Neuropsychological outcome in children with optic pathway tumours when first-line treatment is chemotherapy

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.

Neurofibromatosis type1, type 2, tuberous sclerosis and Von Hippel-Lindau disease

Neurocutaneous syndromes (also known as phakomatoses) are heterogenous group of disorders that involve derivatives of the neuroectoderm. Each disease has diagnostic and pathognomonic criteria, once identified, thorough clinical examination to the patient and the family members should be done. Magnetic resonance imaging (MRI) is used to study the pathognomonic findings withing the CNS (Evans et al. in Am J Med Genet A 152A:327-332, 2010). This chapter includes the 4 most common syndromes faced by neurosurgeons and neurologists; neurofibromatosis types 1 and 2, tuberous sclerosis and Von Hippel-Lindau disease. Each syndrome has specific genetic anomaly that involves a tumor suppressor gene and the loss of inhibition of specific pathways. The result is a spectrum of cutaneous manifestations and neoplasms.

Optic Pathway Gliomas: The Trends of Basic Research to Reduce the Impact of the Disease on Visual Function

Pediatric optic pathway gliomas (OPG) are low-grade brain tumors characterized by slow progression and invalidating visual loss. Common therapeutic strategies include surgery, radiotherapy, chemotherapy, and combinations of these modalities, but despite the different treatment strategies, no actual treatment exists to prevent or revert visual impairment. Nowadays, several reports of the literature show promising results regarding NGF eye drop instillation and improvement of visual outcome. Such results seem to be related with the NGF-linked prevention in caspase activation, which reduces retinal ganglion cell loss.Reducing retinal ganglion cell loss results clinically in visual field improvement as well as visual electric potential and optical coherence tomography gain. Nonetheless, visual acuity fails to show significant changes.Visual impairment represents nowadays one of the major issues in dealing with OPGs. Secondary to the interesting results offered by NGF eye drop administration, further studies are warranted to better comprehend potential treatment strategies.

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.

Recent Updates on Radiation Therapy for Pediatric Optic Pathway Glioma

Optic pathway glioma (OPG) is a rare tumor located in optic nerve, optic tract, or optic chiasm. Treatment options for OPG include surgery, radiation therapy (RT), and chemotherapy. Although RT may provide favorable long-term outcomes in manner of either adjuvant or salvage aim, chemotherapy-first approach is increasingly performed due to possible late effects of RT. Proton beam RT may allow normal tissue sparing of radiation exposure compared to conventional X-ray treatment. Therefore, proton beam RT is expected to reduce complications from RT. This review discusses the recent updates on oncologic outcomes of OPG, late toxicities following RT, and compares the outcomes between X-ray treatment and proton beam RT.

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.

Gamma Knife Radiosurgery in the Management of Hypothalamic Glioma: A Case Report with Long-Term Follow-Up

BACKGROUND

Optic pathway/hypothalamic gliomas are rare pediatric brain tumors. The management paradigm for these challenging tumors includes chemotherapy, radiotherapy, or surgical resection, but the optimal management strategy remains elusive. Gamma knife radiosurgery (GKRS) has emerged as a promising treatment for such lesions as documented by a small number of cases in the literature.

CASE PRESENTATION

We present a rare case of hypothalamic glioma in a 13-year-old girl who was referred to our service due to growth of an incidentally diagnosed hypothalamic lesion following head injury at the age of 8 years. The lesion demonstrated hypointensity on T1- and hyperintensity on T2-weighted imaging without contrast enhancement. Given the growth of the lesion on serial imaging, a stereotactic biopsy was performed demonstrating low-grade glioma. The patient underwent GKRS treatment with a marginal dose of 15 Gy at 50% isodose line for a tumor volume of 2.2 mL. Annual radiological surveillance over the next 17 years demonstrated a gradual shrinkage of the lesion until it completely disappeared. The patient is currently a healthy 31-year-old female without any visual, endocrine, or neurocognitive deficits.

CONCLUSION

The outcome obtained after extended follow-up in our patient highlights the safety and efficacy of GKRS in the management of hypothalamic gliomas in pediatrics, which in turn can avoid potentially serious complications of surgery in this vulnerable patient population, especially in this sensitive location.

Treatment and Long-Term Sequelae in Childhood Brain Tumors

In children treated for brain tumors, important deficits in cognitive development have been described. The reduction of Intelligence Quotient (IQ) is correlated with multiple conditions such as tumor location, obstructive hydrocephalus, surgical intervention, and above all, the use of radiotherapy, especially in young children. Demyelinization represents the most striking microscopic alteration following radiation: cerebral white matter’s loss and failure to white matter development could partly account for changes in IQ score.

Recently, combined chemo-radiotherapeutic approaches and the improvement of radiotherapy techniques have enabled the reduction of neurocognitive symptoms and improved the standard of life of childhood brain tumor survivors.

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.

Neuropsychological outcomes of children with Optic Pathway Glioma

Optic Pathway Glioma (OPG) is a relatively common brain tumour in childhood; however, there is scarce understanding of neuropsychological sequelae in these survivors. In this study, 12 children with diagnosis of OPG before 6 years of age received a comprehensive standardised assessment of visual perception, general intelligence and academic achievement, using adjustments to visual materials of the tests, to examine the extent of concurrent impairment in these functional domains. Information about vision, clinical and socio-demographic factors were extracted from medical records to assess the associations of neuropsychological outcomes with clinical and socio-demographic factors. Children with OPG exhibited high within-patient variability and moderate group-level impairment compared to test norms. Visual perception was the most impaired domain, while scholastic progression was age-appropriate overall. For cognition, core verbal and visuo-spatial reasoning skills were intact, whereas deficits were found in working memory and processing speed. Visual function was associated with tasks that rely on visual input. Children with OPG are at moderate risk of neuropsychological impairment, especially for visual perception and cognitive proficiency. Future research should elucidate further the relative contribution of vision loss and neurofibromatosis type 1 co-diagnosis within a large sample.

Brain Tumors in NF1 Children: Influence on Neurocognitive and Behavioral Outcome

Neurofibromatosis type-1 (NF1) is a monogenic tumor-predisposition syndrome creating a wide variety of cognitive and behavioral abnormalities, such as decrease in cognitive functioning, deficits in visuospatial processing, attention, and social functioning. NF1 patients are at risk to develop neurofibromas and other tumors, such as optic pathway gliomas and other tumors of the central nervous system. Few studies have investigated the impact of an additional diagnosis of brain tumor on the cognitive outcome of children with NF1, showing unclear results and without controlling by the effect of surgery, radio- or chemotherapy. In the present mono-institutional study, we compared the behavioral and cognitive outcomes of 26 children with neurofibromatosis alone (NF1) with two age-matched groups of 26 children diagnosed with NF1 and untreated optic pathway glioma (NF1 + OPG) and 19 children with NF1 and untreated other central nervous system tumors (NF1 + CT). NF1 + CT and NF1 + OPG showed significantly impaired cognitive abilities compared to NF1 group, with weaknesses in visuo-spatial abilities, visual scanning and verbal working memory, while general verbal abilities are preserved. Moreover, NF1 + OPG patients present more frequent internalizing problems and increased oppositional-deviant behaviors. These results suggest that the co-diagnosis of a brain tumor in NF1 children may partially worsen the cognitive and emotional outcome.

Current treatment of optic nerve gliomas

PURPOSE OF REVIEW

Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm, optic tracts and radiations and can either be sporadic or associated with neurofibromatosis type one. Gliomas isolated to the optic nerve (ONG) represent a subgroup of optic pathway gliomas, and their treatment remains controversial. New developments in ONG treatment have emerged in recent years, and it is necessary for clinicians to have a current understanding of available therapies.

RECENT FINDINGS

The current review of the literature covers the background of and recent developments in ONG treatment, with a focus on standard chemotherapy, new molecularly targeted therapies, radiation therapy and surgical resection and debulking.

SUMMARY

Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.

Systematic Review and Meta-analysis of Executive Functions in Preschool and School-Age Children With Neurofibromatosis Type 1

OBJECTIVES

Neurofibromatosis type 1 (NF1) is a genetic disorder in which the most frequent complication in children is learning disabilities. Over the past decade, growing arguments support the idea that executive dysfunction is a core deficit in children with NF1. However, some data remain inconsistent. The aim of this study was to determine the magnitude of impairment for each executive function (EF) and clarify the impact of methodological choices and participant's characteristics on EFs.

METHODS

In this meta-analysis, 19 studies met the selection criteria and were included with data from a total of 805 children with NF1 and 667 controls. Based on the Diamond's model (2013), EF measures were coded separately according to the following EF components: working memory, inhibitory control, cognitive flexibility, planning/problem solving. The review protocol was registered with PROSPERO (International prospective register of systematic reviews; CRD42017068808).

RESULTS

A significant executive dysfunction in children with NF1 is demonstrated. Subgroup analysis showed that the impairment varied as a function of the specific component of executive functioning. The effect size for working memory and planning/problem solving was moderate whereas it was small for inhibitory control and cognitive flexibility. Executive dysfunction seems to be greater with increasing age whereas assessment tool type, intellectual performance, attention deficit hyperactivity disorder and control group composition did not seem to affect EF results.

CONCLUSIONS

EF deficits are a core feature in children with NF1 and an early identification of executive dysfunctions is essential to limit their impact on the quality of life. (JINS, 2018, 24, 977-994).

Ophthalmic manifestations in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a relatively common multisystemic inherited disease and has been extensively studied by multiple disciplines. Although genetic testing and confirmation are available, NF1 remains a clinical diagnosis. Many manifestations of NF1 involve the eye and orbit, and the ophthalmologist, therefore, plays a significant role in the diagnosis and treatment of NF1 patients. Improvements in diagnostic and imaging instruments have provided new insight to study the ophthalmic manifestations of the disease. We provide a comprehensive and up-to-date overview of the ocular and orbital manifestations of NF1.

Management of pediatric intracranial low-grade gliomas: long-term follow-up after radiation therapy

INTRODUCTION

The treatment of pediatric intracranial low-grade gliomas (LGG) generally begins with maximal safe resection. Radiation therapy (RT) and chemotherapy are typically reserved for patients with incomplete resection and/or disease progression. We report long-term treatment outcomes and toxicities in a cohort of pediatric patients with LGG after RT.

METHODS

Thirty-four patients <21 years old with intracranial LGG who were treated with RT at the Johns Hopkins Hospital were included in this retrospective analysis. Patients were evaluated for overall survival (OS), progression-free survival (PFS), recurrence patterns, and treatment toxicities using descriptive statistics, Kaplan-Meier curves, and Cox proportional hazard regressions.

RESULTS

The mean age at diagnosis was 7.9 years (range 1.2-18.3 years) and mean age at RT was 9.8 years (range 3.0-28.9 years). The median follow-up time was 9.8 years after radiation (range 0.8-33.3 years). The estimated 10-year OS and PFS after RT were 92 and 74 %, respectively. Twelve patients had disease progression after RT, and all recurrences were local. Two patients died due to disease progression 2.3 and 9.1 years after RT. One patient had malignant transformation of LGG to high-grade glioma. No significant predictors of PFS were identified on uni- or multivariate analysis. Late effects of LGG and treatment seen were endocrine deficiencies in 16 patients, visual problems in 10 patients, hearing loss in 4 patients, special education requirements for 5 patients, and a vascular injury/demyelination secondary to RT in 1 patient.

CONCLUSION

Our study suggests that the use of radiation in patients with intracranial LGG results in excellent OS and PFS with acceptable toxicity at long-term follow-up.

Optic pathway glioma in children: does visual deficit correlate with radiology in focal exophytic lesions?

PURPOSE

Unlike pilocytic astrocytomas in other parts of the brain, optic pathway gliomas (OPG) are usually diffuse lesions involving the anterior optic pathways and hypothalamus. Their infiltrative nature often precludes complete surgical resection. We sought to determine whether careful magnetic resonance (MR) analysis, correlated with visual deficits, could be sufficient to identify those focal lesions that may be amenable to more aggressive surgical resection at presentation.

METHODS

We retrospectively reviewed the medical records of patients from two sites: children under 20 years of age treated for OPG between 1985 and 2009 at St Jude's Children's Research Hospital and children under 16 years of age treated at Great Ormond Street Hospital, London, UK, between 1984 and 2011. Patients with isolated optic nerve tumors were excluded. Visual acuity and visual field data at presentation were reviewed and correlated with MR characteristics, including extent of optic pathway involvement, symmetry, and lateral extension.

RESULTS

Two hundred and one children were treated for OPG between 1984 and 2011 in the two institutions; 74 had neurofibromatosis 1 (NF1). At presentation, visual loss was symmetrical in 132 patients and asymmetrical in 69. Potential correlation between pattern of visual loss and tumor characteristics on routine MRI was found in only 13 patients with asymmetrical vision. There was no difference between patients with and without NF1.

CONCLUSION

The decision for aggressive surgical resection for optic pathway gliomas should be based on clinical criteria, particularly in children with good vision in one eye and poor vision in the other, as current MRI results do not reliably predict visual field deficits.

Optic pathway gliomas

Optic pathway gliomas (OPGs) are among the most challenging neoplasms in modern pediatric neuro-oncology. Recent technological advances in imaging, surgery, and chemotherapy may lead to better understanding of the pathophysiology and better clinical results. This chapter reviews these advances and the current treatment paradigms.

Gliomas in children

OPINION STATEMENT

Gliomas are the most common brain tumor in children and represent nearly 50 % of all pediatric central nervous system (CNS) tumors. They are a heterogeneous group of diseases, ranging from highly malignant and frequently fatal to histologically benign and curable by surgery alone. A uniform treatment approach to these tumors is not practical, due to their histological and biological heterogeneity. Low-grade gliomas (LGGs) are best treated with maximally safe surgical resection, generally achievable for hemispheric or cerebellar locations. Patients with deep midline, optic pathway/hypothalamic, and brain stem locations should undergo subtotal resection or biopsy only. If a complete resection is not feasible, subtotal resection followed by adjuvant chemotherapy or radiotherapy is the standard approach; however, observation alone with serial neuroimaging is used in some asymptomatic, surgically inaccessible lesions. Chemotherapy is used first-line in cases of residual or progressive disease, to avoid or delay radiation therapy and its associated side effects. Regimens demonstrating objective responses and increased progression free survival (PFS) include carboplatin and vincristine (CV), thioguanine/procarbazine/CCNU/vincristine (TPCV), or weekly vinblastine. High-grade gliomas (HGGs) are less common in children than in adults, though are similar in their aggressive clinical behavior, resistance to therapy, and dismal outcomes. There is not a single "standard of care" therapy for non-metastatic HGGs, but generally accepted is an aggressive attempt at a complete surgical resection, followed by multimodality therapy with focal radiation and chemotherapy. The use of temozolomide (TMZ) during and following radiotherapy is common, though it appeared not to improve the outcome in a cooperative group clinical trial when compared to an historical control cohort. The angiogenesis inhibitor bevacizumab, used alone or in combination with irinotecan, is also commonly used as maintenance therapy after radiation. Current trials are prospectively comparing TMZ to newer agents (vorinostat, bevacizumab) in a randomized phase II trial. Brainstem gliomas are a unique category of childhood gliomas. Approximately 80 % of childhood brainstem gliomas arise within the pons as diffuse intrinsic pontine gliomas (DIPG). When biopsied, these are usually HGGs and carry a dismal prognosis. Standard therapy is focal radiation (54-58 Gy), preferably on a clinical trial testing concurrent chemotherapy or biologic agent. No standard chemotherapy agent has impacted survival. The remaining 20 % of brainstem gliomas are low-grade, arise in the midbrain, dorsal medulla, or cervicomedullary junction, and are indolent in nature with a much better prognosis. Improvement in the outcome of all childhood gliomas will require increased knowledge of the underlying biology of these tumors, in order to treat with more biologically based and precise therapies.

Neurocognitive consequences of a paediatric brain tumour and its treatment: a meta-analysis

AIM

This meta-analysis provides a systematic review of studies into intellectual and attentional functioning of paediatric brain tumour survivors (PBTS) as assessed by two widely used measures: the Wechsler Intelligence Scale for Children (3rd edition; WISC-III) and the Conners' Continuous Performance Test (CPT).

METHOD

Studies were located that reported on performance of PBTS (age range 6-16y). Meta-analytic effect sizes were calculated for Full-scale IQ, Performance IQ, and Verbal IQ as measured by the WISC-III, and mean hit reaction time, errors of omission, and errors of commission as measured by the CPT. Exploratory analyses investigated the possible impacts of treatment mode, tumour location, age at diagnosis, and time since diagnosis on intelligence.

RESULTS

Twenty-nine studies were included: 22 reported on the WISC-III in 710 PBTS and seven on CPT results in 372 PBTS. PBTS performed below average (p(s) <0.001) on Full-scale IQ (Cohen's d=-0.79), Performance IQ (d=-0.90), and Verbal IQ (d=-0.54). PBTS committed more errors of omission than the norm (d=0.82, p<0.001); no differences were found for mean hit reaction time and errors of commission. Cranial radiotherapy, chemotherapy, and longer time since diagnosis were associated with lower WISC-III scores (p(s) <0.05).

INTERPRETATION

PBTS have seriously impaired intellectual functioning and attentiveness. Being treated with cranial radiotherapy and/or chemotherapy as well as longer time since diagnosis leads to worse intellectual functioning.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Long-term follow-up of the multicenter, multidisciplinary treatment study HIT-LGG-1996 for low-grade glioma in children and adolescents of the German Speaking Society of Pediatric Oncology and Hematology

The Hirntumorstudien (HIT)-LGG-1996 protocol offered a comprehensive treatment strategy for pediatric patients with low-grade glioma (LGG), ie, observation, surgery, adjuvant radiotherapy, and chemotherapy to defer the start of irradiation in young children. In this current study, we sought to determine clinical factors for progression and survival. Between October 1, 1996 and March 31, 2004, 1031 patients were prospectively recruited into an observation arm (n = 668) and a nonsurgical arm stratifying 12 months of vincristine-carboplatin chemotherapy (n = 216) and conventional radiotherapy/brachytherapy (n = 147) in an age-dependent manner. Median patient age was 6.9 years; 28 patients had diencephalic syndrome, 44 had dissemination, and 108 had neurofibromatosis type 1(NF-1). Main tumor location was the supratentorial midline (40.4%), and the main histology was pilocytic astrocytoma (67.9%). Following a median observation of 9.3 years, 10-year overall survival (OS) was 0.94 and 10-year event-free survival (EFS) was 0.47. Ten-year progression-free survival was 0.62 following radiotherapy and 0.44 following chemotherapy. Sixty-one of 216 chemotherapy patients received radiotherapy 0.3-8.7 years after initial diagnosis. By multivariate analysis, diencephalic syndrome and incomplete resection were found to be unfavorable factors for OS and EFS, age ≥11 years for OS, and supratentorial midline location for EFS. Dissemination, age <1 year, and nonpilocytic histology were unfavorable factors for progression following radiotherapy (138 patients); and diencephalic syndrome, dissemination, and age ≥11 years were unfavorable factors following chemotherapy (210 patients). NF-1 patients and boys experienced prolonged tumor stabilization with chemotherapy. A nationwide multimodal treatment strategy is feasible for pediatric LGG. Extended follow-up yielded results comparable to single-institution series for the treatment groups. Three-quarters of surviving chemotherapy patients have not yet received radiation therapy. Infants with or without diencephalic syndrome and dissemination bear the highest risk for death and progression following diagnosis or treatment.

Pediatric low-grade gliomas

Pediatric low-grade gliomas encompass a heterogeneous set of tumors of different histologies. Cerebellar pilocytic astrocytomas occur most frequently followed by supratentorial diffuse fibrillary astrocytomas. Recent research has implicated activation of the RAS/RAF/MEK pathway in tumorigenesis of these tumors. Surgery is the mainstay of therapy. Overall survival rates for patients whose tumors are completely resected are 90% or greater, 10 years from diagnosis. Conversely, most optic pathway/hypothalamic, deep midline, and brain stem gliomas have minimal potential for resection; these tumors can be difficult to treat and deserve special attention. Combination chemotherapy is currently recommended as front-line adjuvant treatment for progressive or recurrent tumors. Second-line radiotherapy can also improve overall survival but is associated with more frequent and significant neurocognitive, endocrine, and other long-term toxicities.

Cognitive Deficits and Predictors 3 Years After Diagnosis of a Pilocytic Astrocytoma in Childhood

Purpose

To prospectively study cognitive deficits and predictors 3 years after diagnosis in a large series of pediatric patients treated for pilocytic astrocytoma (PA).

Patients and Methods

Sixty-one of 67 children were grouped according to infratentorial, supratentorial midline, and supratentorial hemispheric site. Intelligence, memory, attention, language, visual-spatial, and executive functions were assessed. Included predictors were sex, age, relapse, diagnosis-assessment interval, hydrocephalus, kind of treatment, and tumor variables.

Results

All children with PA had problems with sustained attention and speed. In the infratentorial group, there also were deficits in verbal intelligence, visual-spatial memory, executive functioning, and naming. Verbal intelligence and verbal memory problems occurred in the brainstem tumor group. The supratentorial hemispheric tumor group had additional problems with selective attention and executive functioning, and the supratentorial midline tumor group displayed no extra impairments. More specifically, the dorsal supratentorial midline tumor group displayed problems with language and verbal memory. Predictors for lower cognitive functioning were hydrocephalus, radiotherapy, residual tumor size, and age; predictors for better functioning were chemotherapy or treatment of hydrocephalus. Almost 60% of children had problems with academic achievement, for which risk factors were relapse and younger age at diagnosis.

Conclusion

Despite normal intelligence at long-term follow-up, children treated for PA display invalidating cognitive impairments. Adequate treatment of hydrocephalus is important for a more favorable long-term cognitive outcome. Even children without initial severe deficits may develop cognitive impairments years after diagnosis, partly because of the phenomenon of growing into deficit, which has devastating implications for academic achievement and quality of life (QOL).

Anterior Visual Pathway Gliomas: The Last 30 Years

Modern neuroimaging provides excellent characterization of anterior visual pathway gliomas, often obviating the need for biopsy of the tumor. Management remains controversial, but if there is progression, chemotherapy is preferred for young patients. Stereotactically guided conformal radiotherapy and proton beam radiotherapy allow smaller, more precise doses of radiation to be administered and can be considered in older children with progressive disease. A mouse model of NF-1 with optic pathway gliomas has the potential to provide important insights into the development of gliomas as well as serving as a model for their effective treatment.

Cognition before and after chemotherapy alone in children with chiasmatic-hypothalamic tumors

Studies on adults with cancer, with or without CNS involvement, have shown that chemotherapy (CT) can affect cognitive functions. Two studies on children with optic pathway gliomas, involving the hypothalamus in some cases, and treated with CT according to various protocols reported the children maintaining a good IQ (no other cognitive abilities were tested). Among 18 children with chiasmatic-hypothalamic tumors (CHT) given front-line CT treatment at our institute using the same protocol (cisplatin and etoposide), we screened eight children for cognitive sequelae, correlating their test performance with several clinical variables (age at diagnosis and at time of treatment, time elapsing since treatment, and tumor volume reduction). The neuropsychological evaluation involved measuring IQ in all eight children and cognitive flexibility in three before CT (T1), then testing IQ, attention, memory and executive functions after CT (T2). The group as a whole showed no signs of any decline in IQ from T1 to T2, except for some WISC items, but IQ deteriorated severely in three patients with NF1 (only suspected in one case). At T2, the whole sample performed within normal range, except for two children showing a significantly worse result in two specific tests. The parents of the other 10 children, reported no substantial changes in their children's behavior and intellectual vivacity in a semistructured telephone interview conducted in cooperation with the children's teachers. CT alone as front-line treatment for CHT does not appear to have a negative effect on IQ and numerous neuropsychological tests. Some skills were more affected than others in our sample (albeit with a very low statistical significance of the impairment), and some patients seemed to be more vulnerable than others after CT. The multifactorial origin of such cognitive impairments is discussed. This type of study needs to be repeated in larger, but nonetheless carefully selected groups of patients.

Preventing neurocognitive late effects in childhood cancer survivors

Neurocognitive late effects are common sequelae of cancer in children, especially in those who have undergone treatment for brain tumors or in those receiving prophylactic cranial radiation therapy to treat leukemia. Neurocognitive morbidity in attention, executive functioning, processing speed, working memory, and memory frequently occurs and contributes to declines in intellectual and academic abilities. Oncologists are faced with the challenge of using the most effective, often the most intense, therapy to achieve the primary goal of medical success, balanced with the desire to prevent adverse late effects. Not all children with similar diagnoses and treatment have identical neurocognitive outcomes; some do very poorly and some do well. Attention now turns to the reliable prediction of risk for poor outcomes and then, using risk-adapted therapy, to preserve neurocognitive function. Prevention of late effects through rehabilitative strategies, continuation of school, and pharmacotherapy will be explored.

Role of surgery for optic pathway/hypothalamic astrocytomas in children

Optic pathway/hypothalamic pilocytic astrocytomas in children are usually treated with chemotherapy following a surgical biopsy. In this report, we retrospectively considered the role of surgical intervention. In a series of 25 patients without neurofibromatosis type 1, the median age at initial treatment was 3.1 years (range, 0-15 years). Twenty cases were verified by histology, and five cases were diagnosed by MRI findings. Twenty-three patients received chemotherapy. All patients were alive at median follow-up of 66 months. Aims of surgery at the initiation of treatment were biopsy in 12 cases (1 stereotactic and 11 craniotomies) and debulking in 7 cases. The 11 open biopsies revealed pilocytic astrocytoma; however, noticeable complications occurred in five children after the biopsies. Review of preoperative MRIs showed that all had typical findings indicating pilocytic astrocytoma. The open biopsy offered no noteworthy benefit for the patients despite surgical risk and delay of chemotherapy. The extent of the seven resection surgeries was 70% or less removal, and postoperative adjuvant therapy was needed for six of the seven patients. The remaining six children who did not undergo surgery obtained remission with chemotherapy alone. After relapse in nine patients, 15 bulk-reduction surgeries were performed. Surgical resection was not curative in any patient. In five patients, mostly older children, cystic expansion of tumor was partially resected, resulting in additional remission. In conclusion, considering the risk of open surgery and the effectiveness of chemotherapy, the role of surgical intervention is restricted to bulk-reduction surgery only when it is inevitable, especially at relapse after chemotherapy.

Management of optic-hypothalamic gliomas in children: still a challenging problem

Optic pathway-hypothalamic gliomas (OPHGs) are rare, often unresectable tumors that mostly occur in childhood. Their biological behavior is unpredictable, although they tend to follow an aggressive clinical course in infants and a benign course in children with neurofibromatosis type 1. Optimal management is still controversial. Nonprogressing OPHGs are usually followed by surveillance alone. Surgery is advocated for progressing tumors to decompress the optic pathways, obtain a quick relief from intracranial hypertension and allow histologic examination (when needed). The current trend is in favor of conservative surgical behavior, except for resectable tumors. Chemotherapy is increasingly used in the management of OPHGs, especially in infants, to delay radiotherapy. Carboplatin and vincristine are the most frequently used drugs, although several chemotherapeutic agents in different combinations are currently employed with good results. Radiotherapy is utilized in children over 5 years of age as an adjuvant or as an alternative to surgery. The prognosis of OPHGs is quite good, with regard to the overall survival rate (70-100% at 5 years), but less favorable in terms of late morbidity.

Remediation of learning difficulties in children after treatment for a cerebellar medulloblastoma: a single-case study

In the process of establishing a methodology for individualized remediation programmes in children treated for cerebellar tumour, this study followed prospectively over 11 years a young child treated for a medulloblastoma at 18 months of age throughout the rehabilitation process. Repeated neuropsychological and academic evaluations evidenced temporary disruptive behaviour, deficient manual and visual abilities, attention and working memory difficulties, but preserved language abilities, in relation with vermian and left cerebellar damage. However, the described remediation programmes and interventions allowed the child to have fluent progression in school. Limits and benefits of rehabilitation are discussed.

Syndromic and sporadic pediatric optic pathway gliomas: review of clinical and histopathological differences and treatment implications

✓Optic pathway gliomas (OPGs) are the most common primary neoplasm of the optic pathway. These lesions usually present in childhood and can arise anywhere along the optic pathway; they occur more frequently in women; and they rarely undergo late progression. Management strategies after the initial diagnosis are controversial, compounded by the different behaviors exhibited by sporadic and syndromic tumors. Neurofibromatosis Type 1 (NF1), with aberrant oncogenic signaling and consequent predisposition to intracranial tumors, is the most common associated syndrome, with nearly 20% of NF1 patients developing OPGs. A comorbid NF1 diagnosis has implications for tumor location with greater predilection for optic nerve involvement, whereas chiasmal and postchiasmal lesions are more frequently seen in sporadic cases. Syndromic OPGs often exhibit more indolent behavior and lower rates of clinical progression, and the majority of these are diagnosed by routine neuroophthalmological screening. When treatment is indicated, however, the molecular abnormalities that constitute this syndrome can limit the available chemotherapy and radiotherapy options because clinicians fear secondary malignancy and cerebrovascular complications. Furthermore, radiotherapy early in life can impair an individual's intellectual development, endocrine function, and physical growth, thereby limiting the role of this modality in the treatment of this childhood lesion. Differential gene expression and histogenesis among sporadic and syndromic OPGs may account for the different tumor behaviors, but studies correlating specific genetic and proteomic changes with patient outcome are pending. Loss of heterozygosity at 10 and 17q are more common among patients with NF1, and Ki67 labeling intensity of 2–3% and low p53 labeling intensity seem prognostic of aggressive tumor behavior. Recent advances in the development of a preclinical mouse model of NF1-associated OPG will permit investigation into improved detection strategies and chemotherapeutic and radiotherapy treatment protocols.

Optic pathway gliomas: a review

✓Optic pathway gliomas represent approximately 3–5% of childhood intracranial tumors. They usually occur in children during the first decade of life and are seen in 11–30% of patients with neurofibromatosis Type 1 (NF1). Although these tumors are typically low-grade gliomas, the clinical course and natural history are highly variable, making treatment paradigms difficult. Overall, however, they are often indolent tumors that can be observed over time for progression without initial treatment, especially in patients with NF1. Chemotherapy is the first-line treatment for progressive tumors, and radiation therapy is reserved for patients with progressive disease who are older than 5–7 years. Surgery is reserved for large tumors causing mass effect or hydrocephalus and tumors confined to the orbit or unilateral optic nerve.

Optic pathway gliomas

Optic pathway gliomas represent approximately 5% of all pediatric intracranial tumors. While these tumors are most frequently low grade astrocytomas, they follow a highly variable clinical course, and accordingly, there is much debate regarding their optimal management. Their propensity to occur in very young children and infants further complicates selection of therapy. Historically, surgery and radiotherapy have played a primary role in management, however, in the last 15 years, chemotherapy has evolved into the first-line treatment of choice. Nonetheless, chemotherapy frequently fails, but serves to delay implementation of radiotherapy or surgery until the child has progressed neuropsychologically. An overall favorable prognosis for this tumor emphasizes the need for careful selection of therapy. Herein, we review the major features of optic pathway glioma, including epidemiology, pathology, therapeutic interventions, outcome, and treatment sequelae.

Current approaches to CNS tumors in infants and very young children

Treatment of infants and very young children with tumors of the CNS is challenging due to the vulnerability of the developing nervous system. Historically, treatment has relied upon surgery and radiation for control of malignant tumors with limited success and severe long-term consequences in most young patients. More recent studies have attempted to utilize chemotherapy and second-look surgery in attempts to reduce, delay or avoid radiation. Identification of prognostic factors for specific tumor types may distinguish which patients should receive more aggressive therapies and which patients can potentially avoid them and their potential side effects. Achieving successful tumor control while optimizing quality of life for survivors is the major goal of recent research.

Considerations on the Role of Chemotherapy and Modern Radiotherapy in the Treatment of Childhood Low Grade Glioma

The treatment of childhood low grade glioma (LGG), if not amenable to complete resection, quite often is a relevant clinical challenge. LGG in many instances are indeed slow growing tumors, which, if not controlled, can cause severe morbidity and ultimately jeopardize life. Most of the time children bearing an unresectable LGG can be considered affected by a chronic disease, deserving protracted cures. The treatment philosophy, which has dictated the treatment of malignant cancers, has also inspired the therapeutic concepts for managing childhood LGG. However, it is getting more and more evident that different strategies are needed for them. LGG represent a highly heterogeneous group of neoplasm and comprehensive treatment concepts rarely meet the individual patient's needs. After more than 20 years of clinical research it can be stated with confidence that for unresectable, progressive LGG, chemotherapy (CT) represents an effective treatment modality. It delays tumor growth and postpones the use of radiotherapy (RT), thus sparing the deleterious effects of irradiation on a developing brain. However, CT rarely cures LGG and definitively obviates the need of RT or aggressive surgery. Furthermore, little is known on the actual impact of CT on patients' overall health status. Recent progresses in RT delivering techniques, which allow reducing the safety margins, are tempering the concerns related to the use of this treatment modality in children. This manuscript reviews and expands these data, trying to combine them in a coherent picture that it is hoped can help in directing future research in this field.

Technology insight: Proton beam radiotherapy for treatment in pediatric brain tumors

Tumors of the central nervous system are the most common solid tumor in childhood. Treatment options for childhood brain tumors include radiation therapy, surgery and chemotherapy, often given in combination. Radiation therapy regularly has a pivotal role in treatment, and technological advancements during the past quarter of a century have dramatically improved the ability to deliver radiation in a more focused manner. Improvements in imaging and computing ability led to better targeting of tumor tissue using conventional X-ray therapy. These advances have been harnessed for proton radiation therapy. Proton radiotherapy has special physical characteristics that allow normal tissues to be spared better than even the most conformal photon radiation, and it will reduce the complications from treatment. This review discusses the characteristics of proton radiation, and describes examples of pediatric brain tumor patients who would benefit most from this form of treatment.

Brain tumors in children: evaluation and management

Brain and spinal cord tumors represent the most common solid tumors in children. Recent advances in imaging techniques, neurosurgical techniques, chemotherapy approaches, and radiation oncology have resulted in some improvement in overall survival and morbidity. However, the prognosis for many children with high-grade and malignant brain tumors remains guarded in terms of mortality and long-term sequelae. Given the rarity of tumors in children, patients are likely best served at tertiary center that can offer a comprehensive multidiscipline approach.

Neurocognitive Outcomes in Survivors of Childhood Cancer

OBJECTIVE

s To review issues associated with neurocognitive outcome in survivors of pediatric cancer. Recommendations are made for future research directions.

METHODS

A large body of literature pertaining to neurocognitive outcome in cancer survivors was reviewed. Brain development and methodological issues that provide challenges to conducting meaningful research in cancer outcomes also are discussed.

RESULTS

Neurotoxic agents used in some cancer therapies produce permanent neurocognitive sequelae, especially in very young children.

CONCLUSIONS

The state of neurocognitive research for pediatric cancer survivors needs to move beyond empirical studies of neurocognitive sequelae to research that will identify individual patients at risk for neurocognitive morbidity.

Measuring the neuro-cognitive side-effects of irradiation in children with brain tumors

BACKGROUND

Reduction of the treatment-related side effects has become one of the main goals of the recent study protocols for brain tumor therapies. When the treatment burden is decreased in patients with good prognostic features, the potential increased risk of relapse has to be counterbalanced by a significantly improved cognitive outcome. This objective is always clearly stated but comprehensive data on the neuropsychological outcomes are seldom reported.

PROCEDURES AND RESULTS

The appropriate means to measure the long-term morbidity need to be clarified. Health Status and Quality of Life (QOL) questionnaires can be easily administered but these questionnaires represent usually a composite evaluation where cognition is analyzed along with other items such as mood or pain. However, none of these questionnaires has ever been used to measure a difference in cognitive outcome when comparing two different therapeutic strategies in children. Complete neuropsychological evaluations are time consuming, need specialized psychologists and most of the tests have not been rigourously validated. In this respect, Wechsler scales are, however, robust and objective methods to evaluate intelligence. Several studies have been able to show meaningful differences in IQ scores between treatments in children with posterior fossa tumors, even with small numbers of patients.

CONCLUSIONS

In order to evaluate any refinement in the treatment of these patients, widely accepted evaluation tools are needed. Ideally, these methods will have to be sensitive, reproducible, and widely applicable. None of the available tools fullfil all of these criteria but their development should be a major endeavour in modern neuro-oncology.