Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

Incidental Meningiomas: Potential Predictors of Growth and Current State of Management

The rise in availability of neuroimaging has led to an increase in incidentally discovered meningiomas. These tumors are typically asymptomatic and tend to display slow growth. Treatment options include observation with serial monitoring, radiation, and surgery. Although optimal management is unclear, clinicians recommend a conservative approach, which preserves quality of life and limits unnecessary intervention. Several risk factors have been investigated for their potential utility in the development of prognostic models for risk assessment. Herein, the authors review the current literature on incidental meningiomas, focusing their discussion on potential predictive factors for tumor growth and appropriate management practices.

Radiotherapy for Meningioma

Meningiomas are the most common primary intracranial brain tumor, and have a heterogeneous biology and an unmet need for targeted treatment options. Existing treatments for meningiomas are limited to surgery, radiotherapy, or a combination of these depending on clinical and histopathological features. Treatment recommendations for meningioma patients take into consideration radiologic features, tumor size and location, and medical comorbidities, all of which may influence the ability to undergo complete resection. Ultimately, outcomes for meningioma patients are dictated by extent of resection and histopathologic factors, such as World Health Organization (WHO) grade and proliferation index. Radiotherapy is a critical component of meningioma treatment as either a definitive intervention using stereotactic radiosurgery or external beam radiotherapy, or in the adjuvant setting for residual disease or for adverse pathologic factors, such as high WHO grade. In this chapter, we provide a comprehensive review of radiotherapy treatment modalities, therapeutic considerations, radiation planning, and clinical outcomes for meningioma patients.

Long-Term Visual Function After Fractionated Stereotactic Radiotherapy for Primary Optic Nerve Sheath Meningioma: A Retrospective Analysis of 34 Subjects

Objective

To evaluate long-term visual function after fractionated stereotactic radiotherapy (FSRT) for primary optic nerve sheath meningioma (PONSM).

Methods

This 22-year retrospective study included 34 subjects (34 affected eyes) with PONSM who were treated with FSRT exclusively. Subjects with a history of biopsy/resection were excluded. Visual function, including visual acuity (VA) and visual field mean deviation (VF MD), was evaluated at presentation (pre-radiotherapy; pre-RT) and at the final follow-up (post-radiotherapy; post-RT); treatment complications were also evaluated. Treatment success was defined as either stabilization or improvement of visual function.

Results

The median pre-RT VA and pre-RT VF MD were 0.70 logarithm of the minimum angle of resolution (logMAR; range: 0.0–2.9 logMAR) and −15.4 decibels (dB) (range: −31.4 to −3.2 dB), respectively. The median total dose of FSRT was 50 Gy (range: 45–54 Gy) and the median number of fractions was 25 (range: 25–30). The median follow-up interval was 89 months (range: 6–251 months). The median post-RT VA and post-RT VF MD were 0.48 logMAR (range: 0.0–2.9 logMAR) (p = 0.010) and −6.8 dB (range: −20.6 to −1.6 dB) (p = 0.005), respectively. Among the 34 included eyes, VA was successfully treated in 29 eyes (85.3%) and worsened in 5 eyes (14.7%). Of the 14 eyes with both VA and reliable VF MD at pre-RT and post-RT time points, VF MD was successfully treated in 13 eyes (92.8%) and worsened in one (7.2%); overall visual function was successfully treated in 13 eyes (92.8%) and worsened in 1 eye (7.2%). Complications occurred in one subject (2.9%; radiation retinopathy).

Conclusion

Approximately 90% of PONSM subjects exhibited long-term treatment success in terms of VA, VF MD, and overall visual function after FSRT. Additionally, the incidence of complications was low. Therefore, FSRT is effective and safe treatment for PONSM.

Radiotherapy and Radiosurgery in the Management of Optic Nerve Sheath Meningiomas: An International Systematic Review and Meta-Analysis of Twenty Studies

BACKGROUND

Optic nerve sheath meningiomas (ONMs) are often managed with radiotherapy (RT) with the goal of achieving radiographic local control (LC) and preventing deterioration of visual acuity (VA). We aimed to perform a systematic review and meta-analysis of outcomes for patients with ONM treated with RT.

METHODS

The PICOS/PRISMA/MOOSE selection criteria were used to identify studies. Primary outcomes were stable or improved VA and radiographic LC at last follow-up. The secondary outcomes were incidences of radiation-induced retinopathy and xerophthalmia and stable or improved visual fields (VFs). Weighted random-effects meta-analyses using the DerSimonian and Laird methods were conducted to characterize effect sizes. Mixed-effects regression models were used to examine potential correlations between gross tumor volume (GTV) and outcomes.

RESULTS

In total, 444 patients with ONM across 20 published studies were included. The estimated LC rate was 99.8% (95% confidence interval [CI], 98.3%-100%), and the estimated proportion of patients with stable or improved VA or VF was 89.7% (95% CI, 86.2%-92.4%) and 93.3% (95% CI, 89.5%-95.8%), respectively. Estimated incidences of radiation-induced retinopathy and xerophthalmia were 7.2% and 10.1%, respectively. GTV was significantly associated with VA (P = 0.014) with estimated VA rates of 96.4%, 91.4%, and 80.5% for GTVs of 2.0, 3.0, and 4.0 cm³, respectively.

CONCLUSIONS

RT was well tolerated, with excellent LC achieved. Nearly 90% of patients noted either stability or improvement in VA and VF. Larger ONMs were associated with poorer VA.

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.

Efficacy and Safety of Proton Beam Therapy for Primary Optic Nerve Sheath Meningioma

Purpose

Management of optic nerve sheath meningiomas (ONSM) remains challenging. Photon radiation therapy (PhRT) is the most common treatment for sight-threatening ONSM. Proton beam therapy (PBT) is less commonly used because it is more expensive and because there are questions about its efficacy specifically in relation to ONSM. PBT has the theoretical advantage of reducing radiation exposure to adjacent structures. We report the visual outcome of patients with primary ONSM managed at the Fondation Ophtalmologique Adolphe de Rothschild, Paris, France, and treated with PBT at the Centre de Protonthérapie, Institut Curie, Orsay, France.

Methods

We conducted a retrospective review of all patients with primary ONSM who received PBT (either by itself or following surgery) between January 2006 and January 2019. Neuro-ophthalmic examinations were performed at presentation and after radiotherapy, and, when applicable, after surgery. Meningiomas were measured at the time of diagnosis and at each follow-up MRI examination.

Results

Sixty patients (50 women, 10 men; mean age, 45.2±11.1y) were included, of whom 29 underwent surgery. At presentation, 52 (87%) of them had decreased vision (average visual acuity: 0.6 logMAR). Fundus examination showed optic disc swelling (n=27; 46.5%), optic disc pallor (n=22; 37.9%), optic disc cupping (n=2; 3.4%), opto-ciliary shunt (n=8; 13.8%), or choroidal folds (n=5; 8.6%). Otherwise, it was unremarkable (n=7; 12.1%). After treatment, visual function was stable overall. Fundus examination showed pallor (n=47; 83.9%), swelling (n=3; 5.4%), or cupping (n=2; 3.4%) of the optic disc, or was unremarkable (n=5; 8.9%). The visual field of 8 patients worsened, while 3 developed asymptomatic retinal hemorrhages. Tumor shrunk significantly in 8 patients at 1 year after PBT and remained stable in size in all others. Patients with opto-ciliary shunts had significantly worse visual outcome than other patients. Retinal abnormalities were observed in 11 patients during follow-up.

Conclusion

PBT alone or in association with surgery appears to be a safe and efficient treatment for ONSM, reducing the tumor size and stabilizing visual function. The risk of developing radiation retinopathy seems to be higher when patients had upfront surgery.

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.

Primary and Secondary Optic Nerve Sheath Meningioma

Objective  This study was aimed to review issues relating to the recognition, radiographic diagnosis, monitoring, and management of primary and secondary optic nerve sheath meningioma (ONSM). Design  This study is a review of peer-reviewed literature combined with illustrative case studies. Participants and Methods  A literature search was conducted via the PubMed database using pertinent search terms. Selected articles were limited to those written or translated into English. Additional works cited within articles were also included. Individual cases were drawn from the experience of a tertiary academic neuroophthalmic and orbital practice. Tables summarize radiotherapeutic and surgical studies, excluding single case reports and studies focusing on meningioma of intracranial origin. Main Outcome Measurements  Review of reported surgical and radiotherapeutic series is the primary measurement. Results  The natural history of optic nerve sheath meningiomas is primarily characterized by progressive ipsilateral vision loss. Diagnosis is typically based on radiographic imaging findings, with biopsy remaining indicated in some patients. Management strategies may include observation, radiation, and/or surgical intervention, or a combination of these approaches. The role of surgery, especially with respect to primary ONSM (pONSM), remains controversial. Advancement of radiotherapy techniques has shifted modern treatment paradigms in pONSM toward radiation as primary treatment, as surgical outcomes are inferior in major studies. Although radiation remains the treatment of choice in many cases, selected patients may benefit from surgery, especially in the setting of secondary ONSM (sONSM). Conclusion  A wide variety of radiotherapeutic and surgical treatment modalities for ONSM exist. The specific indications for each management strategy continue to be redefined.

Prognostic Factors for Functional Outcome of Patients with Optic Nerve Sheath Meningiomas Treated with Stereotactic Radiotherapy-Evaluation of Own and Meta-Analysis of Published Data

Simple Summary

This article highlights the fractionated stereotactic radiotherapy in the treatment of optic nerve sheath meningioma (ONSM). ONSM, a slow-growing tumor next to the optic nerve, causes over a long period partial or complete blindness. As visual impairments appear and progress slowly in the disease history, the need for treatment and treatment starting time are controversial. We restate in our article that fractionated stereotactic radiotherapy improves visual function. We further search for prognostic factors which might provide valuable additional and independent information on when to start treatment. We reveal that the visual acuity is a prognostic factor for the outcome of stereotactic therapy for ONSM and promote it as a biomarker for the decision for treatment initiation.

Abstract

Objective: To evaluate prognostic factors for a favorable outcome (improvement of the visual acuity or visual fields) after fractionated stereotactic radiotherapy (fSRT) of optic nerve sheath meningioma (ONSM). Methods: We performed a database search for ONSM treatments during the period from April 2008 to September 2019 in the prospective database for stereotactic radiosurgery/radiotherapy (SRS/SRT) of the Robert Janker Clinic Bonn (Department of Radiotherapy) and performed a literature review and meta-analysis of published data on ONSM between 2010 and 2019. Ophthalmic status before and after treatment was evaluated and the collective was dichotomized into two groups: functional improvement (FI; improvement of either visual acuity or visual fields) and non functional improvement (NFI; with stable or deteriorating visual acuity or visual fields). The two groups were compared regarding different variables: pretreatment visual acuity, age, gender, gross tumor volume (GTV), follow up (FU) time, tumor localization, and maximal retina dose. Results: Overall, 13 stereotactic radiotherapies were performed for ONSM (12 × fSRT, 1 × SRS). Mean follow up was 3 years (range: 1–5 years). The total dose was 50.4 Gy (5 × 1.8 Gy/week) in 12 patients treated with fSRT and 1 × 14 Gy in one SRS case. Mean GTV was 1.13 ccm (range: 0.44–2.20 ccm). During follow up, all tumors were stable or showed shrinkage of tumor volume (100% tumor control), no adverse events were observed, 53% of the patients achieved either better visual acuity or visual fields. Pretreatment visual acuity was significantly different between the FI and the NFI group (0.17 vs. 0.63, p = 0.03) in our series and in the meta analysis (p < 0.01). Moreover, shorter FU time and lower retinal dose were significantly linked (p < 0.05 and p < 0.01, respectively) with a better outcome in the meta-analysis but not in our patient cohort. Intracranial tumor localization, gender, and age were not significantly different between the two outcome groups. Conclusion: FSRT for ONSM achieves in over 50% of cases an improvement of the ophthalmic status with low morbidity and excellent tumor control in our series and the meta analysis. Patients with a favorable outcome had in all analysis a significantly higher visual acuity before treatment start. Therefore, we advocate using fSRT as early as possible before vision deterioration occurs.

Optic nerve sheath meningioma

PURPOSE OF REVIEW

Optic nerve sheath meningiomas (ONSMs) are rare benign tumors of the anterior visual pathway which present with slowly progressive and painless vision loss and account for approximately 2% of all orbital tumors. This article provides an overview as well as an update on the ONSMs with regards to cause, epidemiology, clinical presentation, diagnosis, and management in adults and pediatric population.

RECENT FINDINGS

The clinical presentation and prognosis of ONSMs can vary and largely depend on the location of tumor as well as the histologic type. Overall, the diagnosis is based on clinical presentation, examination, and neuroimaging findings. Nevertheless, delays in diagnosis or misdiagnosis are not uncommon and can result in higher morbidity rates. Recent advances in diagnostic as well as more effective and less-invasive treatment options are discussed in this review.

SUMMARY

ONSMs are a rare cause of slowly progressive and inexorable visual loss. Although ONSM diagnosis depends on the characteristic clinical and radiologic findings, prompt diagnosis, and appropriate management is critical for favorable visual outcomes. Thus, current focus is optimizing diagnostic as well-treatment methods for patients with ONSMs.

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.

Prognostic factors in the surgical treatment of intracanalicular primary optic nerve sheath meningiomas

OBJECTIVE

Although meningiomas frequently involve the optic nerve, primary optic nerve sheath meningiomas (ONSMs) are rare, accounting for only 1% of all meningiomas. Given the high risk of vision loss with these tumors, surgical intervention is seldom considered, and radiation or observation is commonly applied. Here, the authors describe the visual outcomes for a series of patients who were treated with surgery aiming at maximal tumor resection and highlight their prognostic factors.

METHODS

The authors retrospectively analyzed the data for 8 patients with intracanalicular ONSMs who had been surgically treated by the senior author (O.A.) between 1998 and 2016. Meningiomas extending into the optic canal from the intracranial cavity (i.e., clinoid, sphenoid wing, tuberculum sellae, diaphragma sellae) were excluded. Diagnosis was based on ophthalmological, radiological, and intraoperative findings, which were confirmed by the typical histological findings. Preoperative, postoperative, and follow-up visual assessments were performed by neuro-ophthalmologists in all cases.

RESULTS

The patients included 7 females and 1 male. The mean age at diagnosis was 45.1 years (range 25.0-70.0 years). Mean duration of follow-up was 38.9 months (range 3.0-88.0 months). All patients reported visual complaints, and all had objective evidence of optic nerve dysfunction. Their evaluation included visual field, visual acuity, funduscopy, and retinal fiber thickness. Total resection was obtained in 4 cases. Comparing preoperative and postoperative visual function revealed that 4 patients had improvement at the last follow-up, 1 patient had stable vision, and 3 patients had decreased function but none had total vision loss. All patients with good preoperative visual acuity maintained this status following surgical treatment. There was no surgical mortality or infection. Operative complications included binocular diplopia in 4 patients, which remitted spontaneously.

CONCLUSIONS

Surgery can play a beneficial role in the primary treatment of ONSM, especially lesions located in the posterior third of the nerve. Total removal can be achieved with vision preservation or improvement, without major surgical complications, especially at early stages of the disease. Patients with good preoperative vision and CSF flow in the optic sheath have better chances of a favorable outcome than those with poor vision.

Optic nerve sheath meningiomas: prevalence, impact, and management strategies

Optic nerve sheath meningiomas are rare benign neoplasms of the meninges surrounding the optic nerve. They are a significant cause of morbidity. While the mortality rate is practically zero, these tumors can blind or disfigure patients. Given that the clinical course can be variable, and treatment has the capacity to cause morbidity itself, the management of these patients can be difficult. We review the literature to discuss the prevalence of optic nerve sheath meningiomas, the association with neurofibromatosis type 2, natural history, and management options and strategies.

Revisiting the dose constraints for head and neck OARs in the current era of IMRT

Head and neck cancer poses a particular challenge in radiation therapy, whilst being an effective treatment modality it requires very high doses of radiation to provide effective therapy. This is further complicated by the fact that the head and neck region contains a large number of radiosensitive tissues, often resulting in patients experiencing debilitating normal tissue complications. In the era of intensity-modulated radiation therapy (IMRT) treatments can be delivered using non-uniform dose distributions selectively aimed at reducing the dose to critical organs-at-risk while still adequately covering the tumor target. Dose-volume constraints for the different risk organs play a vital role in one's ability to devise the best IMRT treatment plan for a head and neck cancer patient. To this end, it is pivotal to have access to the latest and most relevant dose constraints available and as such the goal of this review is to provide a summary of suggested dose-volume constraints for head and neck cancer RT that have been published after the QUANTEC reports were made available in early 2010.

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.

Optic Nerve Sheath Meningioma: Preliminary Analysis of the Role of Radiation Therapy

Background

The purpose of this study was to evaluate the treatment outcome of our optic nerve sheath meningioma (ONSM) case series in terms of preventing tumor growth and preserving vision in ONSM patients.

Methods

Between July 2003 and March 2015, 1,398 patients with intracranial meningioma were diagnosed at Seoul National University Bundang Hospital. Among them, only 13 patients (0.93%) were diagnosed with ONSM and enrolled in the present study. Tumor volume changes of ONSM patients and their visual acuity were evaluated before and after treatments.

Results

The median follow-up time was 50 months (range, 12–133 months). Visual acuity was evaluated in 12 of 13 patients, and visual acuity was found to be preserved in 9 of 12 patients (75%). Tumor volume was reduced in all patients. The tumor control rate was 100% in the present study. The difference in tumor volume between pretreatment and last follow-up was statistically significant (p=0.015).

Conclusion

Intensity-modulated radiotherapy (IMRT) and gamma knife radiosurgery (GKS) could maintain visual acuity and stabilize tumor volume in ONSM patients, suggesting that IMRT and GKS may be effective therapies for ONSM. However, which treatment is the more effective modality must be confirmed by prospective studies and longer-term follow-up.

Rapid recovery of vision following early intervention with fractionated stereotactic radiotherapy for optic nerve sheath meningioma

Purpose

To report the outcomes of early intervention with fractionated stereotactic radiotherapy (FSRT) in a patient with primary optic nerve sheath meningioma (ONSM).

Patient and methods

A male patient in his early 40s underwent 5-beam FSRT at a prescribed dose of 50 Gy in 25 fractions over 35 days. The patient had an 11-month history of progressive visual impairment at the time of FSRT.

Results

On day 14 of treatment, the patient reported early improvement in his vision. Two weeks after the completion of FSRT, his left eye visual acuity and field recovered completely. However, the tumor regressed only slightly in the 2 years of follow-up.

Conclusion

Early intervention with FSRT for optic nerve sheath meningioma resulted in a rapid response and complete improvement of visual impairment.

Systematic Review of Normal Tissue Complication Models Relevant to Standard Fractionation Radiation Therapy of the Head and Neck Region Published After the QUANTEC Reports

There has recently been an increasing interest in model-based evaluation and comparison of different treatment options in radiation oncology studies. This is partly driven by the considerable technical advancements in radiation therapy of the last decade, leaving radiation oncologists with a multitude of options to consider. In lieu of randomized trials comparing all of these different treatment options for varying indications, which is unfeasible, treatment evaluations based on normal tissue complication probability (NTCP) models offer a practical alternative. The Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) effort, culminating in a number of reports published in 2010, provided a basis for many of the since-implemented dose-response models and dose-volume constraints and was a key component for model-based treatment evaluations. Given that 7 years have passed since the QUANTEC publications and that patient-reported outcomes have emerged as an important consideration in recent years, an updated summary of the published radiation dose-response literature, which includes a focus on patient-reported quality of life outcomes, is warranted. Here we provide a systematic review of quantitative dose-response models published after January 1, 2010 for endpoints relevant to radiation therapy for head and neck cancer, because these patients are typically at risk for a variety of treatment-induced normal tissue complications.

Surgical Resection of an Optic Nerve Sheath Meningioma: Relevance of Endoscopic Endonasal Approaches to the Optic Canal

Optic nerve sheath meningiomas (ONSMs) account for less than 2% of meningiomas and 1.7% of orbital tumors. Although rare, the management of these tumors is important as unilateral blindness often results in untreated cases. Radiotherapy has emerged as the preferred treatment. However, therapies for ONSMs are controversial due to the variable natural history of the disease and limitations of surgical and radiotherapy options. A 60-year-old woman presented with monocular left diminished color perception and blurred vision. Magnetic resonance imaging demonstrated a homogenously enhancing 5-mm left optic nerve mass with evidence of nerve compression. Conservative management was advised. However, 1 month after diagnosis her visual acuity deteriorated further. Because of the small focal location of the tumor within the optic canal, surgery was considered. Given the tumor's location inferomedial to the optic nerve, an endoscopic endonasal approach to the optic canal was performed. This patient recovered fully with resolution of visual symptoms immediately following surgery. Postoperative imaging 24 hours after surgery demonstrated gross total resection of the tumor; 1 year postoperatively the patient has a normal ophthalmologic examination. This report highlights the value of endoscopic endonasal approaches in the management of select optic canal pathology, otherwise inaccessible via transcranial approaches.

Optic Nerve

Optic nerve diseases arise from many different etiologies including inflammatory, neoplastic, genetic, infectious, ischemic, and idiopathic. Understanding some of the characteristics of the most common optic neuropathies along with therapeutic approaches to these diseases is helpful in designing recommendations for individual patients. Although many optic neuropathies have no specific treatment, some do, and it is those potentially treatable or preventable conditions which need to be recognized in order to help patients regain their sight or develop a better understanding of their own prognosis. In this chapter several diseases are discussed including idiopathic intracranial hypertension, optic neuritis, ischemic optic neuropathies, hereditary optic neuropathies, trauma, and primary tumors of the optic nerve. For each condition there is a presentation of the signs and symptoms of the disease, in some conditions the evaluation and diagnostic criteria are highlighted, and where possible, current therapy or past trials are discussed.

Fractionated radiotherapy and radiosurgery of intracranial meningiomas

This review focuses on the role of radiosurgery and fractionated radiotherapy in the management of intracranial meningiomas, which are the most common benign intracranial tumors. Whenever feasible, surgery remains a cornerstone of treatment in effective health care treatment where modern radiotherapy plays an important role. Irradiation can be proposed as first-line treatment, as adjuvant treatment, or as a second-line treatment after recurrence. Stereotactic radiosurgery consists of delivering, a high-dose of radiation with high precision, to the tumor in a single-fraction with a minimal exposure of surrounding healthy tissue. Stereotactic radiosurgery, especially with the gamma knife technique, has reached a high level of success for the treatment of intracranial meningiomas with excellent local control and low morbidity. However, stereotactic radiosurgery is limited by tumor size,<3-4cm, and location, i.e. reasonable distance from the organs at risk. Fractionated radiation therapy is an interesting alternative (5 to 6weeks treatment time) for large inoperable tumors. The results of fractionated radiation therapy seem encouraging as regards both local control and morbidity although long-term prospective studies are still needed.

[Apropos of 5 cases of optic nerve tumors diagnosed during a 6-year-period]

INTRODUCTION

Optic nerve tumors are uncommon and rarely described. By way of five patients treated at the University Hospital of Clermont-Ferrand, France, over a six-year-period, we discuss their clinical and radiological characteristics, their treatment and their course.

OBSERVATIONS

We report two cases of optic nerve glioma in small children, two cases of optic nerve sheath meningioma and a 57-year-old patient treated for lung cancer with an optic nerve metastasis and choroidal and brain metastases. The diagnosis was confirmed by imaging in all patients and histologically for the cases of optic nerve glioma.

RESULTS

The children with glioma were exclusively treated with chemotherapy, the two women with meningioma exclusively with radiation therapy, and the man with the optic nerve metastasis by chemotherapy and radiotherapy. The tumors were stabilized in all cases except for a progression in one case of glioma, one year after treatment.

DISCUSSION

Gliomas and meningiomas are the most frequent tumors; other tumors are rare. Through a literature review and many illustrations, we discuss epidemiologic, clinical and radiologic characteristics, treatment and course of these uncommon tumors.

CONCLUSION

The diagnosis of optic nerve tumors must be considered in cases of anterior or posterior progressive optic neuropathy. Treatment must be a compromise between effective treatment of the tumor and preservation of visual function. Decisions are made through multidisciplinary consultations, in which the role of the ophthalmologist is crucial for the diagnosis and success of the treatment.

[Results of fractionated targeted proton beam therapy in the treatment of primary optic nerve sheath meningioma]

INTRODUCTION

Optic nerve sheath meningioma (ONSM) is a common benign neoplasm arising from the arachnoid tissue encapsulating the optic nerve and affects mainly middle aged women. It is a slow-growing tumor for which there is still no consensus on treatment.

PURPOSE

To evaluate the safety and efficacy of fractionated targeted proton beam therapy (PBT) in the treatment of ONSM and to define its role in the treatment of these tumors.

METHODS AND MATERIALS

We performed a retrospective analysis of 15 patients (13 women and 2 men), mean age 41.8 years, presenting with primary ONSM, followed at the Fondation Ophtalmologique Adolphe de Rothschild (Paris) between September 2006 and August 2013. After a multidisciplinary consultation, all were treated with PBT at a total dose of 52.2 Gy Eco, in fractions of 1.8 Gy Eco, at the Institut Curie (Paris). Patients underwent standardized follow-up including ophthalmologic examinations, visual field testing and imaging every 6 months. Study parameters were post-treatment visual acuity, tumor size on MRI, and treatment side effects

RESULTS

We separated the patients into 3 distinct groups: patients treated by PBT after an observation period (4/15), patients treated by PBT after primary surgery (5/15) and patients treated by PBT as primary treatment (6/15). Visual acuity improved in 3 cases, deteriorated in 1 and remained stable in 11 cases. Tumor size on MRI remained stable in 100 % of cases following PBT. No serious adverse effects were recorded after a mean follow-up of 22.4 months (8-79 months).

CONCLUSION

Our experience confirms the efficacy and the safety of proton beam therapy in patients with ONSM. PBT presents a promising alternative to surgery and conventional radiotherapy in the treatment of the MGNO. It seems to be effective in controlling tumor size and stabilizing visual function, at the cost of very low toxicity. Additional studies are needed to accurately determine the decision-making criteria and the ideal timing of this treatment.

Optic nerve sheath meningioma: a case report with 15-year follow-up

Meningiomas are benign neoplastic lesions of arachnoidal cells of the meninges. These tumors may arise wherever meninges exists, such as in the nasal cavity, paranasal sinuses, middle ear, and mediastinum. Optic nerve sheath meningiomas (ONSMs) are usually unilateral and occur predominantly in middle-aged females, although they may be present at any age. We present a case of a 55-year-old female with ONSM diagnosed when she was 40 years old. Diagnosis and follow-up was based on the clinical picture, CT orbit scan, and magnetic resonance imaging.

Radiotherapy for optic nerve sheath meningioma: a case for earlier intervention?

AIMS

To assess tumour control, visual outcomes and toxicity after radiotherapy for all patients with optic nerve sheath meningiomas (ONSM) treated by a single radiation oncologist at a single institution over a 15 year period. To explore potential predictors of outcomes.

MATERIALS AND METHODS

All patients underwent ophthalmological and radiological assessments before radiotherapy. These were repeated at regular intervals after treatment. A retrospective analysis of clinical, dosimetric and radiological data was carried out. Patients with useful vision before radiotherapy were divided into two groups - those with maintained or improved vision and those with a deterioration in vision. The groups were compared using the Mann-Whitney U-test with regard to eight potential predictors of outcome.

RESULTS

Seventeen patients with 18 ONSM were treated with fractionated radiotherapy (46.8-55.8 Gy in 26-31 fractions). No evaluable tumours grew after treatment: control rate 100% (95% confidence interval 82-100%). Using the most common definition of visual function described in the literature, vision was maintained or improved in 89% (95% confidence interval 67-97%) of cases. In those with useful vision before treatment (13 evaluable eyes), visual acuity was maintained or improved in eight (62%, 95% confidence interval 36-82%). There was a suggestion that the time from the onset of symptoms to radiotherapy may influence outcome. Those with stable or better visual acuity after radiotherapy had been observed for a shorter time compared with those who had worse visual acuity (median of 18 months versus 62 months). Acute and late toxicity from radiotherapy was manageable.

CONCLUSION

Radiotherapy is an extremely effective modality in arresting the growth of ONSM. A longer time from symptom onset to the start of radiotherapy may predict for poorer outcomes.

Neuro-ophthalmology Annual Review

PURPOSE

To provide a clinical update of the neuro-ophthalmology literature over the last twelve months.

DESIGN

This is an annual review of current literature from August 1, 2011 to August 1, 2012.

METHODS

The authors conducted a one year English language neuro-ophthalmology literature search using PubMed from August 1, 2011 to August 1, 2012 using the following search terms: pupil abnormalities, eye movements, diseases of muscle and musculoskeletal junction, optic nerve disorders, optic neuritis and multiple sclerosis, chiasm and posterior primary visual pathway lesions, increased intracranial pressure and related entities, tumors (e.g., meningioma) and aneurysm affecting the visual pathways, vascular diseases, higher visual functions, advances in neuroimaging, and miscellaneous topics in neuro-ophthalmology. The authors included original articles, review articles, and case reports, which revealed the new aspects and updates in neuro-ophthalmology. Letters to the editor, unpublished work, and abstracts were not included in this annual literature review. We propose to update the practicing clinical ophthalmologist on the most clinically relevant literature from the past year. However, this review is not meant to be all-inclusive and highlights only the literature most applicable to the practicing clinical ophthalmologist.

RESULTS

We reviewed the literature over the past year in neuro-ophthalmology of potential interest and relevance to the comprehensive ophthalmologist.

CONCLUSION

This annual review provides a brief update on a number of neuroophthalmic conditions that might be of interest to the practicing clinical ophthalmologist.