Fractionated stereotactic radiation therapy for orbital optic nerve sheath meningioma - a single institution experience and a short review of the literature

Stereotactic Radiation Therapy for Brain Metastases: Factors Affecting Outcomes and Radiation Necrosis

Stereotactic radiation therapy (SRT) is a proven effective treatment for brain metastases (BM); however, symptomatic radiation necrosis (RN) is a late effect that may impact on patient’s quality of life. The aim of our study was to retrospectively evaluate survival outcomes and characterize the occurrence of RN in a cohort of BM patients treated with ablative SRT at Federico II University Hospital. Clinical and dosimetric factors of 87 patients bearing a total of 220 BMs treated with SRT from 2016 to 2022 were analyzed. Among them, 46 patients with 127 BMs having clinical and MRI follow-up (FUP) ≥ 6 months were selected for RN evaluation. Dosimetric parameters of the uninvolved brain (brain without GTV) were extracted. The crude local control was 91% with neither clinical factors nor prescription dose correlating with local failure (LF). At a median FUP of 9 (1–68) months, the estimated median overall survival (OS), progression-free survival (PFS), and brain progression-free survival (bPFS) were 16, 6, and 9 months, respectively. The estimated OS rates at 1 and 3 years were 59.8% and 18.3%, respectively; bPFS at 1 and 3 years was 29.9% and 13.5%, respectively; PFS at 1 and 3 years was 15.7% and 0%, respectively; and local failure-free survival (LFFS) at 1 and 3 years was 87.2% and 83.8%, respectively. Extracranial disease status was an independent factor related to OS. Fourteen (30%) patients manifested RN. At multivariate analysis, adenocarcinoma histology, left location, and absence of chemotherapy were confirmed as independent risk factors for any-grade RN. Nine (20%) patients developed symptomatic (G2) RN, which improved or stabilized after 1–16 months of steroid therapy. With prompt recognition and, when necessary, medical therapy, RN radiological and clinical amelioration can be obtained.

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.

Risks and Benefits of Surgical Excision of Orbital Cavernous Venous Malformations (So-Called Cavernous Hemangioma): Factors Influencing the Outcome

PURPOSE

To assess risks and benefits associated with surgical excision of orbital cavernous venous malformation and analyze factors influencing the outcome.

METHODS

Design: cohort study. Participants: 164 consecutive patients undergoing surgical removal of orbital cavernous venous malformation. Intervention: lateral or anterior orbitotomy. Outcome measures: visual acuity, visual field, pupillary function, ocular motility, and fundus examination. Influence of the mass volume and tumor location on the outcome was evaluated. The threshold value and risk group for the volume were evaluated using the receiver operating characteristic analysis; 8 orbital different quadrants, extraconal/intraconal position, and orbital apex extension were considered as variables to evaluate the location.

RESULTS

Postoperatively overall visual acuity (p = 0.0084), visual field (p < 0.0001), diplopia (p < 0.0001), proptosis (p < 0.0001), ocular motility (p = 0.02), ptosis (p = 0.033), choroidal fold (p < 0.0001), disk edema (p = 0.0004) were significantly improved. The commonest location was the lateral quadrant (28%). Choroidal folds were associated with tumor greater than 1100 mm3 (p = 0.001). Visual loss occurred in 2 patients (1.2%) and tonic pupil in 5 (3%,) Visual deterioration was associated with the apical extension (p = 0.001). Pupil efferent defect was associated with lateral quadrant location (p = 0.011) and apical extension (p = 0.05).

CONCLUSIONS

Surgical removal of orbital cavernous venous malformation is a useful treatment modality, particularly for large size tumors. Removal of cavernous venous malformations located at the lateral aspect of the orbit carries an increased risk of permanent tonic pupil. Postoperative blindness is rarely seen and is often associated with the apical extension. Tailoring the surgical approach, depending on the relative position to the optic nerve, may have an important bearing on outcome.

Effectiveness and Safety of Robotic Radiosurgery for Optic Nerve Sheath Meningiomas: A Single Institution Series

Simple Summary

Optic nerve sheath meningiomas (ONSM) are a rare subtype of meningioma. Only four retrospective studies with 3–21 patients have been published on the treatment of ONSM by radiosurgery. This study represents the largest published series on robotic radiosurgery to date, treating 25 patients with 27 ONSM lesions. Furthermore, hypofractionated radiosurgical treatment proves to be a safe alternative to surgery and fractionated stereotactic radiation with an overall local tumor control rate of 96.0% and stable or improved visual acuity in 90.0% and 10.0% of patients, respectively. We believe that our study makes a significant contribution to the literature, as our results indicate that robotic radiosurgery is a safe and effective treatment for the management of ONSM and offers a potential treatment option that would improve patient care and clinical outcomes.

Abstract

The role of robotic radiosurgery (RRS) in the treatment of optic nerve sheath meningiomas (ONSM) remains controversial and it is only performed in specialized institutions due to tight dose constraints. We evaluated the effectiveness and safety of RRS in the management of ONSM. Twenty-five patients with 27 ONSM lesions who underwent RRS using the Cyberknife (CK) system were retrospectively analyzed (median age, 47.9 years; 84.0% women). Multisession RRS was used with 4–5 fractions with a cumulative dose of 20.0–25.0 Gy in 84.0% of patients and a single fraction at a dose of 14.0–15.0 Gy in 16% of patients. Prior to RRS, seven (28%) patients experienced blindness on the lesion side. In those patients with preserved vision prior to radiosurgery, the visual acuity remained the same in 90.0% and improved in 10.0% of the patients. Overall local tumor control was 96.0% (mean follow-up period; 37.4 ± 27.2 months). Neither patient age, previous surgery, or the period from the initial diagnosis to RRS showed a dependency on visual acuity before or after radiosurgery. RRS is a safe and effective treatment for the management of ONSM. Hypofractionation of radiosurgery in patients with preserved vision before CK treatment results in stable or improved vision.

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.

Image-Guided Multisession Radiosurgery of Skull Base Meningiomas

Simple Summary

Stereotactic radiosurgery has changed the landscape of treatment for skull base meningiomas. Lesions encasing or compressing radiosensitive structures are considered not suitable for single session stereotactic radiosurgery because of the high risk of side effects. Multisession stereotactic radiosurgery can reduce these risks, allowing for normal tissue repair between fractions, while delivering a high dose per fraction. The aim of this study is to validate the role of multi-session stereotactic radiosurgery in the treatment of skull base meningiomas, through a retrospective analysis of 156 patients affected by skull base meningioma, treated at the University of Messina between 2008 and 2018. Our study suggests that multisession stereotactic radiosurgery represents a safe and effective profile in the treatment of skull base meningioma, providing a satisfactory local control and a low toxicity rate, together with patient comfort from a frameless procedure.

Abstract

Background: The efficacy of single-session stereotactic radiosurgery (sSRS) for the treatment of intracranial meningioma is widely recognized. However, sSRS is not always feasible in cases of large tumors and those lying close to critically radiation-sensitive structures. When surgery is not recommended, multi-session stereotactic radiosurgery (mSRS) can be applied. Even so, the efficacy and best treatment schedule of mSRS are not yet established. The aim of this study is to validate the role of mSRS in the treatment of skull base meningiomas. Methods: A retrospective analysis of patients with skull base meningiomas treated with mSRS (two to five fractions) at the University of Messina, Italy, from 2008 to 2018, was conducted. Results: 156 patients met the inclusion criteria. The median follow-up period was 36.2 ± 29.3 months. Progression-free survival at 2-, 5-, and 10- years was 95%, 90%, and 80.8%, respectively. There were no new visual or motor deficits, nor cranial nerves impairments, excluding trigeminal neuralgia, which was reported by 5.7% of patients. One patient reported carotid occlusion and one developed brain edema. Conclusion: Multisession radiosurgery is an effective approach for skull base meningiomas. The long-term control is comparable to that obtained with conventionally-fractionated radiotherapy, while the toxicity rate is very limited.

Stage IV Small Lymphocytic Lymphoma Presenting with Unilateral Vision Loss

Small lymphocytic lymphoma (SLL) is a manifestation of chronic lymphocytic leukemia (CLL) in which malignant B-cell lymphocytes accumulate in the lymph nodes or bone marrow. In this report, we describe the medical course of a patient diagnosed with stage IV small cell lymphocytic lymphoma, who presented to the emergency room with acute neurologic manifestations of SLL.

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.

Normofractionated stereotactic radiotherapy versus CyberKnife-based hypofractionation in skull base meningioma: a German and Italian pooled cohort analysis

Background

This retrospective German and Italian multicenter analysis aimed to compare the role of normofractionated stereotactic radiotherapy (nFSRT) to CyberKnife-based hypofractionated stereotactic radiotherapy (CK-hFSRT) for skull base meningiomas.

Methods

Overall, 341 patients across three centers were treated with either nFSRT or CK-hFSRT for skull base meningioma. Treatment planning was based on computed tomography (CT) and magnetic resonance imaging (MRI) following institutional guidelines. Most nFSRT patients received 33 × 1.8 Gy, and most CK-hFSRT patients received 5 × 5 Gy. The median follow-up time was 36 months (range: 1–232 months).

Results

In the CK-hFSRT group, the 1-, 3-, and 10-year local control (LC) rates were 99.4, 96.8, and 80.3%, respectively. In the nFSRT group, the 1-, 3-, and 10-year LC rates were 100, 99, and 79.1%, respectively. There were no significant differences in LC rates between the nFSRT and CK-hFSRT groups (p = 0.56, hazard ratio = 0.76, 95% confidence interval, 0.3–1.9). In the CK-hFSRT group, only one case (0.49%) of severe toxicity (CTCAE 4.0 ≥ 3) was observed. In the nFSRT group, three cases (2.1%) of grade III toxicity were observed.

Conclusion

This analysis of pooled data from three centers showed excellent LC and low side effect rates for patients treated with CK-hFSRT or nFSRT. The efficacy, safety, and convenience of a shortened treatment period provide a compelling case for the use of CK-hFSRT in patients with moderate size skull base meningioma and provided that OAR constraints are met.

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.

Technological evolution of radiation treatment: Implications for clinical applications

The contemporary approach to the management of a cancer patient requires an "ab initio" involvement of different medical domains in order to correctly design an individual patient's pathway toward cure. With new therapeutic tools in every medical field developing faster than ever before the patient care outcomes can be achieved if all surgical, drug, and radiation options are considered in the design of the appropriate therapeutic strategy for a given patient. Radiation therapy (RT) is a clinical discipline in which experts from different fields continuously interact in order to manage the multistep process of the radiation treatment. RT is found to be an appropriate intervention for diverse indications in about 50% of cancer patients during the course of their disease. Technologies are essential in dealing with the complexity of RT treatments and for driving the increasingly sophisticated RT approaches becoming available for the treatment of Cancer. High conformal techniques, namely intensity modulated or volumetric modulated arc techniques, ablative techniques (Stereotactic Radiotherapy and Stereotactic Radiosurgery), particle therapy (proton or carbon ion therapy) allow for success in treating irregularly shaped or critically located targets and for the sharpness of the dose fall-off outside the target. The advanced on-board imaging, including real-time position management systems, makes possible image-guided radiation treatment that results in substantial margin reduction and, in select cases, implementation of an adaptive approach. The therapeutic gains of modern RT are also due in part to the enhanced anticancer activity obtained by coadministering RT with chemotherapy, targeted molecules, and currently immune checkpoints inhibitors. These main clinically relevant steps forward in Radiation Oncology represent a change of gear in the field that may have a profound impact on the management of cancer patients.

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.

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.

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.

Total recovery of optic nerve sheath meningioma

We reported the case of a 43-year-old woman with a rapid progressive visual loss. The diagnosis of primary optic nerve sheath meningioma was made thanks to atypia evolution, clinical and radiological findings. The patient was treated with an intensity-modulated radiotherapy of 50.4 Gy in 28 fractions 2 months after the diagnosis. Visual acuity and visual field were completely recovered after 2 years of follow-up. No late side effects of irradiation were recorded.

An unusual radiological presentation of optic nerve sheath meningioma

Our report describes an unusual radiological presentation of optic nerve sheath meningioma. The classic radiological appearance of optic nerve thickening with enhancement and calcification within the tumor was not seen; instead, an elongating gadolinium enhancing band-like area adjacent to the superomedial aspect of the left optic nerve sheath was identified. The diagnosis was confirmed on histopathology. Our report adds to the spectrum of presentations of this relatively common clinical entity.

Pediatric Optic Nerve Meningioma: Diagnostic and Therapeutic Challenges

A 13-year-old female presented with left unilateral proptosis, blurry vision, and diplopia. Clinical examination showed left sided visual acuity of 20/50, limited extraocular movement, 5-mm proptosis, and optic disc edema. CT and MRI displayed a large, intraconal, well-demarcated soft tissue mass with inferotemporal displacement of the optic nerve. The imaging appearance was unusual and diagnosis remained uncertain. Histopathologic analysis of the biopsy specimen confirmed the diagnosis of atypical syncytial meningioma. The tumor cells were positive for both androgen and progesterone receptors and the Ki67 stain was positive (proliferation index of 8%). The patient was treated with proton beam radiation therapy (total dose 50.4 GyE) that suppressed tumor growth and has preserved visual acuity to date (20/40). Differential diagnosis and approaches to therapy are explored.

[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.

Genetic profiling by single-nucleotide polymorphism-based array analysis defines three distinct subtypes of orbital meningioma

Orbital meningiomas can be classified as primary optic nerve sheath (ON) meningiomas, primary intraorbital ectopic (Ob) meningiomas and spheno-orbital (Sph-Ob) meningiomas based on anatomic site. Single-nucleotide polymorphism (SNP)-based array analysis with the Illumina 300K platform was performed on formalin-fixed, paraffin-embedded tissue from 19 orbital meningiomas (5 ON, 4 Ob and 10 Sph-Ob meningiomas). Tumors were World Health Organization (WHO) grade I except for two grade II meningiomas, and one was NF2-associated. We found genomic alterations in 68% (13 of 19) of orbital meningiomas. Sph-Ob tumors frequently exhibited monosomy 22/22q loss (70%; 7/10) and deletion of chromosome 1p, 6q and 19p (50% each; 5/10). Among genetic alterations, loss of chromosome 1p and 6q were more frequent in clinically progressive tumors. Chromosome 22q loss also was detected in the majority of Ob meningiomas (75%; 3/4) but was infrequent in ON meningiomas (20%; 1/5). In general, Ob tumors had fewer chromosome alterations than Sph-Ob and ON tumors. Unlike Sph-Ob meningiomas, most of the Ob and ON meningiomas did not progress even after incomplete excision, although follow-up was limited in some cases. Our study suggests that ON, Ob and Sph-Ob meningiomas are three molecularly distinct entities. Our results also suggest that molecular subclassification may have prognostic implications.

[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.

Percutaneous fiducial marker placement under CT fluoroscopic guidance for stereotactic body radiotherapy of the lung: an initial experience

The aim of this study is to describe our initial experience with the VISICOIL, which is the first percutaneous fiducial marker approved for stereotactic body radiotherapy in Japan, and to evaluate its technical and clinical efficacy, and safety. Eight patients underwent this procedure under CT fluoroscopic guidance. One patient had two tumors, so the total number of procedures was nine. We evaluated the technical and clinical success rates of the procedure and the frequencies of complications. Technical success was defined as when the fiducial marker could be placed at the target site, and clinical success was defined as when stereotactic body radiotherapy could be performed without the marker dropping out of position. The technical success rate was 78% (7/9). In one of the two failed cases, we aimed to place the marker inside the tumor, but misplaced it beside the tumor. In the other failed case, we successfully placed the marker beside the tumor as planned; however, the marker migrated to near the pleura after the patient stopped holding their breath. None of the markers dropped out of place, so the clinical success rate was 100% (9/9). The complication rates were as follows: pneumothorax: 56% (5/9), pneumothorax necessitating chest tube placement: 44% (4/9), focal intrapulmonary hemorrhaging: 67% (6/9), hemoptysis: 11% (1/9), mild hemothorax 11% (1/9), air embolism 0% (0/9), and death 0% (0/9). In conclusion, this new percutaneous fiducial marker appears to be useful for stereotactic body radiotherapy due to its good stability.

Fractionated stereotactic conformal radiotherapy for optic nerve sheath meningiomas

AIMS

To assess visual outcome, tumour control and treatment-related morbidity in patients with optic nerve sheath meningiomas (ONSMs) treated with fractionated stereotactic radiotherapy (FSRT).

PATIENTS AND METHODS

A retrospective analysis of 45 patients (13 men and 32 women, median age 46 years) with ONSMs (51 optic nerves involved) treated in a single institution between 1997 and 2010 was carried out. FSRT was delivered to a dose of 50 Gy in 30 or 33 fractions as primary treatment in 39 patients and after surgery in six patients.

RESULTS

At a median follow-up of 30 months (range 1-13 years), the tumour control in 41 evaluable patients (four were lost to follow-up) was 100% at 5 years with no subsequent local or distant recurrence. Of the 46 evaluable optic nerves treated, 41 had residual vision (38 with impaired vision) before radiotherapy and five were blind in one eye. There was no recovery of vision in any of the blind eyes. Of 41 optic nerves with residual vision, 13 had improvement, 24 remained stable and four deteriorated; two patients (4%) developed radiation retinopathy. One patient developed a central retinal artery occlusion in the untreated eye 10 years after treatment.

CONCLUSION

FSRT is highly effective at controlling the growth of ONSMs with improvement or stabilisation of visual deficit in 89% of the optic nerves retaining some vision, albeit with a small risk of radiation-induced retinopathy. The results support the use of FSRT as an effective approach in the management of ONSM. The lack of functional benefit in patients with severe visual impairment would argue for earlier institution of treatment before complete visual loss is established.

Radiobiological evaluation of the radiation dose as used in high-precision radiotherapy: effect of prolonged delivery time and applicability of the linear-quadratic model

Since the dose delivery pattern in high-precision radiotherapy is different from that in conventional radiation, radiobiological assessment of the physical dose used in stereotactic irradiation and intensity-modulated radiotherapy has become necessary. In these treatments, the daily dose is usually given intermittently over a time longer than that used in conventional radiotherapy. During prolonged radiation delivery, sublethal damage repair takes place, leading to the decreased effect of radiation. This phenomenon is almost universarily observed in vitro. In in vivo tumors, however, this decrease in effect can be counterbalanced by rapid reoxygenation, which has been demonstrated in a laboratory study. Studies on reoxygenation in human tumors are warranted to better evaluate the influence of prolonged radiation delivery. Another issue related to radiosurgery and hypofractionated stereotactic radiotherapy is the mathematical model for dose evaluation and conversion. Many clinicians use the linear-quadratic (LQ) model and biologically effective dose (BED) to estimate the effects of various radiation schedules, but it has been suggested that the LQ model is not applicable to high doses per fraction. Recent experimental studies verified the inadequacy of the LQ model in converting hypofractionated doses into single doses. The LQ model overestimates the effect of high fractional doses of radiation. BED is particularly incorrect when it is used for tumor responses in vivo, since it does not take reoxygenation into account. For normal tissue responses, improved models have been proposed, but, for in vivo tumor responses, the currently available models are not satisfactory, and better ones should be proposed in future studies.