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.

Grating visual acuity impairment assessed by sweep visually evoked potentials in children with optic pathway tumors unable to perform optotype acuity tests / Deficiência na acuidade visual de grades avaliada pelos potenciais visuais evocados de varredura em crianças com tumores da via óptica incapazes de informar a acuidade de optotipos

ABSTRACT Purpose: To determine visual impairment due to optic pathway tumors in children unable to perform recognition acuity tests. Methods: Grating visual acuity scores, in logMAR, were obtained by sweep visually evoked potentials (SVEP) in children with optic pathway tumors. The binocular grating visual acuity deficit was calculated by comparison with age-based norms and then assigned to categories of visual impairment as mild (from 0.10 to 0.39 logMAR), moderate (from 0.40 to 0.79 logMAR), or severe (≥0.80 logMAR). Interocular differences were calculated by subtraction and considered increased if >0.10 logMAR. Results: The participants were 25 children (13 boys; mean ± SD age, 35.1 ± 25.9 months; median age, 32.0 months) with optic pathway tumors (24 gliomas and 1 embryonal tumor), mostly located at the hypothalamic-chiasmatic transition (n=21; 84.0%) with visual abnormalities reported by parents (n=17; 68.0%). The mean grating acuity deficit was 0.60 ± 0.36 logMAR (median, 0.56 logMAR). Visual impairment was detected in all cases and was classified as mild in 10 (40.0%), moderate in 8 (32.0%), and severe in 7 (28.0%) children, along with increased interocular differences (>0.1 logMAR) (n=16; 64.0%). The remarkable ophthalmological abnormalities were nystagmus (n=17; 68.0%), optic disc cupping and/or pallor (n=13; 52.0%), strabismus (n=12; 48.0%), and poor visual behavior (n=9; 36.0%). Conclusion: In children with optic pathway tumors who were unable to perform recognition acuity tests, it was possible to quantify visual impairment by sweep-visually evoked potentials and to evaluate interocular differences in acuity. The severity of age-based grating visual acuity deficit and interocular differences was in accordance with ophthalmological abnormalities and neuroimaging results. Grating visual acuity deficit is useful for characterizing visual status in children with optic pathway tumors and for supporting neuro-oncologic management.(AU)

RESUMO Objetivo: Determinar o grau de deficiência visual em crianças com tumores da via óptica incapazes de informar a acuidade visual de reconhecimento. Método: A acuidade visual de grades, em logMAR, foi estimada por potenciais visuais evocados de varredura em crianças com tumores das vias ópticas. O déficit da acuidade visual de grades binocular foi calculado em relação ao valor mediano normativo esperado para a idade e a deficiência visual, classificada como leve (0,10 a 0,39 logMAR), moderada (0,40 a 0,79 logMAR) ou grave (≥0,80 logMAR). Diferenças inter-oculares foram calculadas por subtração e consideradas aumentadas se >0,10 logMAR. Resultados: Foram avaliadas 25 crianças (13 meninos; média de idade ± DP=35,1± 25,9 meses; mediana=32,0 meses) com tumores da via óptica (24 gliomas e 1 tumor embrionário) localizados particularmente na transição hipotalâmico-quiasmática (n=21; 84,0%) e com anormalidades visuais detectadas pelos pais (n=17; 68,0%). A média do déficit da acuidade de grades foi 0,60 ± 0,36 logMAR (mediana=0,56 logMAR). Observou-se deficiência visual leve em 10 (40,0%), moderada em 8 (32,0%) e grave em 7 (28,0%), além de aumento da diferença interocular da acuidade visual (n=16; 64,0%). As principais alterações oftalmológicas encontradas foram: nistagmo (n=17; 68,0%), aumento da escavação do disco óptico e/ou palidez (n=13; 52,0%), estrabismo (n=12; 48,0%) e comportamento visual pobre (n=9; 36,0%). Conclusão: Em crianças com tumor da via óptica e incapazes de responder aos testes de acuidade visual de reconhecimento, foi possível quantificar deficiência visual por meio dos potenciais visuais evocados de varredura e avaliar a diferença interocular da acuidade visual de grades. A gravidade do déficit da acuidade visual de grades relacionado à idade e a diferença interocular da acuidade visual de grades foram congruentes com alterações oftalmológicas e neuroimagem. O déficit da acuidade visual de grades foi útil à caracterização do estado visual em crianças com tumores da via óptica e ao embasamento da assistência neuro-oncológica.(AU)

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

OBJECT: Optic pathway tumors (OPT) represent a challenge for pediatric neurosurgeons. Role of surgery is debated due to the high risk of iatrogenic damage, and in lasts decades it lost its importance in favor of chemotherapy. However, in some cases surgery is necessary to make biomolecular and histological diagnosis, to manage intracranial hypertension (IH) and to cooperate with medical therapies in controlling tumor relapse. With the aim to standardize selection of surgical OPT cases, we propose a simple, practical and reproducible classification. METHODS: We retrospectively analyzed data of 38 patients with OPT treated at our institution (1990-2018). After careful analysis of MRI images, we describe a new classification system. Group 1: lesion limited to one or both optic nerve(s). Group 2: chiasmatic lesions extending minimally to hypothalamus. Group 3: hypothalamo-chiasmatic exophitic lesions invading the third ventricle; they can be further divided on the base of concomitant hydrocephalus. Group 4: hypothalamo-chiasmatic lesions extending widely in lateral direction, toward the temporal or the frontal lobes. Patients' data and adopted treatment are reported and analyzed, also depending on this classification. RESULTS: Twenty children were operated on for treatment of OPT during the study period. Permanent clinical impairment was noted in 5 (25%) of operated patients, while visual improvement was noted in 1 patient. OS rate was 100% at 5 years, with a median follow up of 9 years (ranging from 2 to 23). Prevalence of intracranial hypertension and proportion of first-line surgical treatment decision were significantly higher in groups 3-4 compared to groups 1-2 (P<0.001 for both tests). CONCLUSION: Surgery can offer a valuable therapeutic complement for OPT without major risk of iatrogenic damage. Surgery is indispensable in cases presenting with IH, as in groups 3 and 4 lesions. Eligibility of patients to surgery can be based on this new classification system.

"They've got a lot of needs and I don't think they're being met fully": A qualitative study of the multi-professional team approach to the management of children with optic pathway gliomas.

BACKGROUND: Optic pathway gliomas (OPGs) are low-grade tumours of the visual pathway. Although survival rates are high, there is considerable morbidity and hence treatment focuses on preservation of vison and quality of life. The multiple, complex issues faced by these patients are often confounded by a concurrent diagnosis of neurofibromatosis type-1 (NF1). As there is a paucity of literature addressing the current practices of the multi-professional team (MPT) caring for children diagnosed with an OPG, individual professional experiences often guide the MPT's approach to the care of these children and their families. AIMS: This study aimed to gain views on the management of children with OPGs, from MPT members involved in their care, in order to inform recommendations on how to improve the service offered to these children and their families. METHODS: A qualitative design collected experiential data from MPT members via semi-structured interviews. MPT focus groups were used to validate the data. RESULTS: Data collected from 20 MPT members resulted in the overarching themes of Issues Faced by the Patient and Family and Challenges to the Holistic Care of the Patient. Four recommendations are suggested, namely (1) the production of an MPT training resource, (2) improved visual team links, (3) an OPG patient passport and (4) a joint NF1-OPG clinic. CONCLUSION: There are many challenges to MPT members providing holistic care to patients with OPGs. As no OPG clinical practice guidelines currently exist, it is suggested that the above recommendations be piloted with evaluation to validate their use.

Validation of an automated tractography method for the optic radiations as a biomarker of visual acuity in neurofibromatosis-associated optic pathway glioma.

INTRODUCTION: Fractional anisotropy (FA) of the optic radiations has been associated with vision deficit in multiple intrinsic brain pathologies including NF1 associated optic pathway glioma, but hand-drawn regions of interest used in previous tractography methods limit consistency of this potential biomarker. We created an automated method to identify white matter tracts in the optic radiations and compared this method to previously reported hand-drawn tractography. METHOD: Automated tractography of the optic radiation using probabilistic streamline fiber tracking between the lateral geniculate nucleus of the thalamus and the occipital cortex was compared to the hand-drawn method between regions of interest posterior to Meyer's loop and anterior to tract branching near the calcarine cortex. Reliability was assessed by two independent raters in a sample of 20 healthy child controls. Among 50 children with NF1-associated optic pathway glioma, the association of FA and visual acuity deficit was compared for both tractography methods. RESULTS: Hand-drawn tractography methods required 2.6±0.9min/participant; automated methods were performed in <1min of operator time for all participants. Cronbach's alpha was 0.83 between two independent raters for FA in hand-drawn tractography, but repeated automated tractography resulted in identical FA values (Cronbach's alpha=1). On univariate and multivariate analyses, FA was similarly associated with visual acuity loss using both methods. Receiver operator characteristic curves of both multivariate models demonstrated that both automated and hand-drawn tractography methods were equally able to distinguish normal from abnormal visual acuity. CONCLUSION: Automated tractography of the optic radiations offers a fast, reliable and consistent method of tract identification that is not reliant on operator time or expertise. This method of tract identification may be useful as DTI is developed as a potential biomarker for visual acuity.

Current and emerging treatment strategies for children with progressive chiasmatic-hypothalamic glioma diagnosed as infants: a web-based survey.

Treatment of infant hypothalamic chiasmatic glioma (iCHG) is challenging, about 30% of the children progress during chemotherapy. Despite subsequent treatments the 5 year overall-survival rate is only 70%. This study investigates treatment strategies currently applied for progressive iCHG. A web-based questionnaire was sent out to the members of the SIOPE Brain Tumour Group asking for current second and third line strategies at progression during and after the end of first line therapy. The questionnaire was answered by 47 paediatric oncologists from 15 countries. iCHG progressing during first line therapy with carboplatin-vincristine would be considered for treatment with alternative chemotherapy by 17 (36%) and with surgery plus chemotherapy by 27 respondents (58%). Components suggested for second line were vinblastine (62%), cisplatin (34%) and cyclophosphamide (26%). For third line therapy bevacizumab (BVZ) was considered as suitable by respondents in 53% (often with irinotecan 40%) and vinblastine by 34% respectively. Experience with BVZ in CHG is shown by 53% of respondents regarding at least 95 patients (median treated 1-5 patients per respondent at any age) with a median BVZ administration over 12 months. Effectiveness was reported varying between stable disease and regression while complications were rarely stated (proteinuria, hypertension, bleeding). BVZ would be available to 85% of respondents as therapeutic option for iCHG patients. Multiple anti-neoplastic drug regimens are applied for progressive iCHG, partly considered in combination with surgery if safely feasible. BVZ is commonly used at a satisfactory level in third line, mainly combined with irinotecan.

Prechiasmatic transection of the optic nerve in optic nerve glioma: technical description and surgical outcome.

Optic pathway glioma (OPG) encompasses a spectrum of findings ranging from lesions confined to the optic nerve only, lesions affecting the optic chiasm and hypothalamus, and lesions with diffuse involvement of a large part of the optic pathway and neighboring structures. The majority of pediatric low-grade astrocytomas in the optic/chiasmatic region are typical pilocytic astrocytoma. The rest of them (10 %) may be other gliomas such as fibrillary pilomyxoid astrocytoma (grade 2 WHO). The postsurgical local recurrence rate of 55 to 76 % has been reported in some histological subtypes such as pilomyxoid astrocytoma (grade 2). Performing a prechiasmatic transection might offer a new surgical option to avoid further tumor growth toward the chiasm in the optic nerve glioma with predominantly orbital manifestations. In this retrospective study, four patients (three children, two without neurofibromatosis type 1 (NF1), and one with NF1 and one adult without NF1) with optic nerve glioma without involvement of the chiasm but blindness, disfiguring proptosis, and pain of the affected eye were included. The surgical approach was performed as a combined approach from pterional extradural and intradural. Without any exceptions, vision of the contralateral eye could be preserved and did not show any deterioration after surgery or during the follow-up time between 17 and 106 months. Furthermore, in all patients, gross total tumor resection could be achieved. During follow-up observation in all patients, no further tumor progress or recurrences could be observed. None of the patients were treated postoperatively by radiotherapy or chemotherapy. Prechiasmatic transection of the optic nerve in optic nerve glioma without affecting the chiasm might offer a surgical treatment option to control tumor growth and to preserve vision of the contralateral eye.

High-Dose Intravenous Vitamin C Treatment of a Child with Neurofibromatosis Type 1 and Optic Pathway Glioma: A Case Report.

BACKGROUND In neurofibromatosis type 1 (NF1) disease, the loss of the tumor suppressor function of the neurofibromin gene leads to proliferation of neural tumors. In children, the most frequently identified tumor is the optic pathway glioma. CASE REPORT We describe the case of a 5-year-old child who was diagnosed with NF1 and optic pathway tumor onset at the age of 14 months. Because of the tumor progression, chemotherapy with carboplatin and vincristine was prescribed at this early age and continued for one year. As the progression of disease continued after chemotherapy, the child, at the age of 2.8 years, was started on high-dose intravenous vitamin C (IVC) treatment (7-15 grams per week) for 30 months. After 30 months, the results of IVC treatments demonstrated reduction and stabilization of the tumors in the optic chiasm, hypothalamus, and left optic nerve according to radiographic imaging. The right-sided optic nerve mass seen before IVC treatment disappeared by the end of the treatment. CONCLUSIONS This case highlights the positive effects of treating NF1 glioma with IVC. Additional studies are necessary to evaluate the role of high-dose IVC in glioma treatment.

Peri-gestational risk factors for pediatric brain tumors in Neurofibromatosis Type 1.

BACKGROUND: Individuals with Neurofibromatosis Type 1 (NF1) are strongly predisposed to developing pediatric brain tumors (PBTs), especially optic pathway gliomas (OPGs). Although developmental factors have been implicated in the origins of PBTs in both human and animal studies, associations between early-life factors and PBTs have not been evaluated in individuals with NF1. Our objective was to evaluate associations between peri-gestational characteristics and PBTs in this population. METHODS: We conducted a cross-sectional study, ascertaining questionnaire and medical record data for 606 individuals<18years old who enrolled in the NF1 Patient Registry Initiative (NPRI) from 6/9/2011-6/29/2015. One hundred eighty-four individuals had reported PBT diagnoses, including 65 who were identified with OPG diagnoses. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between PBT and OPG diagnoses and peri-gestational characteristics (prematurity, birth weight, parental age, plurality, family history of NF1, assisted reproductive technology, maternal vitamin supplementation, and parental smoking). RESULTS: We observed no significant associations between any of the assessed characteristics and PBTs overall or OPGs with the exception of birth weight. After controlling for potential confounding variables, we observed a significant positive association between birth weight quartile and OPGs with a HR of 3.32 (95% CI 1.39-7.94) for the fourth (≥3915.5g) compared to the first (≤3020g) quartile (p for trend=0.001). CONCLUSIONS: Consistent with results for PBTs in the general population, these results suggest that higher birth weights increase OPG risk in individuals with NF1.

Malignant transformation of an optic pathway glioma without prior radiation therapy.

Optic pathway gliomas (OPGs) arise from the optic nerves, optic chiasm, and/or hypothalamus and most commonly occur in childhood. Although these tumors can be quite challenging to manage, they are typically low-grade astrocytomas histologically, most commonly pilocytic astrocytomas. The few previously reported cases of malignant degeneration of an OPG occurred after external beam radiation therapy. The authors report the first case in the English literature of an OPG that transformed from a low-grade astrocytoma, with features most consistent with a pilocytic astrocytoma, to a malignant glioma without any exposure to radiation therapy.

Clinical phenotype of South African children with neurofibromatosis 1.

Forty-eight children with neurofibromatosis 1 presenting between 2000 and 2004 were reviewed for their clinical phenotype, and data were compared with published reports. The median age at presentation was 4 years (range 10 days to 12 years). The male to female ratio was similar (22 male:26 female). There were frequencies of café au lait spots, axillary freckling, Lisch nodules, and new mutations comparable to those cited in the literature. Fewer patients had neurofibromas (4%), but more patients had plexiform neurofibromas of the head and neck (16%). Three patients of the 22 who had neuroimaging had optic gliomas (14%). The most consistent disability, with maximum impact, related to the patient's cognitive level of functioning. School problems, defined as learning and behavioral problems observed in the classroom, were reported in 70% of school-aged children (n = 21), compared with international figures of 29.8% to 45%. This high prevalence has reinforced the clinic service policy of formal neuropsychology assessments in all children with reported school problems. In addition, earlier referral of children to the service (preschool n = 18) has enabled formal developmental assessments and planning of specific educational placement to optimize learning. This is the first description of the neurofibromatosis 1 phenotype from the African continent. The multidisciplinary approach to management has proved beneficial in the South African context. The combined clinic has resulted in a holistic approach to patient care, early detection of pathology, consistent therapies across the specialties, and better patient attendance and compliance. (J Child Neurol 2006;21:63-70).

Radiologic features of pediatric thalamic and hypothalamic tumors.

A variety of histologic subtypes of tumor may affect the thalamus and the hypothalamus in the pediatric population. These tumors have radiologic features that are useful in predicting pathology. We discuss the radiologic findings of childhood thalamic and hypothalamic tumors and provide imaging examples.

Spontaneous regression of low-grade astrocytomas in childhood.

An 8-year-old boy with neurofibromatosis type 1 (NF1) and a biopsy-proven juvenile pilocytic astrocytoma of the hypothalamic/chiasmatic region was followed with serial MRIs over 4 years. Spontaneous tumor regression was followed by progression and biopsy; 6 months later, the tumor regressed again. This bimodal regression is rare, but highlights the variable natural history of low-grade gliomas in children with NF1 and the difficulty in evaluating response of such tumors to therapy.

Initial management of children with hypothalamic and thalamic tumors and the modifying role of neurofibromatosis-1.

Diencephalic gliomas may be grouped into 2 clinical categories. Optic pathway/hypothalamus gliomas (OPG) arise primarily from a slower-growing juvenile pilocytic astrocytoma, and thalamic gliomas arise primarily from a fibrillary astrocytoma which can become clinically and histologically more aggressive. Children with OPG have an excellent long-term prognosis with a 10-year survival of over 85%. The major therapeutic challenge for these patients is to maximize their quality of life by preserving visual and endocrine function while minimizing treatment-related morbidity. Treatment is often initiated at diagnosis in infants and toddlers who have a major visual impairment or the diencephalic syndrome. The judicious application of chemotherapy may serve to forestall the need for radiotherapy or surgery. Children with neurofibromatosis-1 (NF-1) usually have a more indolent course. Tumors may grow more slowly or occasionally regress spontaneously. However, over 90% of children with OPG without NF-1 will require some form of therapy. Patients with thalamic gliomas present with a shorter history, often with hydrocephalus. Surgical intervention is often required to relieve intracranial pressure and establish the histologic identity of the tumor. Over 75% of these tumors will become locally aggressive. Current multimodality therapy is relatively ineffective. The bithalamic variant behaves similarly to a pontine glioma.

Clinical Characteristics, Including Endocrinological Changes, of Optic Glioma in Children

PURPOSE: Optic glioma is a primary tumor arising from the optic nerve and/or chiasm. When located in the hypothalamus, it can produce endocrine signs such as diencephalic syndrome, diabetes insipidus, and panhypopituitarism, before and after treatment. We reviewed the clinical features of optic gliomas, especially the endocrinologic manifestations before/after treatment. METHODS: Retrospective clinical characteristics were reviewed. Thyroid function test, combined anterior pituitary hormone test, and growth hormone provocation test were performed before and after surgical resection or radiotherapy. RESULTS: Twenty one patients (male: female 9:12, mean age, 6 yr) diagnosed by pathologic specimens were included. Initial manifestations were decreased visual acuity (47.6%), headache/vomiting (33.3%), diencephalic syndrome (28.6%), nystagmus (23.8%), strabismus (9.5%), proptosis (4.8%), and hydrocephalus (4.8%). Ninteen optic gliomas (90.5%) were in the intracranial location. The other 2 optic gliomas were confined in the orbital cavity, which were associated with neurofibromatosis-1. Endocrinologic review: There were no endocrinologic symptoms or signs in all patients before operation. But there were multiple hypothalamic-pituitary hormonal deficiencies, including growth hormone deficiency (85.7%; complete 71.4%, partial 14.3%), hypothyroidism (64.7%), diabetes insipidus (53%; persistent 41.2%, transient 11.8%), ACTH deficiency (28.6%), and sexual precocity (5.9%), postoperatively. CONCLUSION: We suggest that early-onset of tumor, especially with diencephalic syndrome, and/or intracranial involvement can be considered as a bad prognostic factor. While optic glioma is a pathologically benign tumor, it is not so clinically benign as thought, because of possible permanent hypopituitarism and diencephalic syndrome. Therefore, we have to carefully follow up the patients to look for the complications, such as hypopituitarism, of this tumor after operation.

Clinical Characteristics, Including Endocrinological Changes, of Optic Glioma in Children

PURPOSE: Optic glioma is a primary tumor arising from the optic nerve and/or chiasm. When located in the hypothalamus, it can produce endocrine signs such as diencephalic syndrome, diabetes insipidus, and panhypopituitarism, before and after treatment. We reviewed the clinical features of optic gliomas, especially the endocrinologic manifestations before/after treatment. METHODS: Retrospective clinical characteristics were reviewed. Thyroid function test, combined anterior pituitary hormone test, and growth hormone provocation test were performed before and after surgical resection or radiotherapy. RESULTS: Twenty one patients (male: female 9:12, mean age, 6 yr) diagnosed by pathologic specimens were included. Initial manifestations were decreased visual acuity (47.6%), headache/vomiting (33.3%), diencephalic syndrome (28.6%), nystagmus (23.8%), strabismus (9.5%), proptosis (4.8%), and hydrocephalus (4.8%). Ninteen optic gliomas (90.5%) were in the intracranial location. The other 2 optic gliomas were confined in the orbital cavity, which were associated with neurofibromatosis-1. Endocrinologic review: There were no endocrinologic symptoms or signs in all patients before operation. But there were multiple hypothalamic-pituitary hormonal deficiencies, including growth hormone deficiency (85.7%; complete 71.4%, partial 14.3%), hypothyroidism (64.7%), diabetes insipidus (53%; persistent 41.2%, transient 11.8%), ACTH deficiency (28.6%), and sexual precocity (5.9%), postoperatively. CONCLUSION: We suggest that early-onset of tumor, especially with diencephalic syndrome, and/or intracranial involvement can be considered as a bad prognostic factor. While optic glioma is a pathologically benign tumor, it is not so clinically benign as thought, because of possible permanent hypopituitarism and diencephalic syndrome. Therefore, we have to carefully follow up the patients to look for the complications, such as hypopituitarism, of this tumor after operation.