickness and BCVA at the last follow-up visit (r = -0.48 in the no treatment group and r = -0.46 in the chemotherapy group).

CONCLUSIONS

Children treated with chemotherapy had worse BCVA, although the treatment arrested the decline or improved BCVA in 75% of the patients with no major side effects. [J Pediatr Ophthalmol Strabismus. 2022;59(2):128-135.].

A 40-Year Cohort Study of Evolving Hypothalamic Dysfunction in Infants and Young Children (<3 years) with Optic Pathway Gliomas

Simple Summary

Serious, poorly understood health issues affect young children with optic pathway tumours. We studied the risk of developing life-limiting hormonal, metabolic, and neurobehavioural disorders by tumour position, recurrence, and treatment, in those diagnosed under 3 years. We found the highest risk for future complex health issues in those presenting with failure to thrive, under one year of age, and/or a tumour involving a deep midbrain area called the hypothalamus. Time, repeated tumour growth, and salvage therapies (radiotherapy, surgery) contributed. We highlight the need for a better understanding of tumour-induced midbrain injury and for neurobehavioural and hormonal support to inform rehabilitation in the growing years, during and beyond cure, to optimise quality of life for these survivors and their families. This might inform oncology treatment strategies and determine new areas for support and collaborative neuroscience research in this high survival group.

Abstract

Despite high survival, paediatric optic pathway hypothalamic gliomas are associated with significant morbidity and late mortality. Those youngest at presentation have the worst outcomes. We aimed to assess presenting disease, tumour location, and treatment factors implicated in the evolution of neuroendocrine, metabolic, and neurobehavioural morbidity in 90 infants/children diagnosed before their third birthday and followed-up for 9.5 years (range 0.5–25.0). A total of 52 (57.8%) patients experienced endo-metabolic dysfunction (EMD), the large majority (46) of whom had hypothalamic involvement (H+) and lower endocrine event-free survival (EEFS) rates. EMD was greatly increased by a diencephalic syndrome presentation (85.2% vs. 46%, p = 0.001)), H+ (OR 6.1 95% CI 1.7–21.7, p 0.005), radiotherapy (OR 16.2, 95% CI 1.7–158.6, p = 0.017) and surgery (OR 4.8 95% CI 1.3–17.2, p = 0.015), all associated with anterior pituitary disorders. Obesity occurred in 25% of cases and was clustered with the endocrinopathies. Neurobehavioural deficits occurred in over half (52) of the cohort and were associated with H+ (OR 2.5 95% C.I. 1.1–5.9, p = 0.043) and radiotherapy (OR 23.1 C.I. 2.9–182, p = 0.003). Very young children with OPHG carry a high risk of endo-metabolic and neurobehavioural comorbidities which deserve better understanding and timely/parallel support from diagnosis to improve outcomes. These evolve in complex, hierarchical patterns over time whose aetiology appears predominantly determined by injury from the hypothalamic tumour location alongside adjuvant treatment strategies.

Risk factors for treatment-refractory and relapsed optic pathway glioma in children with neurofibromatosis type 1

BACKGROUND

Nearly one-third of patients with neurofibromatosis type 1-associated optic pathway glioma (NF1-OPG) fail frontline chemotherapy; however, little is known about risk factors for treatment failure.

METHODS

We performed a retrospective multi-institutional cohort study to identify baseline risk factors for treatment-refractory/relapsed disease and poor visual outcome in children with NF1-OPG. Refractory/relapsed NF1-OPG was defined as a requirement of two or more treatment regimens due to progression or relapse.

RESULTS

Of 111 subjects eligible for inclusion, adequate clinical and visual data were available for 103 subjects from 7 institutions. Median follow-up from the initiation of first chemotherapy regimen was 95 months (range 13-185). Eighty-four (82%) subjects received carboplatin-based frontline chemotherapy. Forty-five subjects (44%) experienced refractory/relapsed disease, with a median time of 21.5 months (range 2-149) from the initiation of first treatment to the start of second treatment. The proportion of patients without refractory/relapsed disease at 2 and 5 years was 78% and 60%. In multivariable analyses, age less than 24 months at initial treatment, posterior tumor location, and familial inheritance were associated with refractory/relapsed NF1-OPG by 2 years. Both age less than 24 months and posterior tumor location were associated with refractory/relapsed NF1-OPG by 5 years. Subjects with moderate to severe vision loss at last follow-up were more likely to have posterior tumor location, optic disc abnormalities, or abnormal visual acuity at initial treatment.

CONCLUSION

Young age, posterior tumor location, and optic disc abnormalities may identify patients with the greatest likelihood of refractory/relapsed NF1-OPG and poor visual outcomes, and who may benefit from newer treatment strategies.

Immune deconvolution and temporal mapping identifies stromal targets and developmental intervals for abrogating murine low-grade optic glioma formation

BACKGROUND

Brain tumor formation and progression are dictated by cooperative interactions between neoplastic and non-neoplastic cells. This stromal dependence is nicely illustrated by tumors arising in the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome, where children develop low-grade optic pathway gliomas (OPGs). Using several authenticated Nf1-OPG murine models, we previously demonstrated that murine Nf1-OPG growth is regulated by T cell function and microglia Ccl5 production, such that their inhibition reduces tumor proliferation in vivo. While these interactions are critical for established Nf1-OPG tumor growth, their importance in tumor formation has not been explored.

METHODS

A combination of bulk and single-cell RNA mouse optic nerve sequencing, immunohistochemistry, T cell assays, and pharmacologic and antibody-mediated inhibition methods were used in these experiments.

RESULTS

We show that T cells and microglia are the main non-neoplastic immune cell populations in both murine and human LGGs. Moreover, we demonstrate that CD8+ T cells, the predominant LGG-infiltrating lymphocyte population, are selectively recruited through increased Ccl2 receptor (Ccr4) expression in CD8+, but not CD4+, T cells, in a NF1/RAS-dependent manner. Finally, we identify the times during gliomagenesis when microglia Ccl5 production (3-6 weeks of age) and Ccl2-mediated T cell infiltration (7-10 weeks of age) occur, such that temporally-restricted Ccl2 or Ccl5 inhibition abrogates tumor formation >3.5 months following the cessation of treatment.

CONCLUSIONS

Collectively, these findings provide proof-of-concept demonstrations that targeting stromal support during early gliomagenesis durably blocks murine LGG formation.

Optic pathway glioma and the sex association in neurofibromatosis type 1: a single-center study

Background

Low-grade optic pathway glioma (OPG) develops in 15–20% of children with neurofibromatosis type 1 (NF1). OPGs are symptomatic in 30–50% and one-third of these require treatment. A few studies have suggested female sex as a risk factor for visual impairment associated with NF1-OPG. This descriptive study investigated the correlation between NF1-OPG growth, sex and visual impairment.

Method

We based our cross-sectional study on a systematic, retrospective data collection in a NF1 cohort of children and adolescents below 21 years of age followed at Center for Rare Diseases, Aarhus University Hospital, Denmark. For each patient with OPG a medical chart review was performed including demographics, ophthalmological examinations and magnetic resonance imaging (MRI) of OPG.

Results

Of 176 patients with NF1 (85 females, 91 males), we identified 21 patients with OPG (11.9%) with a preponderance of females, p = 0.184. Eight females (62%) and one male (13%) had visual impairment at the last ophthalmological evaluation. Five out of 21 children with OPG (24%) underwent diagnostic MRI because of clinical findings at the ophthalmological screening. Nine children (43%) had symptoms suggestive of OPG and seven (33%) experienced no OPG-related symptoms before the diagnostic MRI. Of eight children diagnosed with OPG ≤ two years of age, one had visual impairment. Of 13 children diagnosed > two years of age, eight had visual impairment; in each group, four of the children were treated with chemotherapy. The study suggested no correlation between NF1-OPG growth and sex.

Conclusion

Our data suggest sex as a risk factor for visual impairment, while an OPG diagnose ≤ two years of age was a protective factor for visual impairment. Females with NF1-OPG had a higher prevalence of visual impairment outcome compared to males. Interestingly, our data also suggest a better response to treatment in children with OPG diagnosed ≤ two years of age compared to older children. The findings in our study suggest sex as a potential prognostic factor for visual impairment.

Brain Cancers in Genetic Syndromes

PURPOSE OF REVIEW

Although genetic conditions that cause primary central nervous system tumors are rare, their pathophysiology influences both treatment and surveillance. This article reviews the most frequently occurring genetic conditions associated with brain cancers and highlights the most recent therapeutic approaches in the treatment of Lynch syndrome (and other disorders of the mismatch repair system), neurofibromatosis 1, and Li-Fraumeni syndrome.

RECENT FINDINGS

Recent advances in molecular diagnostics have considerably improved the ability to diagnose genetic conditions in people with primary brain tumors. The common application of next-generation sequencing analyses of tissue increases the frequency with which clinicians are forced to address the possibility of an underlying genetic condition based on tissue molecular findings. Clinicians must be aware of the clinical presentation of genetic conditions predisposing to brain tumors in order to discern which patients are appropriate for germline genetic testing. Advances in therapeutics for specific genetic variants are increasingly available, and accurately diagnosing an underlying genetic condition may directly impact patient outcomes.

Impact of systemic anticancer therapy in pediatric optic pathway glioma on visual function: A systematic review

Pediatric optic pathway glioma (OPG) can seriously decrease visual function in the case of progression. Systemic anticancer therapy (SAT) is considered the treatment of first choice for unresectable OPG. New SAT modalities for the treatment of progressive OPG have been introduced in the last decade, including VEGF and MAPK pathway inhibition. This systematic review evaluated the effect of SAT on change in visual acuity and visual field in OPG. A systematic review was performed on SAT for OPG (January 1990 to August 2020). MEDLINE and EMBASE (Ovid) were searched for studies reporting on change in visual acuity and visual field after treatment with SAT for OPG. Overall, 11 series, including 358 patients, fulfilled the eligibility criteria. After follow-up of median 3.7 years (range: cessation of SAT- 8.2 years), improvement in binocular VA was found in 0-45% of studies, stability in 18-77% and a decrease in 0-82%. Two studies reported on change in visual field (improvement in 19% and 71% of patients), although either the change was not defined or the testing strategy was lacking. Considerable heterogeneity was present among the included studies, such as variety in the combinations of SAT administered, status of neurofibromatosis type 1, definition regarding change in visual acuity, 1- or 2-eye analysis, diversity in anatomic location, and extent of follow-up, all of which made meta-analysis inappropriate. This systematic review suggests that the impact of SAT in OPG on visual function is still unclear. The wide ranges reported on the efficacy of SAT and the observed heterogeneity highlight the need for prospective studies with uniform definitions of outcome parameters.

Neurofibromatosis: Molecular Pathogenesis and Natural Compounds as Potential Treatments

The neurofibromatosis syndromes, including NF1, NF2, and schwannomatosis, are tumor suppressor syndromes characterized by multiple nervous system tumors, particularly Schwann cell neoplasms. NF-related tumors are mainly treated by surgery, and some of them have been treated by but are refractory to conventional chemotherapy. Recent advances in molecular genetics and genomics alongside the development of multiple animal models have provided a better understanding of NF tumor biology and facilitated target identification and therapeutic evaluation. Many targeted therapies have been evaluated in preclinical models and patients with limited success. One major advance is the FDA approval of the MEK inhibitor selumetinib for the treatment of NF1-associated plexiform neurofibroma. Due to their anti-neoplastic, antioxidant, and anti-inflammatory properties, selected natural compounds could be useful as a primary therapy or as an adjuvant therapy prior to or following surgery and/or radiation for patients with tumor predisposition syndromes, as patients often take them as dietary supplements and for health enhancement purposes. Here we review the natural compounds that have been evaluated in NF models. Some have demonstrated potent anti-tumor effects and may become viable treatments in the future.

Vision-related quality-of-life in pediatric primary brain tumor patients

PURPOSE

Brain tumors are the leading cause of death from childhood cancer. Although overall survival has improved due to earlier detection, better therapies, and improved surveillance, visual dysfunction and impaired vision-related quality-of-life (VR-QOL) are often unrecognized in children. This project investigated VR-QOL in pediatric brain tumor patients.

METHODS

We evaluated visual impairment and quality-of-life (QOL) in a quality improvement project at one tertiary care center. Patients ≤ 18, greater than 6 months from diagnosis of brain tumor, excluding intrinsic anterior visual pathway tumors, underwent standardized neuro-ophthalmologic examination. Health-related QOL (HR-QOL) (PedsQL Brain Tumor Module) and VR-QOL questionnaires [CVFQ (Children's Visual Function Questionnaire) in children < 8, and EYE-Q in children 8-18] were obtained from patients and parents.

RESULTS

Among 77 patients, craniopharyngiomas (n = 16, 21%) and astrocytomas (n = 15, 20%) were the most common tumors. Among 44/77 (57%) visually impaired children, 7 (16%) were legally blind. Eye-Q median score was 3.40 (interquartile range 3.00-3.75), worse than average scores for normal children. Eye-Q score decreased 0.12 with every 0.1 increase in logMAR visual acuity (p < 0.001). Patients who were legally blind had a significantly lower Eye-Q score than those who were not [0.70 vs. 3.44 (p < 0.001)]. Cognitive HR-QOL scores decreased 1.3 for every 0.1 increase in logMAR visual acuity (p = 0.02).

CONCLUSIONS

Pediatric brain tumor patients' vision, HR-QOL, and VR-QOL were often severely affected even when tumors were considered cured. Visual acuity and legal blindness correlated with VR-QOL. Systematic neuro-ophthalmologic examinations in pediatric primary brain tumor patients are necessary to facilitate early preventative and corrective ophthalmologic interventions.

[Imaging of tumor predisposition syndromes]

CLINICAL ISSUE

Tumor predisposition syndromes (TPS) are a heterogeneous group of genetic cancers. About 10% of the approximately 2200 malignancies in the childhood in Germany develop due to an inherited disposition, whereby TPS may be underdiagnosed. The focus of this review is set on imaging of Li-Fraumeni syndrome, neurofibromatoses, tuberous sclerosis, overgrowth, and neuroendocrine syndromes.

STANDARD RADIOLOGICAL METHODS

In order to detect tumors at an early stage, screening at specific time intervals for each TPS are required. Ultrasonography and magnetic resonance imaging (MRI), especially whole-body MRI, are particularly important imaging modalities.

METHODOLOGICAL INNOVATIONS

Innovative MRI techniques can increase image quality and patient comfort. MRI acquisition time can be significantly reduced through optimized acceleration factors, motion robust radial sequences and joint acquisition and readout of multiple slices during excitation. Thus, shorter MRI examinations can be performed in younger children without anesthesia.

PRACTICAL RECOMMENDATION

Regular screening with ultrasound and MRI can reduce the morbidity and mortality of the patients affected with TPS.

RETINAL VASCULAR ABNORMALITIES RELATED TO NEUROFIBROMATOSIS TYPE 1: Natural History and Classification by Optical Coherence Tomography Angiography in 473 Patients

PURPOSE

To analyze and classify neurofibromatosis Type 1 (NF1)-related retinal vascular abnormalities (RVAs), their natural history and correlation with disease severity, in a large cohort of patients.

METHODS

This was an observational longitudinal study with prospective enrollment. Four hundred and seventy-three patients affected by NF1 and 150 age-matched healthy subjects were consecutively enrolled. Retinal vascular abnormalities were detected by means of near-infrared reflectance and studied by optical coherence tomography angiography. The superficial vascular plexus and the deep vascular complex (DVC) were quantitatively and qualitatively analyzed.

RESULTS

We identified RVAs in 82 of 473 (17%) NF1 patients, but in none of the 150 healthy subjects. A comparison revealed that NF1 patients with RVAs showed a higher number of NF1 diagnostic criteria (4.3 ± 1.5 vs. 3.9 ±1.5, respectively; P = 0.02) than patients without RVAs. Three different RVA types were identified on optical coherence tomography angiography: macrovascular angiomatosis of the sole superficial vascular plexus; macrovascular angiomatosis of the superficial vascular plexus combined with microvascular angiomatosis of the deep vascular complex; and combined macrovascular angiomatosis of both superficial vascular plexus and deep vascular complex. The prospective analysis of optical coherence tomography angiography images showed no significant longitudinal evolution of RVAs (mean follow-up: 3.7 ± 2.8 years). A single patient developed a de novo single RVA, and two RVAs showed detectable changes during follow-up.

CONCLUSION

In NF1 patients, RVAs are a characteristic sign that correlates with a more severe systemic disease expression, usually remaining stable during time. Optical coherence tomography angiography allows for the identification of different RVAs subtypes.