The treatment efficacy of radiotherapy for optic nerve sheath meningioma.

OBJECTIVES: Optic nerve sheath meningioma (ONSM) is a rare benign tumour that accounts for approximately 2% of all orbital tumours. Radiotherapy has gradually become an important treatment for ONSM because of its good effect in preserving or improving vision. We aimed to explore the effect of radiotherapy on tumour control and vision preservation/improvement in patients with ONSM. METHODS: Forty-three patients with primary ONSM treated in our institution from 2015 to 2021 were enrolled. The irradiation dose was from 50.4 to 54 Gy with 28-30 fractions. We evaluated the tumour volume on MRI or CT, and visual acuity before and after the radiotherapy. RESULTS: Thirty-four patients (79%) experienced a vision decrease at diagnosis. The mean duration of follow-up was 54.1 months (ranges: 18-93, median: 56). Among 25 patients who had tumour evaluation using MRI, 16 patients (37.2%) showed stable tumours, 7 patients (16.3%) had tumour shrinkage, but 2 patients (4.7%) experienced tumour progression. Among the 39 patients performing vision acuity evaluation, 16 patients (37.2%) had vision improvement or recovery. 16 of the 23 patients without vision improvement demonstrated severe visual loss at diagnosis. Two patients had evidence of tumour progression during the follow-up. Additionally, 4 (10.2%) patients had dry eyes, 7 (17.9%) patients experienced watery eyes, and 3 (7.7%) patients had eye swelling. Patients with vision loss for more than 12 months had a lower possibility of vision recovery than those with vision loss for less than 12 months. CONCLUSIONS: Radiotherapy such as IMRT, VMAT, and 3D-CRT plays an important role in the treatment of ONSM. The probability of vision recovery is lower in patients with severe vision loss at diagnosis or the duration of vision loss is more than 12 months.

[Results of radiation therapy for optic nerve sheath meningioma]. / Rezul'taty luchevogo lecheniya meningiomy obolochki zritel'nogo nerva.

Optic nerve sheath meningioma (ONSM) is a slow-growing benign tumor that tends to extend intracranially. The tumor is characterized by vision disturbance, optic nerve atrophy and edema. At present, radiotherapy is recommended as the treatment of choice for ONSM. PURPOSE: To assess the neuro-ophthalmic symptomatology of ONSM and how it changes in response to radiotherapy. MATERIAL AND METHODS: In the period from 2004 to 2018, 112 patients with ONSM aged 17 to 76 years underwent stereotactic radiotherapy. In 91 patients, visual functions varied from light perception to 1.0; in 21 patients the affected eye was blind. The prospective follow-up of 103 patients lasted 6 months to 10 years (mean follow-up duration was 57 months). Studied patients underwent either conventional fractionated radiotherapy with Novalis (n=88) or hypofractionation radiotherapy with CyberKnife (n=24). RESULTS: According to ophthalmological examination, in 60.5% of cases an improvement of visual functions was observed, 39.5% of patients had visual functions remain stable at the initial level. No vision impairment during irradiation was detected. Vision deterioration in the long-term follow-up was observed in 2 patients: extended tumor growth in one case and radio-induced retinopathy in the other. CONCLUSION: The study showed that this method of treatment for ONSM is effective and safe, allowing preservation of visual functions and in some cases - its improvement, while tumor growth remains under control.

Radiotherapy for the treatment of optic nerve sheath meningioma: A systematic review and meta-analysis.

OBJECTIVES: The management of Optic Nerve Sheath Meningiomas (ONSM) has suffered a significant shift due to new radiation techniques. However, there is no conclusive information on which approach presents better results in the literature. This meta-analysis aims to evaluate the outcomes of different radiotherapy (RT) modalities in the management of ONSM. METHODS: A systematic review based on an electronic search was performed in MEDLINE, EMBASE, Cochrane, and Lilacs databases. Eligible studies included patients with ONSM treated with RT. Two reviewers independently assessed the eligibility of potential studies, extracted data, and performed the meta-analysis. Outcomes of interest were tumor control, visual acuity (VA), visual field, and complications. RESULTS: Thirty-nine non-comparative studies involving 736 eyes with ONSM treated with RT were included. Six different techniques were studied: 2-dimensional RT (2DRT), 3D-conformal RT (3CRT), Stereotactic Fractionation RT (SFRT), stereotactic radiosurgery (SRS), intensity-modulated RT (IMRT), and proton beam therapy (PBT). With a mean follow-up period of 46 months, tumor control was 97,4% (95% CI: 98-100%). No difference was observed regarding the rate of final VA post-treatment among the modalities. The 3CRT showed substantially higher rates of complication than other techniques. CONCLUSIONS: RT produces remarkable tumor control. New radiation modalities such as SFRT, IMRT, SRS, and PBT resulted in better therapeutic results with fewer complications than 2DRT and 3CRT. Thus, they should be the preferential choices for treating ONSM regardless of initial clinical presentation.

Surgical Treatment of Bilateral Optic Nerve Sheath Meningioma: 2-Dimensional Operative Video.

Even though intracranial meningiomas commonly invade the optic canals, true optic nerve sheath meningiomas are extremely rare. They are insidious lesions that frequently grow in 4 stages, leading to progressive visual loss.1-4 Frequently, management includes observation for asymptomatic patients, and fractioned stereotactic radiotherapy with progressive visual loss.1,3 However, surgery is avoided due to the risk of perioperative visual loss.2-4 However, many of these cases present in the early stage of tumor growth, where an arachnoidal plane is still present, and vision can be saved by microsurgical tumor resection.2 Here we present the case of a 33-yr-old female presenting with a 3-wk history of blurred vision. Neuroimaging depicted an enhancing lesion along both optic nerves consistent with bilateral optic nerve sheath meningioma. Neuroophthalmological examination showed inferior cut of visual field bilaterally, more extensive on the left eye. Acuity was 20/20 on both eyes. Microsurgical resection of the tumor was performed through left supraorbital craniotomy, with the goal of eliminating intracranial extension and stabilizing visual function.5 The optic canal was unroofed with diamond bit drill under copious irrigation. A remarkable improvement of her visual field was observed with maintenance of acuity at 20/20 on follow-up. As the patient is attempting pregnancy, she is closely monitored without radiation. Surgery can be offered as a primary treatment of optic nerve sheath meningiomas, especially in early stages, with likely preservation and, in some cases, improvement of visual function.6 The patient consented to the procedure and the use of image. Images at 1:46 and 3:48 reprinted from Al-Mefty O, Operative Atlas of Meningiomas. 1998: Raven Press; Philadelphia, PA, with permission from LWW. Image at 2:57 reprinted from Rassi et al2; © Anil Can, 2018, used with permission. Image at 9:27 in public domain/age.

Optimal management in optic nerve sheath meningioma - A multicentre study and pooled data analysis.

Optic nerve sheath meningiomas (ONSMs) are rare, benign neoplasms of the anterior visual pathway. The optimal modality of radiotherapy for treatment has not yet been established. This is the first study to show significant difference in visual outcomes between radiotherapy subtypes in the management of ONSM. We performed a retrospective analysis of visual outcomes and side effects in ONSM patients treated with radiotherapy at three centres in Sydney, Australia, between 2000 and 2016. 15 patients with ONSM were included, and visual outcomes (visual acuity, visual fields, colour vision, OCT retinal nerve fibre layer thickness and radiological tumour response) and treatment toxicities were assessed. Pooled data analysis of available studies was also performed. Statistical analysis was performed with binomial, two-tailed chi-squared tests and Fisher exact tests. In our cohort a significant majority experienced improved visual field (p = 0.046), stable or improved visual acuity (p = 0.0017) and colour vision (p = 0.015) after fractionated radiotherapy. Pooled analysis with strict inclusion criteria found 3D conformal radiotherapy to offer significantly poorer visual acuity compared to fractionated stereotactic radiotherapy (p = 0.008). When all published studies were included, stereotactic radiosurgery was superior to 3D conformal methods (p = 0.035), and equivalent to other fractionated methods. 3D conformal methods also had significantly higher rates of long-term side effects. These results support the use of fractionated radiotherapy and radiosurgery for ONSM treatment, however 3D conformal methods cannot be recommended.

Rosette-forming Glioneuronal Tumor in the Optic Pathway of a Child.

Rosette-forming glioneuronal tumor is a rare World Health Organization grade I neoplasm, primarily involving the posterior fossa. Most cases have been reported in young adults. Although maximal surgical resection is advocated, a precise treatment modality is yet to be established. We describe an unusual presentation of rosette-forming glioneuronal tumor occurring in the optic pathway in a child. As the site of the tumor was not amenable to resection, he underwent radiotherapy and is currently well on follow-up.

Retrospective analysis of fractionated intensity-modulated radiotherapy (IMRT) in the interdisciplinary management of primary optic nerve sheath meningiomas.

BACKGROUND: As optic nerve sheath meningiomas (ONSM) are rare, there are no prospective studies. Our retrospective analysis focusses on a cohort of patients with uniform disease characteristics all treated with the same radiotherapy regimen. We describe treatment decision making, radiotherapy planning and detailed neuro-ophthalmological outcome of the patients. METHODS: 26 patients with unilateral ONSM extending only to the orbit and the optic canal were evaluated for neuro-ophthalmological outcome. Radiation treatment was planned in a simultaneous integrated boost approach to gross tumor volume (GTV) + 2 mm / 5 mm to 54 Gy / 51 Gy in 1.8 Gy / 1.7 Gy fractions. Follow-up was done by specialized neuro-ophthalmologists. Visual acuity and visual field defects were evaluated after therapy as well as during follow-up. RESULTS: Interdisciplinary treatment decision for patients with ONSM follows a rather complex decision tree. Radiation treatment planning (equivalent uniform dose (EUD), maximum dose to the optic nerve) improved with experience over time. With this patient selection visual acuity as well as visual field improved significantly at first follow-up after treatment. For visual acuity this also applied to patients with severe defects before treatment. Long term evaluation showed 16 patients with improved visual function, 6 were stable, in 4 patients visual function declined. Interdisciplinary case discussion rated the visual decline as radiation-associated in two patients. CONCLUSIONS: With stringent patient selection radiotherapy for unilateral primary ONSM to 51 Gy / 54 Gy is safe and leads to significantly improved visual function. Interdisciplinary treatment decision and experience of the radiation oncology team play a major role.

Long-term treatment outcomes of patients with primary optic nerve sheath meningioma treated with stereotactic radiotherapy.

We analysed the long-term outcomes of patients with primary optic nerve sheath meningioma (ONSM) treated with stereotactic radiotherapy (SRT). 26 patients with primary ONSM were treated with SRT between 2004 and 2013 at a single institution. SRT was delivered with image guidance to a median dose of 50.4 Gy in 28 fractions. 4 patients had prior surgical debulking. At a median radiological follow-up of 68 months, the MRI based tumour control was 100%. Visual acuity improved in 10 (38.4%), remained stable in 10 (38.4%) and was reduced in 6 (23.1%) patients following treatment. Stable or improved vision post-treatment was seen in 92.3% of patients with good pre-treatment vision (best corrected visual acuity 6/18 or better), compared to only 61.5% of patients with poor pre-treatment vision (best corrected visual acuity 6/24 or worse). Overall, the treatment was well tolerated with no Grade 2 or greater acute toxicity. Minimal other ophthalmic complications were seen with only one patient developing late onset Grade 3 radiation retinopathy.

Efficacy of intensity-modulated radiation therapy for optic nerve sheath meningioma.

PURPOSE: The present study examined the efficacy and complications associated with intensity-modulated radiation therapy (IMRT) for optic nerve sheath meningioma (ONSM) in 15 cases and compared visual function before and after treatment. METHODS: Consecutively diagnosed patients with ONSM treated with IMRT were evaluated from 2012 to 2017. We categorized ONSM with three growth patterns (diffuse, fusiform, or globular). Visual acuity, visual fields, and optic disc findings were assessed before and after IMRT. Ocular and systemic complications were evaluated during and after treatment. RESULTS: The 15 patients selected for analysis ranged in age from 33 to 77 years. Post-treatment observation periods were 8 to 57 months. After IMRT, tumor enlargement was not detected in any eyes, and tumor reduction was seen in 2 eyes. At final post-treatment follow-up, eyes with fusiform and globular growth maintained better visual acuity compared with pre-treatment, whereas 2 of 5 eyes with diffuse growth showed reduced vision. Five eyes with no apparent optic disc abnormality maintained better visual acuity compared with pre-treatment, whereas 8 of 10 eyes with disc edema and atrophy remained stable or showed reduced vision. Improvements were seen in all 5 eyes with optic discs negative for pre-treatment abnormalities. Final post-treatment visual field abnormalities improved in 11 eyes. All adverse events identified during IMRT improved rapidly during the treatment period. CONCLUSION: IMRT for the treatment of ONSM achieved improvement and preserved visual function. In particular, early treatment with IMRT before the appearance of optic disc abnormalities can be more effective for improving visual function.

Visual Outcomes of Fractionated Radiotherapy in Optic Nerve Sheath Meningioma: A Retrospective Study.

BACKGROUND: Optic nerve sheath meningioma (ONSM) is a rare benign tumour of the optic nerve sheath that can lead to blindness if untreated. Radiotherapy is commonly accepted as being the treatment of choice. We conducted a retrospective monocentric study to assess the effect of radiotherapy on visual outcomes and tumour control in patients with ONSM. PATIENTS AND METHODS: The charts of all patients affected by ONSM between 1994 and 2016 were reviewed retrospectively. Inclusion criteria were: having been followed by our department, initial visual acuity (VA) better than no light perception, and stereotactic fractionated radiotherapy. VA (Snellen), colour vision (Ishihara), and visual field mean defect (in dB), as well as ONSM size (on MRI) were compared before and after radiotherapy. Visual function was considered improved if two or more criteria improved, stabilised if none or only one criterion changed, and worsened if two or more criteria worsened. The Wilcoxon signed-rank test was used to assess the effect of radiotherapy (significant if p value < 0.05). RESULTS: VA improved or stabilised in 13/16 patients (81.25%), with median VA improving from 0.1 logMAR (8/10) to 0 logMAR (10/10) (p value = 0.0134). Colour vision improved or stabilised in 11/15 patients (73.33%), with median results improving from 5/13 to 12/13 (p value = 0.3212). The visual field mean defect improved in 13/15 patients (86.66%), and the median mean defect (MD) improved from 10 dB to 4 dB (p value = 0.0106). The size of the ONSM diminished or stabilised in 100% of our patients. No adverse events of radiotherapy were either reported or detected. CONCLUSION: Fractionated radiotherapy is a safe procedure and may improve visual function in patients with ONSM.

Long-term efficacy of fractionated conformal radiotherapy for the management of primary optic nerve sheath meningioma.

BACKGROUND/AIM: Fractionated conformal radiotherapy (FCRT) is now used to treat vision-threatening optic nerve sheath meningioma (ONSM), but long-term efficacy and safety data are lacking; the purpose of this study was to assess these key data. METHODS: This is a retrospective chart review with prospective follow-up of adult patients treated with FCRT for primary ONSM at four academic medical centres between 1995 and 2007 with ≥10 years of follow-up after treatment. RESULTS: 16 patients were identified with a mean post-treatment follow-up of 14.6 years (range: 10.5-20.7 years). The mean age at symptom onset was 47.6 years (range: 36-60 years). FCRT was performed at a mean of 2.3 years after symptom onset (range: 0.2-14.0 years). At last follow-up, visual acuity had improved or stabilised in 14 of the 16 (88%) patients, and 11 (69%) had retained or achieved ≥20/40. The mean deviation on automated perimetry remained stable (-14.5 dB pretreatment vs -12.2 dB at last follow-up; p=0.68, n=10). Two (11%) patients had persistent pain, proptosis or diplopia, compared with six (38%) pretreatment (p=0.11). Two (13%) patients developed radiation retinopathy more than 6 months after completion of therapy, one (50%) of whom had worse visual acuity compared with pretreatment. No patient developed tumour involvement or radiation damage in the fellow eye. CONCLUSION: FCRT stabilises or improves visual function in patients with primary ONSM and is associated with a low risk of significant ocular sequelae. This treatment should be considered instead of surgery in patients with primary ONSM who require intervention due to loss of visual sensory and/or ocular motor function.

Endovascular glue embolization of a radiation-induced lenticulostriate artery pseudoaneurysm in a pediatric patient with optic pathway glioma: Case report and review of literature.

Radiation-associated vascular changes most commonly present in the form of stenosis, thrombosis and occlusion. However, development of intracranial aneurysms secondary to radiation is far less common and often manifests with rupture. These aneurysms are difficult to treat and associated with high morbidity and mortality when ruptured compared with saccular aneurysms unrelated to radiation treatment. Both surgical and endovascular options are available for treatment of these aneurysms. We present a young patient with a radiation-induced intracranial pseudoaneurysm arising from the lenticulostriate branch of the left middle cerebral artery (MCA); this developed 1 year 4 months after 59.4 Gy of focused radiation to the suprasellar pilomyxoid astrocytoma. The patient successfully underwent endovascular glue embolization of the aneurysm and occlusion of the lenticulostriate artery after unsuccessful trapping of the aneurysm and occlusion of the parent artery using coils. She developed transient hemiparesis of the right side following the procedure, which was managed conservatively. We performed a complete review of the literature dealing with the radiation-induced intracranial aneurysms, their presentation, treatment and outcome.

Early intervention using high-precision radiotherapy preserved visual function for five consecutive patients with optic nerve sheath meningioma.

BACKGROUND: There has been a paradigm shift in the treatment for optic nerve sheath meningioma (ONSM) from surgery to fractionated stereotactic radiotherapy (FSRT) in other countries. However, FSRT has seldom been performed in Japan. The purpose of this retrospective study is to reconfirm the effectiveness of early intervention with precision radiotherapy for ONSM reported in our previous study. METHODS: Five consecutive patients with ONSM were retrospectively analyzed. All patients underwent intensity-modulated radiotherapy (IMRT) or FSRT. They received the early interventions between 1.5 and 7 months after deterioration of the disease. The median dose was 52.8 Gy (range 46.0-59.4 Gy) and the median number of fractions was 25 (range 22-33). RESULTS: All patients experienced reestablishment of vision at the median follow-up time of 36 months (range 18-54 months). Four of them noted early improvement of visual deficits during the treatment course (range 2-4 weeks) and the remaining patient improved 3 weeks after completion of IMRT. The median tumor reduction was 53% (range 39-75%). One patient with diabetes mellitus developed retinal bleeding as a result of radiation retinopathy 16 months after IMRT, although the doses were acceptable. The remaining 4 patients have no late toxicity at the follow-up time of 31-54 months. CONCLUSIONS: A paradigm shift is necessary from surgery to early intervention using precision radiotherapy for the treatment of ONSM in Japan.

Proton Beam Irradiation: A Safe Procedure in Postequatorial Extraocular Extension From Uveal Melanoma.

PURPOSE: This study was performed to show long-term outcomes concerning metastasis rates and local recurrence rates after primary proton beam therapy in uveal melanoma with posterior extraocular extension (EOE) with the main focus on optic nerve invasion. DESIGN: Retrospective case series. METHODS: All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma with posterior EOE between July 1998 and August 2010 were included. EOE was detected either upon sonography at primary examination or during the surgical application of tantalum clips onto the sclera. Ultrasound was performed in each patient before surgery, and if EOE was detected, a magnetic resonance imaging (MRI) scan was performed to confirm EOE. All patients with tumors exceeding 6 mm in thickness or abutting the optic disc received a 1.5 Tesla MRI scan after clip surgery. To assess EOE during follow-up, either ultrasound examinations or-if initially detected only by MRI-MRI scans were performed during follow-up. RESULTS: A total of 27 patients underwent primary proton beam therapy. The EOE was separated into 3 growth types: optic nerve infiltration in 10 patients, vortex vein infiltration in 9 patients, and transscleral growth postequatorially in 8 patients. No local recurrences were found during the overall median follow-up of 80 months (11-168 months). Metastasis rates correlated with AJCC stages but not EOE volume. CONCLUSION: This study shows that posterior EOE can safely be treated by proton beam therapy, even if the optic nerve is infiltrated. MRI enables safe detection of optic nerve invasion.

Visual Outcomes and Local Control After Fractionated Stereotactic Radiotherapy for Optic Nerve Sheath Meningioma.

PURPOSE: To review the outcomes of patients with optic nerve sheath meningiomas (ONSM) treated with fractionated stereotactic radiotherapy. METHODS: Patient characteristics, treatment, and outcomes were analyzed for all patients with primary and secondary ONSM treated from 2001 to 2012. Clinically significant visual acuity change was defined as a 2-line change on the Snellen eye chart from pre-fractionated stereotactic radiotherapy. RESULTS: Forty-one patients were treated: 23 patients with primary ONSM and 18 patients with secondary ONSM. The median age at diagnosis was 56 years. The median visual follow up was 3.8 years and the median radiologic follow up was 4.4 years. At diagnosis, 36% had normal vision (20/20-20/40), 10% had mild impairment (<20/40-20/60), 20% had moderate visual impairment (<20/60-20/200), 27% had severe impairment (<20/200), and 7% had no light perception. Common acute side effects were headache (32%) and nausea (15%); 15% of patients required corticosteroids during stereotactic radiotherapy. Chronic toxicities included retinopathy (7%), pituitary dysfunction (13%), chronic ocular pain (5%), and cataracts (2%). Visual acuity was stable in 65%, improved in 27%, and decreased in 8% of patients. Visual fields were stable in 70%, improved in 21%, and reduced in 9%. Actuarial 5-year local control rates were 100% for primary ONSM and 88% for secondary ONSM. Actuarial 5-year visual preservation rates were 100% for primary ONSM and 86% for secondary ONSM. CONCLUSIONS: Fractionated stereotactic radiotherapy for primary and secondary ONSM was well tolerated and provides excellent local control and visual preservation. Longer follow up is required to determine the risk of late ocular and pituitary sequelae.

Natural history of primary paediatric optic nerve sheath meningioma: case series and review.

PURPOSE: To study the natural history, clinical and radiological characteristics of primary paediatric optic nerve sheath meningioma (PPONSM). METHODS: Retrospective study of eight paediatric patients who were treated between 1994 and 2016 at the University Hospital Zurich, Switzerland and the Royal Adelaide Hospital, Australia. Clinical records and imaging studies were reviewed. RESULTS: The mean age at presentation was 11 years (range: 6-17 years). There were six female patients and two male patients. 2/8 patients had associated neurofibromatosis type 2. Patients were followed up for 71-297 months (mean 156±70 months). 6/8 patients were observed through the course of their disease and 2/8 patients were treated with radiotherapy. 2/8 patients who were observed had minimal change in vision and did not experience tumour growth after long-term follow-up. CONCLUSIONS: This is the largest PPONSM case series with long-term data on patients treated conservatively. We highlight that a small subset of these tumours are indolent and can be managed using observation alone.

Radiation Therapy for Optic Pathway and Hypothalamic Low-Grade Gliomas in Children.

PURPOSE: The long-term survival of pediatric patients with optic pathway or hypothalamic low-grade glioma (LGG) who receive radiation therapy (RT) has not been previously assessed. METHODS AND MATERIALS: A retrospective study was performed of all patients with optic-hypothalamic pediatric LGG treated with RT at a single institution. Eligible patients were aged ≤21 years at the time of RT and had localized LGG diagnosed by neuroimaging or histology. The median RT dose was 54 Gy, delivered in 30 fractions. Event-free survival (EFS) was defined as survival without progression or secondary high-grade glioma. Days were counted from the first day of RT. RESULTS: Eighty-nine patients were included in the study, with a median follow-up period of 12.5 years. Of the patients, 14 had neurofibromatosis type 1 (NF-1). The 10-year EFS rate was 61.9% (95% confidence interval [CI], 31.2%-82.1%) for patients with NF-1 and 67.5% (95% CI, 54.8%-77.3%) for those without NF-1. The 10-year overall survival rate was 92.3% (95% CI, 56.6%-98.9%) for patients with NF-1 and 98.4% (95% CI, 89.1%-99.8%) for those without NF-1. Pre-RT chemotherapy (which was more commonly given to younger patients) was associated with reduced EFS, whereas younger age was associated with reduced overall survival. Possible RT-induced neoplasms developed in 8 patients, including 4 with NF-1. The 10-year cumulative incidence of clinically significant vasculopathy was 7.1% (95% CI, 2.9%-13.9%); vasculopathy did not develop in any child aged >10 years at the commencement of RT. CONCLUSIONS: RT is an effective treatment for optic-hypothalamic LGG. Older children without NF-1 have a low risk of late toxicity. RT can be considered for selected younger patients or individuals with NF-1 as a salvage treatment after progression.