Stereotactic radiosurgery in the treatment of parasellar meningiomas: long-term volumetric evaluation

Extended Long-Term Outcome After Conservative Decompressive Microsurgery and Routine Adjuvant Fractionated Stereotactic Radiotherapy for Symptomatic Cavernous Sinus Meningiomas

BACKGROUND AND OBJECTIVES

Cavernous sinus meningiomas (CSM) pose one of the most difficult to treat subgroup of skull base meningiomas. The purpose of this study was to evaluate the efficacy of an interdisciplinary treatment approach for symptomatic CSM which incorporated conservative function preserving microsurgery and routine adjuvant fractionated stereotactic radiotherapy (FSRT).

METHODS

A homogenous group of patients with symptomatic primary CSM with extracavernous extension was treated between 2005 and 2012. All patients were available for a minimum follow-up of 5 years. Clinical follow-up included detailed examination of oculomotor deficits, visual status, and endocrinologic function. Radiologic follow-up was conducted by tumor volumetry.

RESULTS

Overall, 23 patients were included in this study (78.3% women; median age 58 years). Diplopia was the most common presenting symptom, followed by headache and visual disturbances. Surgical morbidity was low (3/23; 13%). FSRT was applied after a median of 2 months after surgery. At a median clinical follow-up of 113 months, 70.45% of the presenting symptoms had improved, 25% remained unchanged, and in 2 cases (4.54%), worsening occurred. Overall tumor regression was evident in 19/21 World Health Organization 1 and in 1/2 of World Health Organization 2 CSM, respectively, at a median radiological follow-up of 103 months.

CONCLUSION

Our findings demonstrate the efficacy of an interdisciplinary treatment approach for symptomatic primary CSM with extracavernous extension with decompression of neurovascular elements followed by FSRT. Precise preoperative planning and intraoperative decision making in combination with routine postoperative radiotherapy can achieve excellent tumor control, improve neurologic function, and minimize long-term morbidity.

Long-term Experience of LINAC Single-Dose Radiosurgery for Skull Base Meningiomas: A Retrospective Single-Center Study of 241 Cases

BACKGROUND AND OBJECTIVES

Stereotactic radiosurgery (SRS) is increasingly applied to treat meningiomas, attributable to their increased incidence in older individuals at greater surgical risk. To evaluate the effectiveness of treatment with linear accelerator (LINAC)-based stereotactic radiosurgery in skull base meningiomas as either primary treatment or postresection adjuvant therapy.

METHODS

This study included 241 patients diagnosed with skull base meningiomas treated by single-dose SRS, with a median age of 59 years. SRS was primary treatment in 68.1% (n = 164) and adjuvant treatment in 31.9% (n = 77), using LINAC (Varian 600, 6 MeV). The median tumor volume was 3.2 cm 3 , and the median coverage dose was 14 Gy. Bivariate and multivariate analyses were performed to determine predictive factors for tumor progression, clinical deterioration, and complications. Kaplan-Meier analysis was used for survival analysis.

RESULTS

After the median follow-up of 102 months, the tumor control rate was 91.2% (n = 220). Progression-free survival rates were 97.07%, 90.1%, and 85.7% at 5, 10, and 14 years, respectively. Clinical improvement was observed in 56 patients (23.2%). In multivariate analysis, previous surgery (hazard ratio 3.8 [95%CI 1.136-12.71], P = .030) and selectivity (hazard ratio .21 [95%CI 0.066-0.677], P = .009) were associated with tumor progression and increased maximum dose (odds ratio [OR] 4.19 [95% CI 1.287-13.653], P = .017) with clinical deterioration. The permanent adverse radiation effect rate was 6.2% (n = 15) and associated with maximum brainstem dose >12.5 Gy (OR 3.36 [95% CI .866-13.03], P = .08) and cerebellopontine angle localization (OR 3.93 [95% CI 1.29-11.98], P = .016).

CONCLUSION

Treatment of skull base meningiomas with single-dose SRS using LINAC is effective over the long term. Superior tumor control is obtained in patients without previous surgery. Adverse effects are related to localization in the cerebellopontine angle, and maximum brainstem radiation dose was >12.5 Gy.

Long-Term Outcomes of Stereotactic Radiosurgery for Postoperative World Health Organization Grade I Skull Base Meningioma: Utility of Ki-67 Labeling Index as a Prognostic Indicator

BACKGROUND

Gross total resection, without causing neurological deficits, is challenging in skull base meningioma (SBM). Therefore, stereotactic radiosurgery (SRS) is an important approach for SBMs; however, it is difficult to predict the long-term prognosis.

OBJECTIVE

To identify the predictive factors for tumor progression after SRS for World Health Organization (WHO) grade I SBMs, focusing on the Ki-67 labeling index (LI).

METHODS

In this single-center retrospective study, factors affecting progression-free survival rates (PFSs) and neurological outcomes in patients undergoing SRS for postoperative SBMs were evaluated. Based on the Ki-67 LI, patients were classified into 3 groups: low (<4%), intermediate (4%-6%), and high LI (>6%).

RESULTS

In the 112 patients enrolled, the cumulative 5- and 10-year PFSs were 93% and 83%, respectively. The PFSs were significantly higher in the low LI group (95% at 10 years) compared with the other groups (intermediate LI, 60% at 10 years, P = .007; high LI, 20% at 10 years, P = .001). Multivariable Cox proportional hazard analysis demonstrated that the Ki-67 LI was significantly associated with the PFSs (low vs intermediate LI; hazard ratio, 6.00; 95% CI, 1.41-25.54; P = .015; low vs high LI; hazard ratio, 31.90; 95% CI, 5.59-181.77; P = .001).

CONCLUSION

Ki-67 LI may be a useful predictor of long-term prognosis in SRS for postoperative WHO grade I SBM. SRS provides excellent long- and mid-term PFSs in SBMs with Ki-67 LIs <4% or 4% to 6%, with a low risk of radiation-induced adverse events.

Surgical Treatment of Spheno-Orbital Meningiomas: A Systematic Review and Meta-Analysis of Surgical Techniques and Outcomes

BACKGROUND

Spheno-orbital meningiomas (SOMs) are rare tumors arising from the meninges surrounding the sphenoid bone and orbital structures. Surgical resection is the primary treatment approach for SOMs. Several surgical approaches have been described during the decades, including microsurgical transcranial (MTAs), endoscopic endonasal (EEAs), endoscopic transorbital (ETOAs), and combined approaches, and the choice of surgical approach remains a topic of debate.

PURPOSE

This systematic review and meta-analysis aim to compare the clinical and surgical outcomes of different surgical approaches used for the treatment of SOMs, discussing surgical techniques, outcomes, and factors influencing surgical decision making.

METHODS

A comprehensive literature review of the databases PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted for articles published on the role of surgery for the treatment of SOMs until 2023. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analysis was performed to estimate pooled event rates and assess heterogeneity. Fixed- and random-effects were used to assess 95% confidential intervals (CIs) of presenting symptoms, outcomes, and complications.

RESULTS

A total of 59 studies comprising 1903 patients were included in the systematic review and meta-analysis. Gross total resection (GTR) rates ranged from 23.5% for ETOAs to 59.8% for MTAs. Overall recurrence rate after surgery was 20.7%. Progression-free survival (PFS) rates at 5 and 10 years were 75.5% and 49.1%, respectively. Visual acuity and proptosis improvement rates were 57.5% and 79.3%, respectively. Postoperative cranial nerve (CN) focal deficits were observed in 20.6% of cases. The overall cerebro-spinal fluid (CSF) leak rate was 3.9%, and other complications occurred in 13.9% of cases. MTAs showed the highest GTR rates (59.8%, 95%CI = 49.5-70.2%; p = 0.001) but were associated with increased CN deficits (21.0%, 95%CI = 14.5-27.6%). ETOAs had the lowest GTR rates (23.5%, 95%CI = 0.0-52.5%; p = 0.001), while combined ETOA and EEA had the highest CSF leak rates (20.3%, 95%CI = 0.0-46.7%; p = 0.551). ETOAs were associated with better proptosis improvement (79.4%, 95%CI = 57.3-100%; p = 0.002), while anatomical class I lesions were associated with better visual acuity (71.5%, 95%CI = 63.7-79.4; p = 0.003) and proptosis (60.1%, 95%CI = 38.0-82.2; p = 0.001) recovery. No significant differences were found in PFS rates between surgical approaches.

CONCLUSION

Surgical treatment of SOMs aims to preserve visual function and improve proptosis. Different surgical approaches offer varying rates of GTR, complications, and functional outcomes. A multidisciplinary approach involving a skull base team is crucial for optimizing patient outcomes.

Outcomes and predictors of response to fractionated radiotherapy as primary treatment for intracranial meningiomas

Background

Surgery is the primary treatment for most meningiomas. However, primary fractionated radiotherapy (fRT) remains an option for patients with larger meningiomas in challenging anatomic locations or patients at prohibitively high surgical risk. Outcome prediction for these patients is uncertain and cannot be guided by histopathology without available tumor tissue from surgery. Therefore, we aimed to assess the clinical factors that contribute to treatment failure in a large cohort of meningiomas consecutively treated with fRT as primary therapy, with the goal of identifying predictors of response.

Methods

Patients treated with primary fRT for intracranial meningiomas from 1998 to 2017 were reviewed. Those who received primary surgical resection, radiosurgery, previous fRT, or had <6 months of clinical follow-up were excluded. We applied logistic regression and Cox regression modeling to ascertain key predictors of treatment failure, progression-free survival (PFS), and adverse events (AE) following fRT.

Results

Our cohort included 137 meningiomas, 21 of which progressed after fRT (median PFS 3.45 years). Progressive meningiomas had a larger median gross tumor volume (GTV) compared to those that remained stable (19.1 cm³ vs 9.6 cm³, p = 2.86 × 10^-2). GTV > 11.27 cm³ was independently predictive of progression and larger GTV was associated with higher risk of significant (grades 3/4) AE following fRT. Cavernous sinus and optic nerve sheath meningiomas had overall excellent outcomes post-fRT.

Conclusions

We present a large cohort of meningiomas treated with primary fRT and find GTV and anatomic location to be key predictors of outcome, adding to the complex treatment considerations for this heterogeneous disease.

Re-Irradiation by Stereotactic Radiotherapy of Brain Metastases in the Case of Local Recurrence

PURPOSE

To evaluate the efficacy and safety of a second course of stereotactic radiotherapy (SRT2) treatment for a local recurrence of brain metastases previously treated with SRT (SRT1), using the Hypofractionated Treatment Effects in the Clinic (HyTEC) reporting standards and the European Society for Radiotherapy and Oncology guidelines.

METHODS

From December 2014 to May 2021, 32 patients with 34 brain metastases received salvage SRT2 after failed SRT1. A total dose of 21 to 27 Gy in 3 fractions or 30 Gy in 5 fractions was prescribed to the periphery of the PTV (99% of the prescribed dose covering 99% of the PTV). After SRT2, multiparametric MRI, sometimes combined with 18F-DOPA PET-CT, was performed every 3 months to determine local control (LC) and radionecrosis (RN).

RESULTS

After a median follow-up of 12 months (range: 1-37 months), the crude LC and RN rates were 68% and 12%, respectively, and the median overall survival was 25 months. In a multivariate analysis, the performance of surgery was predictive of a significantly better LC (p = 0.002) and survival benefit (p = 0.04). The volume of a normal brain receiving 5 Gy during SRT2 (p = 0.04), a dose delivered to the PTV in SRT1 (p = 0.003), and concomitant systemic therapy (p = 0.04) were associated with an increased risk of RN.

CONCLUSION

SRT2 is an effective approach for the local recurrence of BM after initial SRT treatment and is a potential salvage therapy option for well-selected people with a good performance status. Surgery was associated with a higher LC.

The multiomic landscape of meningiomas: a review and update

PURPOSE

Meningiomas are the most common primary brain tumor in adults. Traditionally they have been understudied compared to other central nervous system (CNS) tumors. However over the last decade, there has been renewed interest in uncovering the molecular topography of these tumors, with landmark studies identifying key driver alterations contributing to meningioma development and progression. Recent work from several independent research groups have integrated different genomic and epigenomic platforms to develop a molecular-based classification scheme for meningiomas that could supersede histopathological grading in terms of diagnostic accuracy, biological relevance, and outcome prediction, keeping pace with contemporary grading schemes for other CNS tumors including gliomas and medulloblastomas.

METHODS

Here we summarize the studies that have uncovered key alterations in meningiomas which builds towards the discovery of consensus molecular groups in meningiomas by integrating these findings. These groups supersede WHO grade and other clinical factors in being able to accurately predict tumor biology and clinical outcomes following surgery.

RESULTS

Despite differences in the nomenclature of recently uncovered molecular groups across different studies, the biological similarities between these groups enables us to likely reconciliate these groups into four consensus molecular groups: two benign groups largely dichotomized by NF2-status, and two clinically aggressive groups defined by their hypermetabolic transcriptome, and by their preponderance of proliferative, cell-cycling pathways respectively.

CONCLUSION

Future work, including by our group and others are underway to validate these molecular groups and harmonize the nomenclature for routine clinical use.

Surgical complications and recurrence factors for asymptomatic meningiomas: a single-center retrospective study

PURPOSE

Observation is the first management option in asymptomatic meningiomas, but when an enlargement or mass effect is observed, surgery is indicated. This study is aimed at exploring risk factors for complications and recurrence after surgery for asymptomatic meningioma. We also examined the impact of preoperative tumor embolization, which is considered controversial.

METHODS

We retrospectively reviewed 109 patients with primary asymptomatic meningiomas surgically treated at our institute between April 2007 and March 2021. Patients who only had headaches as a nonspecific complaint were included in the asymptomatic group. Complications, time to recurrence, and Glasgow Outcome Scale (GOS) score were the endpoints of the study. Risk factors for complications and recurrence were explored. Moreover, the effect of the resection on nonspecific headaches was also explored.

RESULTS

The permanent postoperative complication rate related to the surgical procedure was 1.8%. Of the total, 107 patients (98.2%) with asymptomatic meningiomas who were surgically treated achieved a GOS score of 5 1 year after the operation. Preoperative headache was present in 31 patients and improved postoperatively in 21 patients. Multivariate analysis using the Cox proportional hazard model showed that preoperative tumor embolization with > 80% resolution of tumor staining (p < 0.001) was negatively related to recurrence, whereas age (p = 0.046) and Simpson grade IV resection (p = 0.041) were positively related to recurrence.

CONCLUSION

Although surgery for asymptomatic meningiomas can, in many cases, be safe, it is not free of complications Thus, surgical intervention for asymptomatic meningiomas should be considered cautiously. However, more than half the patients with headaches showed improvement. Simpson grade IV resection cases should be assessed for recurrence, and preoperative tumor embolization might be effective in controlling recurrence.

Does Endoscopic Transnasal Optic Nerve Decompression Followed by Radiosurgery Improve Outcomes in the Treatment of Parasellar Meningiomas?

Introduction: The clinical management of parasellar meningiomas (PM) is challenging due to their intimate association with critical neurovascular structures. Consensus regarding the recommended treatment protocol is lacking. This study will evaluate patients’ visual outcomes following endoscopic transnasal optic nerve decompression (ETOND) and will investigate the possibility of reducing the rate of complications associated with stereotactic radiosurgery (SRS). Methods: Retrospective analysis was conducted on all patients who underwent ETOND for PM between 2013 and 2020. The study comprised 12 patients (7 women and 5 men aged 36–75 years; mean, 55.2 years; median, 57.6 years) in which 14 optic nerve decompression procedures were carried out. Patients were followed up for 6 to 86 months (mean, 29.3 months; median, 25 months). There were five cases of spheno-orbital meningioma, four cases of cavernous sinus meningioma, and one case each of petro-clival meningioma, optic nerve sheath meningioma, and planum sphenoidale/tuberculum sellae meningioma. Visual outcome was evaluated and any postoperative complications noted. Results: Improvements in visual acuity were noted in 10 of 14 eyes (71.4%) 3 to 6 months postoperation. Visual acuity remained stable in the remaining four eyes. No deterioration of visual acuity was noted during the follow-up period. In total, 9 of the 12 patients underwent SRS. No tumor growth was determined, while reduction in tumor volume was noted in five patients following SRS. No complications associated with SRS or the surgical procedure were noted. Conclusions: ETOND appears to be a promising technique for increasing rates of improved visual function, while reducing the risk of post SRS-related complications. In combination with subsequent SRS, it is an ideal treatment modality in the management of parasellar meningiomas. Confirmation of our findings would require a larger, prospective multicenter study.

Clinical outcomes of benign brain tumors treated with single fraction LINAC-based stereotactic radiosurgery: Experience of a single institute

Objectives

Accelerator-based stereotactic radiosurgery (SRS) is a noninvasive and effective treatment modality widely used for benign brain tumors. This study aims to report 20-year treatment outcomes in our institute.

Materials and Methods

From May 2001 to December 2020, 127 patients treated with LINAC-based single-fraction SRS for their benign brain lesions were included. A neurosurgeon and two radiation oncologists retrospectively reviewed all data. Computed tomography (CT) simulation was performed after head-frame fixation under local anesthesia. All planning CT images were co-registered and fused with gadolinium-enhanced magnetic resonance imaging taken within 3 months for lesions targeting and critical organs delineation. The marginal dose was prescribed at 60%-90% isodose lines, respectively, to cover ≥95% planning target volume. Outcome evaluations included clinical tumor control rate (TCR), defined as the need for salvage therapy, and radiological response, defined as no enlargement of >2 cm in the maximal diameter. Overall survival (OS) and adverse reaction (defined according to CTCAE 5.0) were also analyzed.

Results

The present study included 76 female and 51 male patients for analysis. The median age was 59 years (range, 20-88 years). Their diagnoses were vestibular schwannoma (VS, n = 54), nonvestibular cranial nerve schwannoma (n = 6), meningioma (n = 50), and pituitary adenoma (n = 17). Totally 136 lesions were treated in a single fraction, predominantly skull base tumors, accounting for 69.1%. Median and mean follow-up duration was 49 and 61 months (range, 1-214 months), Overall TCR was 92.9%. The 5-year disease-specific TCR for VS, nonvestibular schwannoma, meningioma, and pituitary adenoma were 97.4%, 91.7%, 93.8%, and 83.3%. Salvage therapy was indicated for eight patients at 4-110 months after SRS. Among symptomatic patients, post-SRS symptom(s) was improved, stable, and worse in 68.2%, 24.3%, and 3.6%, respectively. Radiological response rate for 111 evaluable patients was 94.6% (shrinkage, 28.8%; stable, 65.8%). OS was 96.1% without treatment-related mortality. One patient with post-SRS cranial nerve injury (0.8%, involving the trigeminal nerve, grade 2 toxicities). No grade 3-4 acute or late toxicity was found.

Conclusion

Our results suggested that LINAC-based SRS effectively controls tumor growth and tumor-related neurological symptoms for patients with benign brain tumors. SRS is less aggressive, associated with low neurological morbidity and no mortality. Continuous follow-up is indicated to conclude longer outcomes.

Midline Skull Base Meningiomas: Transcranial and Endonasal Perspectives

Simple Summary

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. Over time, several corridors have been proposed, each one carrying its own pros and cons. During the last decades, the endoscopic endonasal route has been asserted among the classic routes for a growing number of midline and paramedian lesions. Therefore, the aim of our paper is to present a comprehensive review of the indications and techniques for the management of skull base meningiomas, emphasizing the ambivalent and complementary role of the low and high routes.

Abstract

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. The state of the art of skull base meningiomas accounts for both transcranial, or high, and endonasal, or low, routes. A comprehensive review of the pertinent literature was performed to address the surgical strategies and outcomes of skull base meningioma patients treated through a transcranial approach, an endoscopic endonasal approach (EEA), or both. Three databases (PubMed, Ovid Medline, and Ovid Embase) have been searched. The review of the literature provided 328 papers reporting the surgical, oncological, and clinical results of different approaches for the treatment of skull base meningiomas. The most suitable surgical corridors for olfactory groove, tuberculum sellae, clival and petroclival and cavernous sinus meningiomas have been analyzed. The EEA was proven to be associated with a lower extent of resection rates and better clinical outcomes compared with transcranial corridors, offering the possibility of achieving the so-called maximal safe resection.

Gamma Knife radiosurgery for tuberculum sellae meningiomas: a series of 78 consecutive patients

Outcomes of Gamma Knife radiosurgery (GKRS) for tuberculum sellae meningiomas (TSMs) have not been reported explicitly within any meningioma series. We present the first and largest TSM series with clinical, radiosurgical, and outcome features for 78 consecutive patients managed with GKRS. Patients who underwent GKRS for TSMs between 2005 and 2021 and had a minimum of 6 months of follow-up were included. Medical records, imaging studies, and follow-up examinations were evaluated retrospectively. A total of 78 patients with a median age of 50.5 years were included. SRS was conducted as an upfront treatment for 38 patients (48.7%). The median target volume was 1.7 cm³ (range, 0.1-14.6). During a median follow-up of 78.5 months, the cumulative PFS rates of the whole cohort at 1, 5, and 10 years by Kaplan-Meier analysis were 100%, 97.9%, and 94.5%, respectively. Of 47 patients with impaired vision, improvement and/or preservation of visual acuity, and visual field were achieved in 55.3% and 42.6%, respectively. No new-onset hormonal deficits were observed. Based on our data, SRS represents an effective and safe modality for unresected or recurrent/residual TSMs. SRS should be offered to patients who are not willing or not ideal candidates for surgery.

Meningioma Treated With Hypofractionated Stereotactic Radiotherapy Using CyberKnife®: First in the United Arab Emirates

A 26-year-old premenopausal lady was referred to the Department of Oncology with headaches and easy fatiguability. She had presented with the same complaints a few years ago. At that time, imaging revealed a right falcine space-occupying lesion (SOL), for which she underwent an unsuccessful attempt of excision. Imaging studies confirmed that the SOL was progressive and arose from the meninges. Previous excision failure was due to a network of blood vessels around the tumor and critical structures such as the thalamus and the brainstem, which made any approach challenging.

The patient did not want further surgery and requested a non-surgical intervention. Considering the above, the case was discussed at the Multi-Disciplinary Tumor Board, and treatment with hypofractionated stereotactic radiotherapy using CyberKnife® was agreed upon. The patient received a total of 21 Gy in three fractions over six days and completed the treatment without any adverse reactions.

This is the first case treated with hypofractionated stereotactic radiotherapy using the CyberKnife® in the United Arab Emirates, which is an effective and safe modality to treat similar challenging cases.

Meningiomas

Meningiomas arise in various locations. Convexity tumors are relatively simple to remove. Skull base tumors and tumors adjacent to the major cerebral veins and venous sinuses can be very difficult to extirpate. Attempts at radical resection can lead to serious morbidity. The combination of bulk reduction using microsurgery followed by GKNS gives greatly improved survival and very low morbidity. With smaller tumors, GKNS may be used as the primary treatment. Increasing numbers of asymptomatic meningiomas are demonstrated either as an unexpected finding or as a residual or recurrent tumor after surgery. In all of these situations, GKNS gives a better result than observation or reoperation.

Management of cavernous sinus meningiomas: Consensus statement on behalf of the EANS skull base section

Introduction

The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs.

Research question

To determine the best overall management of CSMs, depending on their clinical presentation, size, and evolution as well as patient characteristics.

Material and methods

Using the PRISMA 2020 guidelines, we included literature from January 2000 to December 2020. A total of 400 abstracts and 77 titles were kept for full-paper screening.

Results

The task force formulated 8 recommendations (Level C evidence). CSMs should be managed by a highly specialized multidisciplinary team. The initial evaluation of patients includes clinical, ophthalmological, endocrinological and radiological assessment. Treatment of CSM should involve experienced skull-base neurosurgeons or neuro-radiosurgeons, radiation oncologists, radiologists, ophthalmologists, and endocrinologists.

Discussion and conclusion

Radiosurgery is preferred as first-line treatment in small, enclosed, pauci-symptomatic lesions/in elderly patients, while large CSMs not amenable to resection or WHO grade II-III are candidates for radiotherapy. Microsurgery is an option in aggressive/rapidly progressing lesions in young patients presenting with oculomotor/visual/endocrinological impairment. Whenever surgery is offered, open cranial approaches are the current standard. There is limited experience reported about endoscopic endonasal approach for CSMs and the main indication is decompression of the cavernous sinus to improve symptoms. Whenever surgery is indicated, the current trend is to offer decompression followed by radiosurgery.

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A thorough evaluation of cavernous sinus meningiomas by a multidisciplinary team is mandatory.

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Microsurgery should be considered for aggressive lesions in young patients.

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Extended endoscopic approaches can be effective when combined with radiotherapy.

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Stereotaxic radiotherapy and stereotaxic radiosurgery offer excellent tumour control in small/asymptomatic lesions .

EANO guideline on the diagnosis and management of meningiomas

Meningiomas are the most common intracranial tumors. Yet, only few controlled clinical trials have been conducted to guide clinical decision making, resulting in variations of management approaches across countries and centers. However, recent advances in molecular genetics and clinical trial results help to refine the diagnostic and therapeutic approach to meningioma. Accordingly, the European Association of Neuro-Oncology (EANO) updated its recommendations for the diagnosis and treatment of meningiomas. A provisional diagnosis of meningioma is typically made by neuroimaging, mostly magnetic resonance imaging. Such provisional diagnoses may be made incidentally. Accordingly, a significant proportion of meningiomas, notably in patients that are asymptomatic or elderly or both, may be managed by a watch-and-scan strategy. A surgical intervention with tissue, commonly with the goal of gross total resection, is required for the definitive diagnosis according to the WHO classification. A role for molecular profiling including gene panel sequencing and genomic methylation profiling is emerging. A gross total surgical resection including the involved dura is often curative. Inoperable or recurrent tumors requiring treatment can be treated with radiosurgery, if the size or the vicinity of critical structures allows that, or with fractionated radiotherapy (RT). Treatment concepts combining surgery and radiosurgery or fractionated RT are increasingly used, although there remain controversies regard timing, type, and dosing of the various RT approaches. Radionuclide therapy targeting somatostatin receptors is an experimental approach, as are all approaches of systemic pharmacotherapy. The best albeit modest results with pharmacotherapy have been obtained with bevacizumab or multikinase inhibitors targeting vascular endothelial growth factor receptor, but no standard of care systemic treatment has been yet defined.

Efficacy and Safety of a Second Course of Stereotactic Radiation Therapy for Locally Recurrent Brain Metastases: A Systematic Review

Recent advances in cancer treatments have increased overall survival and consequently, local failures (LFs) after stereotactic radiotherapy/radiosurgery (SRS/SRT) have become more frequent. LF following SRS or SRT may be treated with a second course of SRS (SRS2) or SRT (SRT2). However, there is no consensus on whenever to consider reirradiation. A literature search was conducted according to PRISMA guidelines. Analysis included 13 studies: 329 patients (388 metastases) with a SRS2 and 135 patients (161 metastases) with a SRT2. The 1-year local control rate ranged from 46.5% to 88.3%. Factors leading to poorer LC were histology (melanoma) and lack of prior whole-brain radiation therapy, large tumor size and lower dose at SRS2/SRT2, poorer response at first SRS/SRT, poorer performance status, and no controlled extracranial disease. The rate of radionecrosis (RN) ranged from 2% to 36%. Patients who had a large tumor volume, higher dose and higher value of prescription isodose line at SRS2/SRT2, and large overlap between brain volume irradiated at SRS1/SRT1 and SRS2/SRT2 at doses of 18 and 12 Gy had a higher risk of developing RN. Prospective studies involving a larger number of patients are still needed to determine the best management of patients with local recurrence of brain metastases.

Radiation-induced cavernous malformation after stereotactic radiosurgery for cavernous sinus meningioma: a case report

Background

Radiation-induced cavernous malformation (RICM) is a rare sequela of stereotactic radiosurgery (SRS) treatment of intracranial tumors. To date, no study reported on RICM after SRS for meningiomas originating from the skull base. The relationship between locus of initial meningioma and RICM has not been studied.

Case presentation

A 57-year-old woman presented with persistent headaches and blepharoptosis at initial episode. MRI disclosed a right parasellar lesion, diagnosed as a cavernous sinus meningioma (CSM). After receiving a single-fractionated SRS, headache relieved, but blepharoptosis did not significantly improve. Three years and three months later, she returned with headaches and dizziness. MRI showed an enlarged CSM. Moreover, a new mass-like lesion, suspected hemangioma, appeared in the nearby right temporal lobe. After surgical removal of the new lesion and the CSM, the patient’s neurological symptoms significantly improved. Pathology confirmed CSM and temporal RICM.

Conclusions

We report the first rare case of RICM occurring after SRS for CSM. The RICM may be in the same region as the initial tumor. Surgical intervention was preferred for symptomatic RICM and initial meningioma. We recommend long-term regular followup MRIs for patients with meningioma after SRS treatment.

Trigeminal Neuralgia Secondary to Meningiomas and Vestibular Schwannoma Is Improved after Stereotactic Radiosurgery: A Systematic Review and Meta-Analysis

INTRODUCTION

Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting the trigeminal nerve pathways. The most frequent are meningiomas and vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has emerged as a valuable treatment, with heterogeneity of clinical results. We sought to review the medical literature on TN treated with SRS for meningiomas and VS and investigate the rates of improvement of TN symptoms.

METHODS

We reviewed articles published between January 1990 and December 2019 in PubMed. Pain relief after SRS, the maintenance of pain relief, and TN recurrence and complications were evaluated with separate meta-analyses, taking into account the data on individual patients.

RESULTS

Pain relief after SRS was reported as Barrow Neurological Institute (BNI) pain intensity scores of BNI I in 50.5% (range 36-65.1%) of patients and BNI I-IIIb in 83.8% (range 77.8-89.8%). There was no significant difference in series discussing outcomes for tumor targeting versus tumor and nerve targeting. Recurrences were described in 34.7% (range 21.7-47.6; tumor targeting). Maintenance of BNI I was reported in 36.4% (range 20.1-52.7) and BNI I-IIIb in 41.2% (range 29.8-52.7; tumor targeting series). When both the nerve and the tumor were targeted, only 1 series reported 86.7% with BNI I-IIIb at last follow-up. Complications were encountered in 12.6% (range 6.3-18.8; tumor targeting series) of patients; however, they were much higher, as high as 26.7%, in the only study reporting them after targeting both the nerve and the tumor. The most common complication was facial numbness.

CONCLUSION

SRS for TNB secondary to benign tumors, such as meningiomas and VS, is associated with favorable clinical course, but less favorable than in idiopathic TN. There was, however, heterogeneity among reports and targeting approaches. Although targeting both the nerve and the tumor seemed to achieve better long-term results, the rate of complications was much higher and the number of patients treated was limited. Future clinical studies should focus on the standard reporting of clinical outcomes and randomization of targeting methods.

Ten-year follow-up after Gamma Knife radiosurgery of meningioma and review of the literature

Objectives

With regard to the generally slow growth of meningioma, it is essential to analyse clinical treatment results in a long-term perspective. The purpose of the present analysis is to provide clinical data after Gamma Knife radiosurgery of meningioma in a 10-year perspective together with a review of the current literature.

Methods

The current study is a retrospective analysis of 86 consecutive Swedish patients with meningiomas treated using Gamma Knife radiosurgery at the Karolinska Hospital Stockholm between March 1991 and May 2001. A total of 130 tumours were treated in 115 treatment sessions. The median radiological follow-up was 10 years (1.8–16.5 years), and the median clinical follow-up was 9.4 years (2.1–17.4 years).

Results

After a median follow-up period of 10 years, local tumour control was achieved in 87.8% of meningiomas (108/123 tumours). The median latency between initial treatment and local (in-field) recurrence (n = 15) was 5.8 years (1.9–11.5). Recurrences adjacent but outside the initial radiation field occurred in 15.1% of patients (13/86) at a median of 7.5 years (1.3–15.7). New meningiomas were seen in 10.5% after a median of 5.4 years (0.9–10.8). In 72% of patients, no further treatment was required, 17.4% (15/86) underwent a second Gamma Knife treatment, 4.7% (4/86) required later open surgery and 5.8% (5/86) required both secondary treatments. Eighty-six percent of patients were neurologically unchanged or improved. A significantly lower rate of local (in-field) recurrences was seen in meningiomas treated with a prescription dose of > 13.4 Gy (7.1% vs. 24%, p = 0.02).

Conclusions

The current retrospective analysis provides a 10-year follow-up and comprises one of the longest available follow-up studies of radiosurgically treated meningiomas. The current series documents a persistent high local tumour control after Gamma Knife treatment, while providing an estimation of a necessary minimum dose for long-term tumour control in meningiomas. The study confirms the validity of previous short-term data in a long-term perspective.

Patterns of recurrence in patients receiving conformal radiation for intracranial meningioma: a single-institution experience

Aim:

To evaluate the patterns of recurrence following postoperative conformal radiotherapy (RT) for intracranial meningioma.

Materials and methods:

Eighty-six patients who received conformal RT for intracranial meningiomas from 2014 to 2017 were retrospectively analysed. For documented recurrences, recurrence imaging was deformably co-registered to planning CT scan. In-field recurrence was defined as recurrence within the 90% isodose line, and out-of-field recurrences were those that occurred outside the 90% isodose line. We present the demographic details, surgical and RT details, outcomes and patterns of recurrence.

Results:

The median age was 46 years (range 17–72); 82·6% underwent surgery [46·5% had subtotal resection (STR), 43·7% gross tumour resection (GTR), 5·6% biopsy] and 17·4% had no surgery. Among these, 53·5% were WHO grade 2; 27·9% grade 1; and 1·2% grade 3 meningioma. Fifty per cent received stereotactic RT (SRT), 46·5% 3D conformal RT (3DCRT) and 3·5% intensity-modulated RT (IMRT). The mean clinical target volume (CTV) and planning target volume (PTV) margins were 4·5 mm (range 0–15) and 3·9 mm (range 1–5), respectively. The doses ranged from 54 to 59·4 Gy. The median follow-up after RT was 1·7 years (range 0·2–4·7). 17·4% were lost to follow-up, 5·4% had recurrence, and the median time to recurrence after completion of RT was 2 years (range 0·7–2·9). The 3-year recurrence-free rate was 81·5%. Three patients had in-field and two had in-field and out-of-field recurrence. Among the cases with recurrence, three received SRT, one 3DCRT and one IMRT. Four were grade 2 and one was grade 3 tumour, and the CTV margin ranged from 0 to 5 mm, and the PTV margin ranged from 3 to 5 mm.

Conclusion:

Local recurrence was seen in grade 2 and 3 meningiomas. SRT probably had more recurrence as they had lesser CTV margin. Increased CTV margin, escalated dose up to 59·4 Gy and 3DCRT/IMRT may be helpful in preventing local recurrences in grade 2 and grade 3 meningiomas.

Comparison of clinical outcomes in patients who underwent Gamma Knife radiosurgery for parasellar meningiomas with or without prior surgery

Background

Parasellar meningioma is a common benign tumour in brain. Both surgery and radiosurgery are important treatment modalities for this tumour. The study was designed to investigate whether prior surgery would affect treatment outcomes of patients with parasellar meningiomas after management with Gamma Knife radiosurgery.

Methods

A total of 93 patients who received Gamma Knife surgery were included in this retrospective study. There were 30 males and 63 females, with a median age of 48.6 years (range, 15.2–78.7 years). Prior surgery was performed in 45 patients. The median tumor volume was 5.02 cm³ (range 1.07–35.46 cm³) and median marginal dose was 12 Gy (range 10–15 Gy). The mean imaging follow-up and clinical follow-up periods were 40.7 and 52.7 months, respectively.

Results

In the group without prior surgery, 31 patients had improvement of preexisting symptoms; and in the group with prior surgery, 20 patients were noted to improve. The difference in symptom improvement between the two groups reached statistical significance (P = 0.009). Patients with prior surgery were more likely to have stable symptoms after Gamma Knife surgery (P = 0.012). Tumor recurrence was reported in 8 patients out of 45 patients with prior surgery, and 3 patients out of 48 patents without prior surgery (P = 0.085). After Gamma Knife surgery, 5 and 4 patients in two groups developed new neurological symptoms, respectively (P = 0.651). Cox regression analysis identified follow-up period as prognostic factor of progression-free survival. Ordinal logistic regression analysis identified surgery prior to Gamma Knife surgery as an unfavorable factor of symptom change.

Conclusion

Gamma Knife radiosurgery provided long-term effective tumor control and better symptom recovery compared with those with prior surgery. Patients with surgery before Gamma Knife radiosurgery were more likely to have stable symptoms. Further analyses indicated that long follow-up is essential to determine the efficacy of radiosurgery for parasellar meningiomas. Further study needs to include more patients with longer follow-up to draw a more solid conclusion.

Radiotherapy of Parasellar Tumours

Parasellar tumours represent a wide group of intracranial lesions, both benign and malignant. They may arise from several structures located within the parasellar area or they may infiltrate or metastasize this region. The treatment of the tumours located in these areas is challenging because of their complex anatomical location and their heterogenous histology. It often requires a multimodal approach, including surgery, radiation therapy (RT), and medical therapy. Due to the proximity of critical structures and the risks of side effects related to the procedure, a successful surgical resection is often not achievable. Thus, RT plays a crucial role in the treatment of several parasellar tumours. Conventional fractionated RT and modern radiation techniques, like stereotactic radiosurgery and proton beam RT, have become a standard management option, in particular for cases with residual or recurrent tumours after surgery and for those cases where surgery is contraindicated. This review examines the role of RT in parasellar tumours analysing several techniques, outcomes and side effects.

Parasellar Meningiomas

Parasellar spaces remain particularly singular, comprising the most important neurovascular structures such as the internal carotid artery and optic, oculomotor, and trigeminal nerves. Meningiomas are one of the most frequent tumors arising from parasellar spaces. In this location, meningiomas remain mostly benign tumors with WHO grade I and a meningothelial subtype. Progestin intake should be investigated and leads mostly to conservative strategies. In the case of benign nonsymptomatic tumors, observation should be proposed. Tumor growth will lead to the proposition of surgery or radiosurgery. In the case of an uncertain diagnosis and an aggressive pattern, a precise diagnosis is required. For cavernous sinus and Meckel's cave lesions, complete removal is rarely considered, leading to the proposition of an endoscopic endonasal or transcranial biopsy. Optic nerve decompression could also be proposed via these approaches. A case-by-case discussion about the best approach is recommended. A transcranial approach remains necessary for tumor removal in most cases. Vascular injury could lead to severe complications. Cerebrospinal fluid leakage, meningitis, venous sacrifice, visual impairment, and cranial nerve palsies are more frequent complications. Pituitary dysfunctions are rare in preoperative assessment and in postoperative follow-up but should be assessed in the case of meningiomas located close to the pituitary axis. Long-term follow-up is required given the frequent incomplete tumor removal and the risk of delayed recurrence. Radiosurgery is relevant for small and well-limited meningiomas or intra-cavernous sinus postoperative residue, whereas radiation therapy and proton beam therapy are indicated for large, extended, nonoperable meningiomas. The place of the peptide receptor radionuclide therapyneeds to be defined. Targeted therapy should be considered in rare, recurrent, and aggressive parasellar meningiomas.

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.

Linear Accelerator-Based Radiosurgery of Grade I Intracranial Meningiomas

Objective

To determine the local control rate and complication rate in the treatment of grade I intracranial meningiomas.

Methods

A retrospective study was performed of patients with grade I meningioma who received radiosurgery with a dedicated linear accelerator from January 2002 to August 2012 with a minimum follow-up of 2 years. We performed descriptive statistics, logistic regression, and progression-free survival analysis through a Kaplan-Meier curve.

Results

Seventy-five patients with 78 grade I meningiomas received radiosurgery, 39 underwent surgery plus adjuvant radiosurgery, and 36 only radiosurgery. The follow-up median time was 68 months (range, 35–120 months). The tumor control rate was 93%, the 5-year progression-free survival was 92% (95% confidence interval, 77%–98%). Acute toxicity was 2.6%, and grade 1–2 late toxicity was 26.6%. Postradiosurgery edema was the main late morbidity. Age >55 years was the only significant factor for attaining a response >75%. The background of surgery before radiosurgery was the only significant prognostic factor for showing edema (odds ratio 5.78 [95% confidence interval, 2.14–15.64]).

Conclusions

The local control rate attained in our series is similar to that reported in other series worldwide; the acute toxicity rate was low and late toxicity was moderate.

Treatment of Asymptomatic Meningioma With Gamma Knife Radiosurgery: Long-Term Follow-up With Volumetric Assessment and Clinical Outcome

BACKGROUND

Some patients are diagnosed with asymptomatic meningioma(s) after undergoing a screening CT and MRI for minor ailments or postresection.

OBJECTIVE

To help clinicians in decision making for treatment of asymptomatic meningiomas.

METHODS

A single center retrospective cohort study of 117 patients with 122 tumors treated with Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden). Patients were followed with longitudinal imaging and clinical evaluations. Tumor volumetry and developments of new signs or symptoms after GKRS were the end points in the study.

RESULTS

Median patient age at GKRS was 60 yr (range 21-86 yr) with a median clinical follow-up of 53 mo (range 20-252 mo). The median pre-GKRS tumor volume was 3.6 ± 3.8 cc (±standard deviation). Tumors were treated with a median margin dose of 14 ± 2 Gy. At last follow-up, median tumor volume was 2.5 ± 3.6 cc. Radiological progression-free survival (PFS) rates were 97% and 94.4% at 5 yr and 10 yr, respectively. Clinical PFS rates were 86% and 70% at 5 yr and 10 yr, respectively. Development of neurological complications was seen in 21 (18%) patients, and 11 (52%) of them had undergone surgical resection prior to GKRS.

CONCLUSION

GKRS is a reasonable treatment strategy for asymptomatic meningiomas and compares favorably to natural history studies in terms of tumor control and neurological preservation. It results in relatively low morbidity in previously untreated meningiomas and serves as an appealing alternative treatment modality for recurrent meningiomas in asymptomatic patients.

Stereotactic Radiosurgery of Cavernous Sinus Meningiomas

Objective  Microsurgical resection of cavernous sinus meningiomas (CSM) is associated with a high rate of incomplete resection, recurrence, and the risk for permanent, severe cranial nerve deficits. Stereotactic radiosurgery (SRS) has evolved as alternative treatment for primary and recurrent CSM. Here, we report about the long-term clinical and radiological follow-up (FU) of a unique cohort of patients with CSM treated with LINAC or Cyberknife based SRS. Methods  In this single-center retrospective analysis, we include all patients with CSM who underwent single fraction SRS between 1993 and 2016. Clinical and radiological tumor control were evaluated by the Kaplan-Meier method. Additionally, patient data were analyzed in terms of symptom control and incidence of side effects rated by the common terminology criteria for adverse events (CTCAE; v4.03). Results  116 patients (female/male = 91/25; median age, 54 years; range, 33-82 years) were included. Mean tumor volume was 5.7 ± 3.3 cm ³ (range, 0.6-16.2 cm ³ ), the median marginal dose was 12.6 Gy applied to isodose levels of 75%. Median clinical FU was 55 months (range, 3-226 months). Tumor control was 98% after 2 and 5 years and 90% after 10 years. Twelve patients (10.3%) had permanent or transient radiation related toxicity (CTCAE I-III). An improvement of symptoms was observed in 26.7% of the symptomatic patients ( n  = 20 of 75). Conclusion  SRS for CSM provides excellent long-term tumor and symptom control without considerable permanent side effects. Thus, SRS should be considered when counseling patients suffering from CSM.

Adaptive Hybrid Surgery: Paradigm Shift for Patient-centered Neurosurgery

The surgical management of cerebral and skull base lesions has evolved greatly in the last few decades. Still, a complete resection of lesions abutting critical neurovascular structures carries significant morbidity. Stereotactic radiosurgery (SRS) has emerged as an increasingly accepted treatment option. Minimally invasive, SRS results in excellent tumor control and low complication rates in patients with moderate-size tumors. The management of large cerebral and skull base tumors remains a formidable challenge. In such large tumors, radical surgical extirpation offers a significantly higher risk of neurological deficit, and SRS alone cannot be used because of the elevated incidence of radiation-induced complications known to be associated with large-volume tumors. With increasing treatment volumes, SRS-associated tumor control rates decrease and complication rates increase. Planned subtotal resection (STR) with adjuvant SRS (adaptive hybrid surgery [AHS]) has gained increasing interest in recent years as a multimodal approach. In AHS, a planned STR (aimed at decreasing surgical morbidity) followed by SRS to a preplanned residual tumor aids in harnessing advantages offered by both approaches. Although intuitive and reasonable, this paradigm shift from maximal resection at all cost has not been adopted widely. Combining open microsurgery with SRS requires a good understanding of both surgical and SRS modalities and their respective safety-efficacy features. We present a review and discussion on AHS as a modern, multidisciplinary treatment approach. Available data and views are discussed for vestibular schwannoma (VS) as a sample tumor. Other indications for AHS are mentioned in brief.