Optic pathway gliomas

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term outcomes of symptomatic optic pathway glioma: 32-year experience at a single Western Australian tertiary pediatric oncology center

Introduction

Optic pathway gliomas (OPGs) are associated with significant risk of visual and endocrine morbidity, but data on long-term outcomes in symptomatic patients is sparse. This study reviews the clinical course, disease progression, survival outcomes and long-term sequelae in pediatric patients with symptomatic OPGs in our institution over three decades.

Methods

Retrospective review of patients with symptomatic OPG treated in a single tertiary pediatric oncology center from 1984 to 2016.

Results

A total of 37 patients were diagnosed with symptomatic OPG. Decreased visual acuity was the commonest presenting symptom (75.7%). Surgical intervention was performed in 62.2%; 56.5% underwent biopsy, 26.1% surgical debulking and 17.4% had orbital decompression with cystic fenestration and cosmetic optic nerve excision at different treatment intervals. CSF diversion was performed in 47.8% patients. Histopathologic examination confirmed 86% to be pilocytic astrocytoma and 1 ganglioglioma. 46% received chemotherapy and 48% had radiotherapy, at different intervals. Median follow-up was 13.74 years. In NF1 patients, overall survival (OS) was 100% at 5 years and 55.6 ± 24.8% at 25 years while progression-free-survival (PFS) was 50 ± 15.8% at 5 and 20 years. In non-NF1 patients, OS was 96.2 ± 3.8% at 5 years and 87.4 ± 9% at 25-years. 5-year PFS was 53.8 ± 9.8% and 25-year PFS was 49.0 ± 10%. Cumulative PFS was 53 ± 8.3% at 5 years and 49.7 ± 8.4% at 20 years while cumulative OS was 97.2 ± 2.7% at 5 years and 77.5 ± 10.8% at 25 years. 59.5% patients developed post-operative endocrinopathy. Long-term vision was normal in 8.1%, improved in 13.5%, stabilized in 40.5% but worsened in 37.8% patients. Three patients treated with radiotherapy developed second brain tumors.

Conclusion

25-year OS in this cohort was 77.5% but survivorship carried significant long-term morbidities including radiation-induced second malignant brain tumors.

Rethinking the Management of Optic Pathway Gliomas: A Single Center Experience

Background

Optic pathway gliomas (OPGs) are rare neoplasms in children with an unpredictable clinical course. Approximately 15% of OPGs occur in patients affected by neurofibromatosis type 1 (NF1): the clinical course of these cases is more indolently than sporadic ones, and NF1 patients less frequently require treatment including surgery. Instead, over 90% of sporadic OPGs require one or more therapeutic approaches. The management of OPG is controversial. They are also characterized by a high risk of morbidity including hypothalamic damage, endocrine deficits, visual deficit and/or neurological impairment.

Materials and Methods

In this paper, we evaluated visual and endocrinological outcomes of a population of OPG followed at our center from 2013 to 2021, with a particular emphasis on the role of surgery.

Results

Twenty-six patients were included in this study (mean age of 40.7 months). Tumor location on imaging was described by the Dodge classification. Five cases had NF 1. Thirteen cases received biopsy and 13 were partially resected. Histopathology revealed 19 cases of pilocytic astrocytomas, 2 pilomyxoid astrocytoma and 5 ganglioglioma. All the patients required a post-surgical adjuvant treatment according to current indications for low-grade gliomas. Molecular studies (BRAF status and mTOR/pmTOR pathway) have been performed in 24/26 patients, following for the use of target therapy in 11 of these patients. In our study we found that patients underwent biopsy have a better visual and endocrinological outcomes rather than patients with a tumor debulking. The five-year overall survival rate is 98% with a mean follow-up of 60 months.

Conclusions

Many children with OPGs survive with a residual tumor. They suffer from chronic diseases such as endocrine dysfunction, visual disturbance, motor deficits and poor quality of life. All patients need comprehensive diagnostic work-up including neuroimaging, clinical evaluations and neuropathology approach; at the same time, they need therapeutic decisions and concepts for the choice of timing and type of neurosurgical intervention, chemotherapy and target therapy as well as surveillance and rehabilitation to maximize survival and overall functional outcomes. Our study showed that minimal invasive surgery with the purpose of molecular characterization of the tumor is desirable to reduce morbidity correlate to surgery.

Neuroimaging Features of Optic Nerve Hemangioblastoma Identified by Conventional and Advanced Magnetic Resonance Techniques: A Case Report and Literature Review

Optic nerve hemangioblastoma is a very rare benign tumor with only 39 reported cases by now. It appears to be hyperintense on T2-weighted images with a significant enhancement on contrast scans, which are similar to glioma and meningioma. Due to the lack of specificity in MRI manifestations, optic nerve hemangioblastoma is often misdiagnosed. To provide new insights into differential diagnosis of optic nerve hemangioblastoma, we report for the first time an optic nerve hemangioblastoma case employing advanced magnetic resonance techniques including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, and magnetic resonance angiography (MRA). In addition, we have collected all reported optic nerve hemangioblastoma cases and reviewed their neuroimaging findings by MRI and angiography. Our results show that solid-type tumor is the dominant form of optic nerve hemangioblastoma and extensive edema is widely observed. These findings are surprisingly contrary to manifestations of cerebellar hemangioblastoma. Besides the structural features, quantitative indexes including ADC and relative cerebral blood volume (rCBV) ratio, which are significantly elevated in cerebellar hemangioblastoma, may also shed a light on the preoperative diagnosis of hemangioblastoma of optic nerve. Finally, we discuss the critical neuroimaging features in the differential diagnosis between optic nerve hemangioblastoma from optic pathway glioma and optic nerve sheath meningioma.

Neurofibromatosis 1-associated optic pathway gliomas

BACKGROUND

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

PURPOSE

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

Optic pathway-hypothalamic glioma hemorrhage: a series of 9 patients and review of the literature

OBJECTIVEHemorrhage (also known as apoplexy) in optic pathway gliomas (OPGs) is rare. Because of the variable presentations and low incidence of OPG hemorrhages, little is known about their clinical course and the best treatment options. The aim of this work was to review risk factors, clinical course, and treatment strategies of optic glioma hemorrhages in the largest possible number of cases.METHODSA total of 34 patients were analyzed. Nine new cases were collected, and 25 were identified in the literature. Data regarding demographics, radiological and histological features, treatment, and outcome were retrospectively reviewed.RESULTSThe majority of patients were younger than 20 years. Only 3 patients were known to have neurofibromatosis. The histopathological diagnosis was pilocytic astrocytoma in the majority of cases. Five patients had intraorbital hemorrhages, whereas 29 patients had intracranial hemorrhage; the majority of intracranial bleeds were treated surgically. Six patients, all with intracranial hemorrhage, died due to recurrent bleeding, hydrocephalus, or surgical complications. No clear risk factors could be identified.CONCLUSIONSIntracerebral OPG hemorrhages have a fatal outcome in 20% of cases. Age, hormonal status, neurofibromatosis involvement, and histopathological diagnosis have been suggested as risk factors for hemorrhage, but this cannot be reliably established from the present series. The goals of surgery should be patient survival and prevention of further neurological and ophthalmological deterioration.

Visual function assessed by visually evoked potentials in optic pathway low-grade gliomas with and without neurofibromatosis type 1

PURPOSE

To investigate the contribution of full-field transient pattern-reversal visually evoked potentials (PRVEP) on cross-sectional evaluations of visual function in patients with and without neurofibromatosis type 1 (NF1) affected by optic pathway low-grade gliomas (OPLGG).

METHODS

Participants were children and adolescents referred for visual function evaluation and receiving treatment for OPLGG, linked (NF1-OPLGG) or not to NF1 (Non-NF1-OPLGG). An age-adjusted control group was included for comparison. Monocular full-field PRVEPs were recorded from each eye in accordance with ISCEV standards. Parameters of peak-to-peak P100 amplitude (µV) and P100 peak time (ms) were measured. Cutoff normative values obtained from controls for 15' and 60' check sizes were ≥ 9.0 µV for N75-P100 amplitude and ≤ 103.0 ms for P100 peak time. The association of age, gender, tumor resection and NF1 with P100 amplitude reduction and P100 peak time delay was explored by Firth logistic regression modeling.

RESULTS

Participants were 30 patients (15 males, 60% Non-NF1) with ages from 3.6 to 19.9 years (mean ± SD = 9.2 ± 3.8 years; median = 8.4 years) and 19 controls (12 males) with ages from 3.7 to 19.9 years (mean ± SD = 10.4 ± 4.9 years; median = 9.5 years). Overall, 68% of tested eyes presented reduced P100 amplitudes for both check sizes (46% in the NF-1 and 83% in the Non-NF1) and delayed P100 for both check sizes (38% in NF1 and 89% in Non-NF1). Absence of NF1 adjusted for age, gender and tumor resection was significantly associated with marginally reduced P100 amplitude for 15' checks [odds ratio (OR): 6.26; 95% confidence interval (CI) = 0.96-40.94; p = 0.055].

CONCLUSIONS

Full-field PRVEP on cross-sectional evaluations contributed to detect visual dysfunction in two-thirds of patients with OPLGG by highlighting subclinical evidence of visual loss. Abnormalities were more frequent and more severe in OPLGG not linked to NF1 than in NF1-OPLGG; however, there was a difference in surgical management between these groups. PRVEP parameters may provide reliable evidence of visual pathway involvement in OPLGG, helping to hasten treatment before optic atrophy is detected.

MR imaging of neoplastic and non-neoplastic lesions of the brain and spine in neurofibromatosis type I

The aim of this work is to review the MR imaging of neoplastic and non-neoplastic lesions of the brain and spine in neurofibromatosis type I. Neoplastic lesions are optic pathway gliomas, brain stem gliomas, other gliomas of the brain, and peripheral nerve sheath tumors. Structural changes in the brain include unidentified bright objects, macrocephaly, and enlarged corpus callosum. Bony dysplasia changes as sphenoid ridge dysplasia, spinal scalloping, dural ectasia, and meningoceles. Vasculopathy and cortical cerebral and cerebellar malformations of the brain have been reported.

Isolated optic nerve gliomas: a multicenter historical cohort study

OBJECTIVE Isolated optic nerve gliomas (IONGs) constitute a rare subgroup of optic pathway gliomas (OPGs). Due to the rarity of this condition and the difficulty in differentiating IONGs from other types of OPGs in most clinical series, little is known about these tumors. Currently, due to lack of evidence, they are managed the same as any other OPG. METHODS The authors conducted a multicenter retrospective cohort study aimed at determining the natural history of IONGs. Included were patients with clear-cut glioma of the optic nerve without posterior (chiasmatic/hypothalamic) involvement. At least 1 year of follow-up, 2 MRI studies, and 2 neuro-ophthalmological examinations were required for inclusion. RESULTS Thirty-six patients with 39 tumors were included in this study. Age at diagnosis ranged between 6 months and 16 years (average 6 years). The mean follow-up time was 5.6 years. Twenty-five patients had neurofibromatosis Type 1. During the follow-up period, 59% of the tumors progressed, 23% remained stable, and 18% (all with neurofibromatosis Type 1) displayed some degree of spontaneous regression. Fifty-one percent of the patients presented with visual decline, of whom 90% experienced further deterioration. Nine patients were treated with chemotherapy, 5 of whom improved visually. Ten patients underwent operation, and no local or distal recurrence was noted. CONCLUSIONS Isolated optic nerve gliomas are highly dynamic tumors. Radiological progression and visual deterioration occur in greater percentages than in the general population of patients with OPGs. Response to chemotherapy may be better in this group, and its use should be considered early in the course of the disease.

Dynamic Imaging of the Eye, Optic Nerve, and Extraocular Muscles With Golden Angle Radial MRI

Purpose

The eye and its accessory structures, the optic nerve and the extraocular muscles, form a complex dynamic system. In vivo magnetic resonance imaging (MRI) of this system in motion can have substantial benefits in understanding oculomotor functioning in health and disease, but has been restricted to date to imaging of static gazes only. The purpose of this work was to develop a technique to image the eye and its accessory visual structures in motion.

Methods

Dynamic imaging of the eye was developed on a 3-Tesla MRI scanner, based on a golden angle radial sequence that allows freely selectable frame-rate and temporal-span image reconstructions from the same acquired data set. Retrospective image reconstructions at a chosen frame rate of 57 ms per image yielded high-quality in vivo movies of various eye motion tasks performed in the scanner. Motion analysis was performed for a left-right version task where motion paths, lengths, and strains/globe angle of the medial and lateral extraocular muscles and the optic nerves were estimated.

Results

Offline image reconstructions resulted in dynamic images of bilateral visual structures of healthy adults in only ∼15-s imaging time. Qualitative and quantitative analyses of the motion enabled estimation of trajectories, lengths, and strains on the optic nerves and extraocular muscles at very high frame rates of ∼18 frames/s.

Conclusions

This work presents an MRI technique that enables high-frame-rate dynamic imaging of the eyes and orbital structures. The presented sequence has the potential to be used in furthering the understanding of oculomotor mechanics in vivo, both in health and disease.

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.