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.

Pediatric Optic Pathway Gliomas: A Report From Northern Greece

Optic pathway gliomas (OPGs) are the most common pediatric optic nerve tumors. Their behavior ranges between rapid growth, stability, or spontaneous regression. Τhey are characterized by low mortality albeit with significant morbidity. We present the characteristics, management, and outcome of 23 OPG patients (16 females, median age: 4.8 y) managed in a Pediatric Oncology Department in Northern Greece over a 25-year period. Overall, 57% had a background of neurofibromatosis type 1. Diagnosis was based on imaging (10 patients) or biopsy (13 patients). Presenting symptoms were mostly visual impairment/squint (52%). Proptosis/exophthalmos, raised intracranial pressure, and headache were also noted. In 2 occasions, it was detected with surveillance magnetic resonance imaging in the context of neurofibromatosis type 1. Eight patients had unilateral and 2 bilateral optic nerve tumors (Modified Dodge Classification, stage 1a/1b), 3 had chiasmatic (stage 2a/b), and 10 had multiple tumors (stage 3/4). Predominant histology was pilocytic astrocytoma (77%). Management included: observation (4), chemotherapy only (9), surgery only (3), or various combinations (7). Chemotherapy regimens included vincristine and carboplatin, vinblastine, or bevacizumab with irinotecan. Most patients demonstrated a slow disease course with complete response/partial response to chemotherapy and/or surgery, whereas 39% presented ≥1 recurrences. After a median follow-up of 8.5 years (range to 19 y), 20 patients (87%) are still alive with stable disease, in partial/complete remission, or on treatment.

The Present and Future of Optic Pathway Glioma Therapy

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

Neurofibromatosis type 1-associated optic pathway gliomas: pathogenesis and emerging treatments

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder associated with an increased risk of developing a variety of benign and malignant tumors. Fifteen to 20% of children with NF1 are diagnosed with an optic pathway glioma (NF1-OPG) before 7 years of age, and more than half of them experience visual decline. At present, no effective therapy is available for prevention, restoration, or even stabilization of vision loss in subjects affected by NF1-OPG. This paper aims to review the main emerging pharmacological approaches that have been recently assessed in preclinical and clinical settings. We performed a search of the literature using Embase, PubMed, and Scopus databases to identify articles regarding NF1-OPGs and their treatment up to July 1st, 2022. The reference lists of the analyzed articles were also considered a source of literature information. To search and analyze all relevant English articles, the following keywords were used in various combinations: neurofibromatosis type 1, optic pathway glioma, chemotherapy, precision medicine, MEK inhibitors, VEGF, nerve growth factor. Over the past decade, basic research and the development of genetically engineered mice models of NF1-associated OPG have shed light on the cellular and molecular mechanisms underlying the disease and inspired animal and human testing of several compounds. A promising line of research is focusing on the inhibition of mTOR, a protein kinase controlling proliferation, protein synthesis rate and cell motility that is highly expressed in neoplastic cells. Several mTOR blockers have been tested in clinical trials, the most recent of which employed oral everolimus with encouraging results. A different strategy aims at restoring cAMP levels in neoplastic astrocytes and non-neoplastic neurons, since reduced intracellular cAMP levels contribute to OPG growth and, more importantly, are the major determinant of NF1-OPG-associated visual decline. So far, however, this approach has only been attempted in preclinical studies. Stroma-directed molecular therapies - seeking to target Nf1 heterozygous brain microglia and retinal ganglion cells (RGCs) - are another fascinating field. Microglia-inhibiting strategies have not yet reached clinical trials, but preclinical studies conducted over the last 15 years have provided convincing clues of their potential. The importance of NF1-mutant RGCs in the formation and progression of OPGs also holds promise for clinical translation. The evidence of Vascular Endothelial Growth Factor (VEGF)- Vascular Endothelial Growth Factor (VEGFR) signaling hyperactivity in pediatric low-grade gliomas prompted the use of bevacizumab, an anti-VEGF monoclonal antibody, which was tested in children with low-grade gliomas or OPGs with good clinical results. Neuroprotective agents have also been proposed to preserve and restore RGCs and topical eye administration of nerve growth factor (NGF) has demonstrated encouraging electrophysiological and clinical results in a double-blind, placebo-controlled study. Traditional chemotherapy in patients with NF1-OPGs does not significantly ameliorate visual function, and its effectiveness in halting tumor growth cannot be considered a satisfactory result. Newer lines of research should be pursued with the goal of stabilizing or improving the vision, rather than reducing tumor volume. The growing understanding of the unique cellular and molecular characteristics of NF1-OPG, coupled with the recent publication of promising clinical studies, raise hope for a shift towards precision medicine and targeted therapies as a first-line treatment.

Precocious and accelerated puberty in children with neurofibromatosis type 1: results from a close follow-up of a cohort of 45 patients

PURPOSE

Central precocious puberty (CPP) in neurofibromatosis type 1 (NF1) occurs mainly in association with optic pathway glioma (OPG), but it can also develop in the absence of OPG. The aim of this study was to analyze the prevalence of puberty disorders in children with NF1 and its association with OPG and its location.

METHODS

A retrospective study of 45 children with NF1 (68.9% boys) followed at our center between 2008 and 2020 was conducted. A cerebral MRI scan was performed in all children. We analyzed auxological, laboratory, and imaging data of children with CPP or accelerated puberty (AP). Treatments used for CPP/AP and their effect on height were also evaluated.

RESULTS

The prevalence of puberty disorders in our cohort was 17.8% (male to female ratio of 7:1). CPP and AP were diagnosed in 8/45 (17.8%) NF1 children. Among children with puberty disorders, 5/8 (62.5%) had an OPG with chiasm involvement, 1/8 (12.5%) had an isolated optic nerve tumor, and 2/8 (25%) did not have any evidence of OPG on MRI. Fisher's exact test showed an association between CPP/AP and chiasm OPG (p = 0.025). Treatment with triptorrelin was initiated in 5/8 children, of whom four attained final predicted height.

CONCLUSION

Our study confirms the higher prevalence of CPP/AP in NF1 patients, as well as an association between chiasm OPG and puberty disorders. However, CPP/AP also occurred in the absence of OPG with an incidence of 9.1%. Comprehensive evaluation of every child with NF1 regardless of the presence of OPG is therefore essential.

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.

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.

Multiple sclerosis in a child with neurofibromatosis type I - clinical management of a challenging case

A 13-year-old girl with neurofibromastosis (NF1) was admitted to the Department of Paediatric Haematology, Oncology and Transplantology due to progressive vision loss in September 2018. The patient was diagnosed with optic nerve gliomas and chemotherapy was initiated. During the treatment, the girl experienced muscle weakness in the lower limbs, and uncharacteristic lesions were detected in the spinal cord. Eventually, the girl was diagnosed with MS. The described case is one of the few reports of a child with coexisting NF1 and MS. The coincidence of these diseases is unusual and requires a multidisciplinary approach. Vision impairment in patients suffering from NF1 is typically associated with optic nerve gliomas, although it can be caused by other factors, such as MS, which is proven to have a higher prevalence in the NF1 population. Extensive ophthalmological diagnostics may not be conclusive, thus there is a need for the thorough neurological evaluation of patients with NF1 and visual deficits.

Vision Outcomes for Pediatric Patients With Optic Pathway Gliomas Associated With Neurofibromatosis Type I: A Systematic Review of the Clinical Evidence

Children with neurofibromatosis type I (NF1) have a higher predisposition for low-grade astrocytomas of the optic pathway, commonly referred to as optic pathway gliomas (OPGs). OPGs can result in visual deterioration. Treatment outcomes in OPG-NF1 management are often reported around tumor stabilization. We sought to compare vision outcomes associated with different OPG treatment strategies to inform about this important functional metric. A meta-analysis exploring the different modalities to treat children with OPG-NF1 was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using multiple databases. Of the 113 articles identified in the search, 23 full text articles, representing 564 patients, were included for review. These articles included retrospective, prospective, and randomized controlled studies on observation (n=9), chemotherapy (n=19), radiation therapy (n=6), and surgery (n=7). Of the patients undergoing observation, 87% (60/69) demonstrated stable acuity. In the chemotherapy studies, 27.3% (72/264) demonstrated improved acuity/visual field and/or visual-evoked potential amplitudes, 39.4% (104/264) stable acuity, and 33.3% (88/264) deterioration. Both the radiation and surgical treatments reported worsening acuity at 90.9% (10/11) and 73.3% (11/15), respectively. Causal associations are not known. Indications for and timing of treatment choice warrant larger scale study to provide further understanding.

A systematic review of ongoing clinical trials in optic pathway gliomas

INTRODUCTION

Optic pathway gliomas (OPGs), also known as Visual Pathway Gliomas, are insidious, debilitating tumours. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of OPGs within the optic pathway typically precludes complete resection or optimal radiation dosing, hence outcomes remain poor compared to many other low-grade gliomas. The aim of this systematic review was to formulate a comprehensive list of all current ongoing clinical trials that are specifically looking at clinical care of OPGs in order to identify trends in current research and provide an overview to guide future research efforts.

METHODS

This systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The Cochrane Controlled Register of Trials (CENTRAL) and ClinicalTrials.gov were searched. Inclusion and exclusion criteria were applied and final results were reviewed.

RESULTS

501 clinical trials were identified with the search strategy. All were screened and eligible studies extracted and reviewed. This yielded 36 ongoing clinical trials, 27 of which were pharmacological agents in phase I-III. The remaining trials were a mixture of biological agents, radiation optimisation, diagnostic imaging, surgical intervention, and a social function analysis.

CONCLUSION

OPG is a complex multifaceted disease, and advances in care require ongoing research efforts across a spectrum of different research fields. This review provides an update on the current state of research in OPG and summarises ongoing trials.

Long-term visual acuity in patients with optic pathway glioma treated during childhood with up-front BB-SFOP chemotherapy-Analysis of a French pediatric historical cohort

Background

Visual outcome is one of the main issues in the treatment of optic pathway glioma in childhood. Although the prognostic factors of low vision have been discussed extensively, no reliable indicators for visual loss exist. Therefore, we aimed to define initial and evolving factors associated with long-term vision loss.

Methods

We conducted a multicenter historical cohort study of children treated in France with up-front BB-SFOP chemotherapy between 1990 and 2004. Visual acuity performed at the long-term follow-up visit or within 6 months prior was analyzed. Logistic regression analysis was used to estimate the effects of clinical and radiological factors on long-term visual outcome.

Findings

Of the 180 patients in the cohort, long-term visual acuity data were available for 132 (73.3%) patients (median follow-up: 14.2 years; range: 6.1–25.6). At the last follow-up, 61/132 patients (46.2%) had impaired vision, and 35 of these patients (57.3%) were partially sighted or blind. Multivariate analysis showed that factors associated with a worse prognosis for long-term visual acuity were an age at diagnosis of < 1 year (OR 3.5 [95% CI: 1.1–11.2], p = 0.04), tumor extent (OR 4.7 [95% CI: 1.2–19.9], p = 0.03), intracranial hypertension requiring one or more surgical procedures (OR 5.6 [95% CI: 1.8–18.4], p = 0.003), and the need for additional treatment after initial BB-SFOP chemotherapy (OR 3.5 [95% CI: 1.1–11.9], p = 0.04). NF1 status did not appear as a prognostic factor, but in non-NF1 patients, a decrease in tumor volume with contrast enhancement after BB-SFOP chemotherapy was directly associated with a better visual prognosis (OR 0.8 [95% CI: 0.8–0.9], p = 0.04).

Interpretation

Our study confirms that a large proportion of children with optic pathway glioma have poor long-term outcomes of visual acuity. These data suggest new prognostic factors for visual acuity, but these results need to be confirmed further by large- and international-scale studies.

NEUROFIBROMATOSIS TYPE 1 AND OPTIC PATHWAY GLIOMA

PURPOSE

Evaluate the effectiveness of treatment of patients with optic pathway glioma.

MATERIALS AND METHODS

Comparison of literature research on neurofibromatosis and optic pathway glioma with a cohort of pediatric patients treated at the Childrens Ophthalmology Clinic of the University Hospital in Brno from January 2013 until June 2018.

DISCUSSION

The main challenge of this and other retrospective studies is variable intervals between ophthalmologic examinations. In some pediatric patients it is also difficult to objectively assess visual functions. The main risk factors are age at the time of treatment and tumor localization. Tumor progression itself does not always correlate with worse visual acuity outcomes, and it remains to be evaluated whether some patients would be better off without treatment. As of now, there are no clinical biomarkers able to predict impending visual acuity loss.

CONCLUSION

The cohort outcome agrees with literature. Chemotherapy remains a treatment of choice and its most likely outcome is visual acuity stabilization. In order to properly evaluate the treatments effectiveness, better collaboration between medical specialists and regular standardized ophthalmology examinations are required.

Neurofibromatosis Type 1: Review and Update on Emerging Therapies

Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder affecting 1 in 3000 births. This familial tumor predisposition syndrome is diagnosed clinically and affects the skin, bones, and nervous system. Malignant tumors can arise in childhood or adulthood and are the most common cause of mortality in this population. Early diagnosis and management led by a multidisciplinary team remains the standard of care, particularly in the management of optic pathway glioma. Emerging concepts in the genetic patterns of this condition have led to the introduction of new treatment modalities that target the mitogen-activated protein kinase and the mammalian target of rapamycin pathways. In this review, the role of the ophthalmologist and approach to screening for optic pathway glioma are outlined based on previous recommendations. Updates on choroidal involvement, as a diagnostic criterion, will also be discussed, further highlighting the pivotal role of the ophthalmologist in the diagnosis and management of this complex condition.

Cancer and Central Nervous System Tumor Surveillance in Pediatric Neurofibromatosis 1

Although the neurofibromatoses consist of at least three autosomal dominantly inherited disorders, neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis, NF1 represents a multisystem pleiotropic condition very different from the other two. NF1 is a genetic syndrome first manifesting in childhood; affecting multiple organs, childhood development, and neurocognitive status; and presenting the clinician with often complex management decisions that require a multidisciplinary approach. Molecular genetic testing (see article for detailed discussion) is recommended to confirm NF1, particularly in children fulfilling only pigmentary features of the diagnostic criteria. Although cancer risk is not the major issue facing an individual with NF1 during childhood, the condition causes significantly increased malignancy risks compared with the general population. Specifically, NF1 is associated with highly elevated risks of juvenile myelomonocytic leukemia, rhabdomyosarcoma, and malignant peripheral nerve sheath tumor as well as substantial risks of noninvasive pilocytic astrocytoma, particularly optic pathway glioma (OPG), which represent a major management issue. Until 8 years of age, clinical assessment for OPG is advised every 6 to 12 months, but routine MRI assessment is not currently advised in asymptomatic individuals with NF1 and no signs of clinical visual pathway disturbance. Routine surveillance for other malignancies is not recommended, but clinicians and parents should be aware of the small risks (<1%) of certain specific individual malignancies (e.g., rhabdomyosarcoma). Tumors do contribute to both morbidity and mortality, especially later in life. A single whole-body MRI should be considered at transition to adulthood to assist in determining approaches to long-term follow-up. Clin Cancer Res; 23(12); e46-e53. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Optic Gliomas in Neurofibromatosis Type 1

PURPOSE

To examine the incidence, presentation, and outcome of optic gliomas in children with neurofibromatosis type 1 (NF1) in Southern California Kaiser Permanente.

METHODS

The authors queried the Southern California Kaiser Permanente electronic medical record database to find patients diagnosed as having NF1. Genetics, ophthalmology, and imaging medical records of patients with optic glioma were reviewed.

RESULTS

A total of 708 patients younger than 21 years had a diagnosis of NF1 in Southern California Kaiser Permanente and 30 (4.2%) had a diagnosis of optic glioma. The average age of diagnosis was 5 years, with a range of 18 months to 12 years. Half (15 of 30) of the patients diagnosed as having optic glioma presented with symptoms (eg, vision loss, proptosis, and precocious puberty). Eight of 15 of the symptomatic patients were treated with surgery and/or chemotherapy. Symptomatic children were diagnosed later than those diagnosed through routine screening (5.7 vs 3.9 years old). The oldest child presented with symptoms at age 12 years. One asymptomatic patient had prophylactic chemotherapy. Sixty-three percent (19 of 30) of the gliomas were bilateral, 23% (7 of 30) were right-sided, and 13% (4 of 30) were left-sided. Fifty-three percent (17 of 30) of the gliomas involved the optic chiasm.

CONCLUSIONS

Screening practices for optic glioma are inconsistent. Most children with NF1 at risk for optic glioma do not have even one visit with an ophthalmologist. Children with NF1 can develop asymptomatic optic glioma as early as age 1 year. Annual ophthalmologic examination and screening for precocious puberty in children with NF1 is important for early diagnosis of optic gliomas and may reduce morbidity. [J Pediatr Ophthalmol Strabismus. 2016;53(6):334-338.].

Optic Pathway Glioma and Cerebral Focal Abnormal Signal Intensity in Patients with Neurofibromatosis Type 1: Characteristics, Treatment Choices and Follow-up in 134 Affected Individuals and a Brief Review of the Literature

Optic pathway glioma (OPG) is a rare neoplasm and a defining feature of neurofibromatosis type 1 (NF1), a tumor suppressor genetic disorder. OPG predominantly arises during childhood. In contrast to sporadic OPG, this neoplasm frequently appears to show a more favorable course. Outcome appears to depend on localization of tumor; however, the correlation of imaging findings and visual acuity is in general low. Treatment for symptomatic OPG is not well standardized. Furthermore, determination of visual acuity as the most important parameter of follow-up control is often difficult to determine, particularly in children. Focal abnormal signal intensity (FASI) is a characteristic finding on magnetic resonance imaging (MRI) of NF1 patients. The aim of this study was to evaluate clinical and imaging findings of NF1 patients affected with OPG.

PATIENTS AND METHODS

Data of 925 NF1 patients with appropriate MRI cranial sectional images (N=1,948) were evaluated. A further 50 patients with cranial computed tomograms were included in the study. We compared imaging and clinical findings with respect to localization of OPG. Furthermore, we compared follow-up in treated individuals to those who were only regularly re-examined. The presence of FASI on MRI was determined and correlated to the occurrence of OPG. Dodge classification was applied to categorize OPG location.

RESULTS

OPG was diagnosed in 134 patients. The mean age of patients with symptomatic OPG was 7.6 years (n=57, 42.5%) and 11.6 years (n=77, 57.5%) in asymptomatic patients. The female to male ratio was about 1.1:1. In 48 symptomatic patients, the findings of initial ophthalmological investigations were available. In symptomatic patients, reduced visual acuity was the predominant finding. Strabismus (25%), exophthalmos (22.9%) and amblyopia (20.8%) were most frequently noticed, followed by endrocrinological abnormalities (14.6%). However, these findings did not differ between patients who were treated or who were subjected to a 'wait-and-see' policy. We could not verify an effect of therapy on vision in patients treated for OPG compared to symptomatic patients without treatment. OPG affecting the total optic pathway was more frequently diagnosed in symptomatic patients. FASI did not correlate with functional OPG status.

CONCLUSION

OPG in NF1 is symptomatic in slightly less than 50% of affected individuals. This neurological finding may show a wide range of symptoms. At present, no established treatment protocol emerges from the history of the patients of this study and also from the literature. Although the onset of symptomatic OPG is strongly associated with early childhood, late onset of symptomatic OPG is a feature of adult NF1. Research for association of FASI to neurological findings in these patients should be based on other issues than association with OPG.

Optic pathway gliomas: a review

Optic pathway gliomas account for 3-5% of all pediatric CNS tumors and represent the most common intrinsic optic nerve tumors. These tumors occur preferentially during the first decade of life and are particularly frequent in children with neurofibromatosis type 1. Although optic pathway gliomas are low-grade tumors, their behavior can be aggressive, and their management is often challenging. Their management includes observation, surgery, chemotherapy and radiation. The role of each modality is discussed as well as current and future developments in treatment, in particular targeted therapies that are currently being investigated.

Natural history and clinical management of optic pathway glioma

Twenty-five consecutive unselected patients with optic pathway glioma (OPG) were primarily observed and treated if progression was evident. Diagnosis was based on MRI. The natural history of the OPG disease was more indolent in 12 patients with neurofibromatosis 1 (NF1) than in the others, and regressions were commonly observed. Thirteen non-NF1 patients had larger rumours at diagnosis and more progressions. There were five intra-orbital optic nerve tumours (one with progression), 19 chiasmatic tumours (12 with progression) and one diffuse tumour. OPG emerges before the age of 7 years in NF1 patients, and in non-NF1 patients also in older patients including adults. Progressive intra-orbital OPGs are best treated by surgical resection. Progressive chiasmatic tumours are best treated by radiotherapy and respond well by marked regression. Exceptionally, exophytic chiasmatic tumours may be treated by chiasm preserving surgery.

Visual outcome of a cohort of children with neurofibromatosis type 1 and optic pathway glioma followed by a pediatric neuro-oncology program

We evaluated the visual outcome of a cohort of children with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG) treated according to standardized therapeutic guidelines. The study population consisted of all consecutive patients with NF1 and OPG referred to a specialized pediatric neuro-oncology program between 1994 and 2004. Treatment was instituted only in cases of progressive disease or clinical deterioration. Treatment modalities were chemotherapy (based on vincristine/carboplatin) for children younger than 5 years and radiotherapy for all others. Ten boys and 10 girls (seven with a positive family history) entered the trial (median age at diagnosis of OPG, 29 months). At a median follow-up time of 78 months, seven patients had been treated with chemotherapy only, four with radiotherapy, and four with chemotherapy plus radiotherapy. Five patients were observed only. Currently, 18 are alive and two have died. Eight patients were treated for progressive visual loss in the face of stable disease, five for tumor volume increase without visual deterioration, and two for symptomatic tumor volume increase. At referral, six children had a visual acuity (VA) of < 30% in both eyes; eight children had 100% VA bilaterally. At referral, the visual field (VF) could be assessed in three children: One had VF loss in both eyes, one had VF loss in one eye, and one had normal VF. At last follow-up, eight children had VA < 20% in both eyes; only two children had 100% VA in both eyes. Among 11 children who had some visual function, three had VF loss in one eye and three in both eyes, and five had an intact VF. Contrast and color sensitivity were abnormal in seven and six patients, respectively. Thirteen children fell into the WHO hypovision category. In summary, among the 15 children treated, one had a definitive and two a mild improvement in VA. In conclusion, the visual outcome of this selected cohort of NF1 patients with OPG is unsatisfactory. A critical reappraisal of the therapeutic strategy adopted is needed.

Optic glioma warranting treatment in children

PURPOSE

To describe cases of optic pathway glioma (OPG) warranting treatment in children.

METHODS

This is a retrospective review of pediatric patients treated for OPG. The clinical data and imaging studies were obtained from the medical records and radiology files of patients seen at the Pediatric Neuro-Ophthalmology Clinic at the University of Illinois, Chicago and the private office of the author (LMK).

RESULTS

A total of seven cases with an age range of 3-48 months at presentation were reviewed. Three of the patients were also ultimately diagnosed with neurofibromatosis type 1. Presenting symptoms included proptosis, decreased vision, gaze deficit, and nystagmus. Four patients underwent biopsies that confirmed OPG. Six of the patients were treated with intravenous chemotherapy, with three patients requiring a second chemotherapy cycle. One patient was successfully treated with an en-bloc optic nerve excision. Two patients underwent unilateral enucleation owing to globe complications.

CONCLUSION

Although benign tumours, OPG can behave very aggressively in young children. Both chemotherapy and en-bloc excision can be employed for treatment.

Optic pathway gliomas in neurofibromatosis-1: controversies and recommendations

Optic pathway glioma (OPG), seen in 15% to 20% of individuals with neurofibromatosis type 1 (NF1), account for significant morbidity in young children with NF1. Overwhelmingly a tumor of children younger than 7 years, OPG may present in individuals with NF1 at any age. Although many OPG may remain indolent and never cause signs or symptoms, others lead to vision loss, proptosis, or precocious puberty. Because the natural history and treatment of NF1-associated OPG is different from that of sporadic OPG in individuals without NF1, a task force composed of basic scientists and clinical researchers was assembled in 1997 to propose a set of guidelines for the diagnosis and management of NF1-associated OPG. This new review highlights advances in our understanding of the pathophysiology and clinical behavior of these tumors made over the last 10 years. Controversies in both the diagnosis and management of these tumors are examined. Finally, specific evidence-based recommendations are proposed for clinicians caring for children with NF1.

Assessment of Progression and Treatment Response of Optic Pathway Glioma with Positron Emission Tomography using α-[11C]Methyl-l-Tryptophan

PURPOSE

To report the utility of positron emission tomography (PET) with alpha-[(11)C]methyl-L-tryptophan (AMT) for monitoring progression and response to treatment of an isolated optic pathway glioma (OPG) in a 16-year-old girl.

PROCEDURES

Positron emission tomography scanning of the brain was performed 20 minutes after intravenous administration of AMT. The AMT-PET images were reconstructed and examined for tumor uptake of the tracer in correlation with coregistered magnetic resonance images.

RESULTS

The PET scan demonstrated increased uptake of AMT by OPG in a clinically symptomatic child whose magnetic resonance imaging (MRI) was inconclusive for morphological changes of the tumor. The tracer uptake was dramatically decreased on the images obtained after chemotherapy. Subsequently, AMT-PET revealed a new tumor lesion of increased AMT uptake when the patient developed vision problems and MRI showed no significant interval morphological changes. Significant vision improvement was observed after external beam radiotherapy for the newly identified tumor lesion.

CONCLUSIONS

Positron emission tomography with alpha-[(11)C]methyl-L-tryptophan may be useful for monitoring progression and response to treatment of OPGs, which needs to be further investigated in a prospective study of more patients, including those with neurofibromatosis.

Orbital optic nerve gliomas in children with neurofibromatosis type 1

PURPOSE

To describe the clinical course and treatment of symptomatic orbital optic nerve gliomas in children with neurofibromatosis type-1 (NF-1).

METHODS

A retrospective review of the records of patients with NF-1 and symptomatic orbital optic nerve gliomas seen in a large multidisciplinary NF-1 clinic of a tertiary care children's hospital. The main outcome measures included presenting symptoms and signs, ophthalmologic examination at diagnosis, the presence of progressive disease following diagnosis, type of therapy, and the reasons therapy was instituted.

RESULTS

Twelve patients with symptomatic orbital optic nerve gliomas, all of which led to proptosis (eight girls, four boys), were identified. The mean age of diagnosis of NF-1 was 20 months; the mean age of diagnosis of the orbital optic nerve glioma was 26 months. At the time of diagnosis of the tumor, 10 of 12 patients (83%) had decreased visual acuity in the affected eye. Three patients underwent optic nerve resection; eight received chemotherapy, and one was observed without therapy. Of the eight children who received chemotherapy, progressive disease prior to treatment could be documented in only three; none of these eight children had a reproducible improvement in vision following chemotherapy. There was no demonstrable improvement in vision in any treated patient with NF-1-associated orbital optic nerve gliomas.

CONCLUSIONS

Although not definitively proven, our data and previous studies suggest that NF-1-associated orbital optic nerve gliomas should not be treated unless there is clear evidence of either ophthalmologic or radiographic progression. Surgical excision of tumors which have led to proptotic eyes without functional vision should be reserved for cosmetic purposes or to treat complications of exposed globes.

Management of child optic pathway gliomas: new therapeutical option

OBJECTIVE

To present our experience in the treatment of child optic pathway gliomas in the last 25 years.

MATERIAL AND METHODS

Seventeen children under 10 years of age have been analyzed and assessed from clinic, ophthalmologic, endocrinologic, neurological, neuropathologic, and imaginologic points of view.

RESULTS

Predominance of female patients, 10 girls and 7 boys between 6 and 122 months old; mean age was 3 years and 8 months. The most frequent symptoms have been ophthalmologic and visual alterations in all 17 patients, endocrine alterations in 10, and neurological signs in 6. One of the patients presented neurofibromatosis type 1 (NF1), another patient had Down syndrome. Diagnosed using computed tomography or/and magnetic resonance imaging, histological studies showed pilocytic astrocytomas in 13 cases and a fibrillary astrocytoma grade II in 1 case. There were three patients without histological diagnosis; one of them had NF1. The treatment consisted of surgery, external beam radiotherapy, chemotherapy, and brachytherapy with iodine 125, separately or combined. Five patients died; the causes were secondary tumors in two children, tumor recurrence in one, sepsis secondary to respiratory and urinary tract infections in the child with Down syndrome, and finally, hydrocephaly due to hyperproteinorachia of tumor origin in one. Average survival was 89 months.

CONCLUSION

Chemotherapy and brachytherapy are therapeutic methods to be considered, especially in children under 5. Marsupialization of the residual cyst into the ventricular system postradio or oncolytic treatment through endoscopic or stereotactic techniques is useful in the treatment of endocranial hypertension and/or hypothalamic compression in these patients.

Prognostic factors for progression of childhood optic pathway glioma: a systematic review

A systematic literature review was carried out to evaluate best existing evidence on prognostic factors for progression of childhood optic pathway glioma. Databases were searched for relevant articles and articles selected independently by two authors. Information about study design, population, treatment, outcome and prognostic analysis were abstracted and the quality of each article was assessed. A total of 23 articles met the inclusion criteria. Many studies had important methodological limitations, regarding external and internal validity. Eleven studies evaluated possible prognostic factors in a multivariate analysis. Three high-quality studies indicated age<1 year as an independent prognostic factor for a worse progression-free survival. Three studies with multivariate analysis, including one high-quality study, found that children with neurofibromatosis type 1 (NF-1) have a better progression-free survival than those without NF-1. Two studies with multivariate analysis found tumour site to be a prognostic factor, both with some methodological limitations. In conclusion, this systematic review demonstrates that only a few of the prognostic factors proposed have been proven to be clinically relevant. Age<1 year is a clear and independent prognostic factor for progression-free survival. Other prognostic factors, such as NF-1, tumour site and others, are suggested, but are still without solid evidence and need further high-quality studies to be clearly proven.

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.

Late-onset optic pathway tumors in children with neurofibromatosis 1

Identification of new optic pathway tumors (OPTs) and progression of pre-existing OPTs in children with neurofibromatosis 1 (NF1) have been reported infrequently after age 6. The authors present eight children with NF1 (mean age 12.2 years) seen in three NF1 centers who had either late-onset (four of eight) or late-progressive (seven of eight) OPT. Continued monitoring of individuals with NF1 into adulthood for the development of OPTs and for progression of known OPTs is warranted.

Synchronous optic and pineal pilocytic astrocytomas in a paediatric patient with neurofibromatosis type 1

A 12-year-old girl with neurofibromatosis type 1 presented with headache, visual acuity and visual field disturbance. Computed tomography and magnetic resonance imaging revealed an enhanced solid mass involving her right optic nerve and optic chiasm, and a cystic lesion in the pineal region that had resulted in obstructive hydrocephalus. An open biopsy of the right optic nerve tumour was performed, and it was histologically identified as a pilocytic astrocytoma. Local irradiation of 50 Gy to the optic pathway tumour was performed, and the tumour has remained stable for more than 29 months. On the contrary, the pineal cystic mass that was also histologically identified as a pilocytic astrocytoma showed marked enlargement within 5 months after a subtotal resection. Chemotherapy with cisplatin and vincristine was performed after a second surgery, and the pineal tumour has not re-grown in 18 months. To our knowledge, this is the first case report to describe synchronous optic and pineal pilocytic astrocytomas associated with neurofibromatosis type 1.

Recent advances in optic nerve glioma with a focus on the young patient

PURPOSE OF REVIEW

Optic tract low-grade gliomas are one of the commonest category of neoplasm presenting in childhood and early adolescence. Recent reports covering their aetiology, imaging techniques, the application of novel radiotherapy techniques and chemotherapy are reported.

RECENT FINDINGS

These tumours are increasingly being seen as markers of enhanced risk in patients and their families for the subsequent development of central nervous system tumours. Modern imaging techniques are being explored for their diagnostic sensitivity and specificity as well as their ability to describe, with greater precision, anatomical boundaries in order to minimize, through conformal techniques, radiation doses to organs at risk within the brain. Increasing numbers of trials of chemotherapy agents are demonstrating efficacy in this tumour category.

SUMMARY

Visual pathway low-grade astrocytomas of childhood are the subject of diverse research into diagnostic aetiological and treatment aspects aimed at tailoring diagnostic and treatment procedures more precisely to the needs of the young patient for this tumour type.

Optic radiation involvement in optic pathway gliomas in neurofibromatosis

PURPOSE

Optic pathway gliomas (pilocytic astrocytomas) in neurofibromatosis type 1 (NF-1) typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is rare.

DESIGN

This paper describes seven patients with NF-1 with gliomas involving the pregeniculate optic pathway in addition to the optic radiations.

METHODS

A retrospective database review was made of all patients with NF-1 and optic pathway gliomas seen by one of the authors (G.T.L.) at the Children's Hospital of Philadelphia from July 1993 to October 2001. Patients with involvement of pregeniculate optic pathway and the optic radiations were identified. From November 2001 to February 2003, patients were sought prospectively. Cases were also identified from the practice of another author (M.C.B.) at Arkansas Children's Hospital.

RESULTS

Four patients from Children's Hospital of Philadelphia (three of 83 total NF-1/optic pathway gliomas from July 1993 to October 2001 and one prospectively) and three from Arkansas Children's Hospital were identified. Two had expanding mass lesions within the white matter of the temporal or parietal lobes, which were histopathologically demonstrated to be pilocytic astrocytomas. The other five had radiographic involvement of the optic radiations but did not undergo biopsy. In three of the cases the vision was 20/200 or worse in each eye.

CONCLUSIONS

Optic pathway gliomas in NF-1 may rarely involve the optic radiations. Optic radiation involvement may signal a more aggressive optic pathway glioma in patients with neurofibromatosis-1.

Neurofibromatosis type 1 and optic pathway gliomas Follow-up of 54 patients

OBJECTIVE

To describe the natural history of optic pathway gliomas (OPGs) in patients with neurofibromatosis type 1 (NF1), and to evaluate the current recommended guidelines for monitoring and follow-up of OPGs in this population.

DESIGN

Retrospective case series.

PARTICIPANTS

Patients with OPGs and NF1 seen in the neurofibromatosis clinic at the Children's Hospital at Westmead in Sydney, Australia.

METHODS

Patients with definite NF1 and confirmed OPGs were identified and their medical records searched to obtain data on demographics, details of the OPG diagnosis, and serial ophthalmic examination findings. Patients were stratified into groups according to age and mode of presentation.

MAIN OUTCOME MEASURES

Visual acuity was recorded for each eye and grouped into mild (Snellen equivalent > or = 6/12), moderate (Snellen equivalent = 6/15-6/60), and severe (Snellen equivalent < 6/60) visual impairment at time of diagnosis, during follow-up, and at the most recent examination.

RESULTS

Data were collected on 54 patients, the majority of whom (78%) were seen from 1990 to 2002, with an average follow-up of 8.6 years. The mean age at the time of OPG diagnosis was 5.2 years, with 32 patients having symptoms or signs at the time of diagnosis. Seventeen patients were diagnosed after the age of 6 years (range, 7-15). Twenty-two patients had tumor progression within 1 year of diagnosis, and a further 6 patients showed progression after 1 year. Most patients' conditions were managed conservatively (68.5%). At follow-up, 17 patients (31.5%) had severe visual impairment (<6/60 Snellen equivalent) in their worse eye, and 16.7% had bilateral moderate/severe visual impairment.

CONCLUSIONS

Contrary to some previous reports, our results show that OPGs in patients with NF1 often present in older children and may progress some time after diagnosis. Given the potential for serious visual consequences, these findings indicate a need for regular ophthalmological monitoring of this population for a long duration.

Optic gliomas: a retrospective analysis of 50 cases

PURPOSE

Gliomas of the optic pathways are rare childhood central nervous system tumors. The treatment approach is controversial because of its rarity and the slow and unpredictable growth rates of these lesions.

METHODS AND MATERIALS

We reviewed 50 patients with the diagnosis of optic pathway low-grade gliomas treated between January 1980 and December 1995 at King Faisal Specialist Hospital and Research Center, Saudi Arabia. Thirty-five patients presented with chiasmatic/hypothalamic (posterior tumors), and 15 with optic nerve gliomas with or without chiasmal involvement (anterior tumors). Evidence of neurofibromatosis was present in 18 patients. Twenty-nine patients underwent surgery (total or partial resection), and 12 of these received postoperative radiotherapy (RT). Sixteen patients were treated with primary RT. The radiation dose varied between 42 and 54 Gy (median dose 50).

RESULTS

The overall actuarial survival rate was 87.5% at 5 years and 75% at 10 years, and the corresponding progression-free survival (PFS) rates were 69% and 62%. Patients with anterior tumors fared better than those with posterior tumors, with a 10-year PFS rate of 72% and 58%, respectively; the difference, however, was not statistically significant (p = 0.58). A PFS advantage was found in favor of patients with posterior tumors treated with RT (primary or postoperative) compared with no RT, with 5-year PFS rates of 68% vs. 42% (p = 0.03). This, however, did not translate into a survival advantage because of the success of salvage treatment.

CONCLUSION

In multivariate analysis, age (<3 vs. >3 years) emerged as the only significant determinant for PFS with patients <3 years old faring worse (p = 0.03). Neurologic and endocrine dysfunction are significant problems that need to be addressed.

Neurofibromin in the brain

Neurofibromatosis 1 is one of the most common autosomal dominant disorders affecting the nervous system. Individuals with neurofibromatosis 1 present with abnormalities of both astrocytes and neurons that result from reduced or absent expression of the NF1 gene product neurofibromin. Impaired neurofibromin function in these nervous system cells contributes to the development of astrocytomas, learning disabilities, and radiographic abnormalities of the brain. With the identification of NF1, significant advances have begun to unlock some of the mysteries that surround the molecular pathogenesis of neurofibromatosis 1-associated brain abnormalities. With continued advances in our basic understanding of NF1 function, future targeted therapies for neurofibromatosis 1-associated central nervous system abnormalities can be developed.

Intracranial neoplasms in children with neurofibromatosis 1

Neurofibromatosis 1 is associated with an increased risk for the development of benign and malignant tumors involving neural and non-neural tissues. Children as well as adults with neurofibromatosis 1 are affected. Central nervous system neoplasms represent a significant portion of these malignancies and appear primarily in children less than 10 years of age. Optic pathway gliomas and brainstem gliomas are the most common intracranial neoplasms found in neurofibromatosis 1, although there also is an increased incidence of other brain tumors in this population. The majority of these intracranial neoplasms are benign pilocytic astrocytomas, which may behave in a less aggressive manner than histologically identical tumors in non-neurofibromatosis 1 patients. Owing to the indolent nature of these tumors, conservative management with close follow-up is recommended. When intervention is required, conventional treatment with surgery, radiation, or chemotherapy has been used with variable results. The current challenge lies in understanding the pathogenesis of gliomas in neurofibromatosis 1, which may lead to the development of biologically directed therapies with less associated morbidity and mortality for neurofibromatosis 1 as well as non-neurofibromatosis 1 children.

Neurofibromatosis 1

Neurofibromatosis 1 is one of the most common genetic conditions affecting the nervous system. Individuals with NF1 are predisposed to the development of peripheral nerve sheath tumors (neurofibromas and MPNSTs), astrocytomas (optic pathway gliomas), learning disabilities, seizures, strokes, macrocephaly, and vascular abnormalities. The NF1 tumor suppressor gene encodes a large protein (neurofibromin) that functions primarily as a RAS negative regulator, suggesting that targeted therapy for NF1 might derive from inhibition of the RAS signaling pathway.

Neurofibromatosis type 1 and sporadic optic gliomas

AIMS

To compare the natural history of sporadic optic glioma with those associated with neurofibromatosis type 1 (NF1).

METHODS

Optic glioma cases were identified using both the Manchester Children's Tumour Registry (CTR) and the North West Regional NF1 Database (NF1DB), with detailed information on natural history available from the former (in 34 of 36 cases identified).

RESULTS

A total of 52 cases over a period of 41 years were identified. From the 34 whose natural history was known, almost all (n = 31) were symptomatic, with mean ages of presentation of 4.5 and 5.1 years for NF1 and sporadic cases respectively. The majority (n = 22) presented with visual impairment, seven of whom were blind in at least one eye. Sporadic cases were over twice as likely as NF1 to have visual impairment. Recurrence occurred in 12 patients. Fewer NF1 patients died as a direct result of their optic glioma, but overall mortality and 5 and 10 year survival rates between the two groups were similar. All five primary (non-metastatic) second central nervous system (CNS) tumours occurred in NF1 cases, two of these following radiotherapy.

CONCLUSIONS

Symptomatic sporadic optic gliomas presented with impaired vision more frequently and were more aggressive than NF1 optic gliomas. Only optic glioma cases with NF1 were at risk of developing a second CNS tumour. Aggressive treatment of sporadic optic gliomas and early surveillance of NF1 optic gliomas may be required. The use of radiotherapy in these children requires further clarification.

Growth hormone and neurofibromatosis

Data collected from 102 neurofibromatosis (NF) children with growth hormone (GH) deficiency (GHD) who were receiving GH replacement therapy were reviewed to assess the efficacy and safety of GH therapy in this condition. GH was administered at a mean dose of 0. 18 mg/kg/week. During the 1st year the median height velocity increased significantly from 4.2 cm/year before treatment to 7.1 cm/year, and the median height standard deviation score increased from -2.4 to -1.9. The response to therapy, however, was not as good as that observed in patients with idiopathic GHD. GH therapy did not influence the progression of any of the features of NF, including intracranial tumours, and was not associated with an excess of other adverse events. We conclude that GH treatment of NF patients with GHD is beneficial in terms of improved growth rate and is well tolerated.

When do children with optic pathway tumours need treatment? An oncological perspective in 106 patients treated in a single centre

Progression patterns of optic pathway tumours (OPT) need to be precisely defined for treatment planning. In patients with neurofibromatosis type 1 (NF1), this disease is usually indolent and the available literature rarely reports progression after the age of 6 years. In patients without NF1, the disease course seems to be less favourable. We reviewed the clinical and radiological files of 106 children referred to our institution for the treatment of a symptomatic OPT since 1980. NF1 was present in 51 of them. Progression patterns in children with NF1 differed markedly from those in the other patients. A total of 83 children had tumour extension beyond the chiasm (Dodge type III). Children with NF1 had progressive tumours later during follow-up (47% after the age of 6 years), had more often proptosis and infiltrating tumours but less frequently nystagmus or increased intracranial pressure. 32 children were not treated at diagnosis because they had only mild symptoms related to the OPT. In these patients, progression occurred more often in children without than with NF1 (12/12 versus 12/20 respectively, P = 0.04). A high number of patients needed treatment for progression or severe symptoms after 6 years of age. Of the patients, 33% needed treatment for progression or severe symptoms after 6 years of age.

CONCLUSION

Progression patterns of optic pathway tumours in children with neurofibromatosis type 1 differ markedly from those in other patients. This study emphasises the need for prolonged follow-up of children with optic pathway tumours, especially in neurofibromatosis type 1.

[Current concepts on the treatment of glioma of optic nerve and chiasm]

Based on the data from literature, the authors present current concepts on the treatment of glioma of the optic nerve and chiasm. The influence of location and biological behaviour of these tumours on making decision about the most appropriate treatment regarding the results and minimum of side-effects, is emphasized.