Adjuvant postoperative high-dose radiotherapy for atypical and malignant meningioma: A phase-II parallel non-randomized and observation study (EORTC 22042-26042)

Radiotherapy intensification for atypical and malignant meningiomas: A systematic review

Background

The outcomes of nonbenign (WHO Grades 2 and 3 [G2, G3]) meningiomas are suboptimal and radiotherapy (RT) dose intensification strategies have been investigated. The purpose of this review is to report on clinical practice and outcomes with particular attention to RT doses and techniques.

Methods

The PICO criteria (Population, Intervention, Comparison, and Outcomes) were used to frame the research question, directed at outlining the clinical outcomes in patients with G2-3 meningiomas treated with RT. The same search strategy was run in Embase and MEDLINE and, after deduplication, returned 1 807 records. These were manually screened for relevance and 25 were included.

Results

Tumor outcomes and toxicities are not uniformly reported in the selected studies since different endpoints and time points have been used by different authors. Many risk factors for worse outcomes are described, the most common being suboptimal RT. This includes no or delayed RT, low doses, and older techniques. A positive association between RT dose and progression-free survival (PFS) has been highlighted by analyzing the studies in this review (10/25) that report the same endpoint (5y-PFS).

Conclusions

This literature review has shown that standard practice RT leads to suboptimal tumor control rates in G2-3 meningiomas, with a significant proportion of disease recurring after a relatively short follow-up. Randomized controlled trials are needed in this setting to define the optimal RT approach. Given the increasing data to suggest a benefit of higher RT doses for high-risk meningiomas, novel RT technologies with highly conformal dose distributions are preferential to achieve optimal target coverage and organs at risk sparing.

Factors influencing postoperative visual improvement in 208 patients with tuberculum sellae meningiomas

OBJECTIVE

Tuberculum sellae meningiomas (TSMs) usually compress the optic nerve and optic chiasma, thus affecting vision. Surgery is an effective means to remove tumors and improve visual outcomes. On a larger scale, this study attempted to further explore and confirm the factors related to postoperative visual outcomes to guide the treatment of TSMs.

METHODS

Data were obtained from 208 patients with TSMs who underwent surgery at our institution between January 2010 and August 2022. Demographics, ophthalmologic examination results, imaging data, extent of resection, radiotherapy status, and surgical approaches were included in the analysis. Univariate and multivariate logistic regressions were used to assess the factors that could lead to favorable visual outcomes.

RESULTS

The median follow-up duration was 63 months, and gross total resection (GTR) was achieved in 174 (83.7%) patients. According to our multivariate logistic regression analysis, age < 60 years (odds ratio [OR] = 0.310; P = 0.007), duration of preoperative visual symptoms (DPVS) < 10 months (OR = 0.495; P = 0.039), tumor size ≤ 27 mm (OR = 0.337; P = 0.002), GTR (OR = 3.834; P = 0.006), and a tumor vertical-to-horizontal dimensional ratio < 1 (OR = 2.593; P = 0.006) were found to be significant independent predictors of favorable visual outcomes.

CONCLUSION

Age, DPVS, tumor size, GTR, and the tumor vertical-to-horizontal dimensional ratio were found to be powerful predictors of favorable visual outcomes. This study may help guide decisions regarding the treatment of TSMs.

A Prospective Registry Study of 68Ga-DOTATATE PET/CT Incorporation Into Treatment Planning of Intracranial Meningiomas

PURPOSE

The current standard for meningioma treatment planning involves magnetic resonance imaging-based guidance. Somatostatin receptor ligands such as 68Ga-DOTATATE are being explored for meningioma treatment planning due to near-universal expression of somatostatin receptors 1 and 2 in meningioma tissue. We hypothesized that 68Ga-DOTATATE positron emission tomography (PET)-guided treatment management for patients with meningiomas is safe and effective and can identify which patients benefit most from adjuvant radiation therapy.

METHODS AND MATERIALS

A single-institution prospective registry study was created for inclusion of patients with intracranial meningiomas who received a 68Ga-DOTATATE PET/CT to assist with radiation oncologist decision making. Patients who received a PET scan from January 1, 2018, to February 25, 2022, were eligible for inclusion.

RESULTS

Of the 60 patients included, 40%, 47%, and 5% had World Health Organization grades 1, 2, and 3 meningiomas, respectively, and 8% (5 patients) had no grade assigned. According to Radiation Therapy Oncology Group 0539 criteria, 22%, 72%, and 7% were categorized as high, intermediate, and low risk, respectively. After completing their PET scans, 48 patients, 11 patients, and 1 patient proceeded with radiation therapy, observation, and redo craniotomy, respectively. The median follow-up for the entire cohort was 19.5 months. Of the 3 patients (5%) who experienced local failure between 9.2 and 28.5 months after diagnosis, 2 had PET-avid disease in their postoperative cavity and elected for observation before recurrence, and 1 high-risk patient with multifocal disease experienced local failure 2 years after a second radiation course and multiple previous recurrences. Notably, 5 patients did not have any local PET uptake and were observed; none of these patients experienced recurrence. Only 1 grade 3 toxicity was attributed to PET-guided radiation.

CONCLUSIONS

This study examined one of the largest known populations of patients with intracranial meningiomas followed by physicians who used 68Ga-DOTATATE PET-guided therapy. Incorporating 68Ga-DOTATATE PET into future trials may assist with clinician decision making and improve patient outcomes.

How proton therapy fits into the management of adult intracranial tumors

Intracranial tumors include a challenging array of primary and secondary parenchymal and extra-axial tumors which cause neurologic morbidity consequential to location, disease extent, and proximity to critical neurologic structures. Radiotherapy can be used in the definitive, adjuvant, or salvage setting either with curative or palliative intent. Proton therapy (PT) is a promising advance due to dosimetric advantages compared to conventional photon radiotherapy with regards to normal tissue sparing, as well as distinct physical properties, which yield radiobiologic benefits. In this review, the principles of efficacy and safety of PT for a variety of intracranial tumors are discussed, drawing upon case series, retrospective and prospective cohort studies, and randomized clinical trials. This manuscript explores the potential advantages of PT, including reduced acute and late treatment-related side effects and improved quality of life. The objective is to provide a comprehensive review of the current evidence and clinical outcomes of PT. Given the lack of consensus and directives for its utilization in patients with intracranial tumors, we aim to provide a guide for its judicious use in clinical practice.

Dose-Escalated Radiation Therapy Is Associated With Improved Outcomes for High-Grade Meningioma

PURPOSE

The optimal modern radiation therapy (RT) approach after surgery for atypical and malignant meningioma is unclear. We present results of dose escalation in a single-institution cohort spanning 2000 to 2021.

METHODS AND MATERIALS

Consecutive patients with histopathologic grade 2 or 3 meningioma treated with RT were reviewed. A dose-escalation cohort (≥66 Gy equivalent dose in 2-Gy fractions using an α/β = 10) was compared with a standard-dose cohort (<66 Gy). Outcomes were progression-free survival (PFS), cause-specific survival, overall survival (OS), local failure (LF), and radiation necrosis.

RESULTS

One hundred eighteen patients (111 grade 2, 94.1%) were identified; 54 (45.8%) received dose escalation and 64 (54.2%) standard dose. Median follow-up was 45.4 months (IQR, 24.0-80.0 months) and median OS was 9.7 years (Q1: 4.6 years, Q3: not reached). All dose-escalated patients had residual disease versus 65.6% in the standard-dose cohort (P < .001). PFS at 3, 4, and 5 years in the dose-escalated versus standard-dose cohort was 78.9%, 72.2%, and 64.6% versus 57.2%, 49.1%, and 40.8%, respectively, (P = .030). On multivariable analysis, dose escalation (hazard ratio [HR], 0.544; P = .042) was associated with improved PFS, whereas ≥2 surgeries (HR, 1.989; P = .035) and older age (HR, 1.035; P < .001) were associated with worse PFS. The cumulative risk of LF was reduced with dose escalation (P = .016). Multivariable analysis confirmed that dose escalation was protective for LF (HR, 0.483; P = .019), whereas ≥2 surgeries before RT predicted for LF (HR, 2.145; P = .008). A trend was observed for improved cause-specific survival and OS in the dose-escalation cohort (P < .1). Seven patients (5.9%) developed symptomatic radiation necrosis with no significant difference between the 2 cohorts.

CONCLUSIONS

Dose-escalated RT with ≥66 Gy for high-grade meningioma is associated with improved local control and PFS with an acceptable risk of radiation necrosis.

Adjuvant proton beam therapy in patients with grade 2 meningiomas

Background

The World Health Organization (WHO) grade 2 meningiomas behave aggressively with a high proclivity toward recurrence despite maximal surgical resection. Our institution, a pioneer of proton therapy, uses exclusively proton beam radiation, and thus, we present a retrospective cohort analysis of patients with WHO grade 2 meningiomas treated with adjuvant proton beam therapy (PBT) at our institution between 2007 and 2019. The effects of adjuvant PBT were evaluated.

Methods

Data collected include diagnosis, gender, histological subtype, WHO grade, the extent of surgical resection, adjuvant PBT radiation, details of the PBT radiation, recurrence, any additional PBT radiation, systemic medical therapy, and disease-specific survival.

Results

Among the WHO grade 2 meningiomas (n = 50) recommended PBT, 80% and 78% of patients with gross-total resection (GTR) and subtotal resection (STR), respectively, followed through with PBT. The median radiation dose of PBT was 59.5 Gy and 59.92 Gy for patients with GTR and STR, respectively, with a median of 33 fractions delivered in 1.8 Gy doses for both groups. Combined 3-year progression-free survival (PFS) was 96%, and 5-year PFS was 92%. Combined overall survival was 95% at five years. Minimal radiation side effects were reported with no grade 3 or higher toxicities.

Conclusion

Our results suggest that adjuvant PBT is well tolerated with minimal radiation toxicity. Alternative to photon radiation, PBT may be considered at least as safe and effective for adjuvant treatment of WHO grade 2 meningiomas when it is available.

The outcomes measured and reported in intracranial meningioma clinical trials: A systematic review

Background

Meningioma clinical trials have assessed interventions including surgery, radiotherapy, and pharmacotherapy. However, agreement does not exist on what, how, and when outcomes of interest should be measured. To do so would allow comparative analysis of similar trials. This systematic review aimed to summarize the outcomes measured and reported in meningioma clinical trials.

Methods

Systematic literature and trial registry searches were performed to identify published and ongoing intracranial meningioma clinical trials (PubMed, Embase, Medline, CINAHL via EBSCO, and Web of Science, completed January 22, 2022). Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Verbatim outcomes were deduplicated and the resulting unique outcomes were grouped under standardized outcome terms. These were classified using the taxonomy proposed by the "Core Outcome Measures in Effectiveness Trials" (COMET) initiative.

Results

Thirty published articles and 18 ongoing studies were included, describing 47 unique clinical trials: Phase 2 n = 33, phase 3 n = 14. Common interventions included: Surgery n = 13, radiotherapy n = 8, and pharmacotherapy n = 20. In total, 659 verbatim outcomes were reported, of which 84 were defined. Following de-duplication, 415 unique verbatim outcomes remained and were grouped into 115 standardized outcome terms. These were classified using the COMET taxonomy into 29 outcome domains and 5 core areas.

Conclusions

Outcome measurement across meningioma clinical trials is heterogeneous. The standardized outcome terms identified will be prioritized through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a core outcome set for use in future meningioma clinical trials.

Predictors of recurrence after surgical resection of parafalcine and parasagittal meningiomas

PURPOSE

Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery.

METHODS

This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence.

RESULTS

A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10-71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan-Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60-8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16-7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38-6.96; p = 0.006) as independent factors that portend shorter time to recurrence.

CONCLUSION

This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes.

A machine learning-based integrated clinical model for predicting prognosis in atypical meningioma patients

PURPOSE

Atypical meningioma (AM) recurs in up to half of patients after surgical resection and may require adjuvant therapy to improve patient prognosis. Various clinicopathological features have been shown to have prognostic implications in AM, but an integrated prediction model is lacking. Thus, in this study, we aimed to develop and validate an integrated prognostic model for AM.

METHODS

A retrospective cohort of 528 adult AM patients surgically treated at our institution were randomly assigned to a training or validation group in a 7:3 ratio. Sixteen baseline demographic, clinical, and pathological parameters, progression-free survival (PFS), and overall survival (OS) were analysed. Sixty-five combinations of machine learning (ML) algorithms were used for model training and validation to predict tumour recurrence and patient mortality.

RESULTS

The random survival forest (RSF) model was the best model for predicting recurrence and death. Primary or secondary tumour, Ki-67 index, extent of resection, tumour size, brain involvement, tumour necrosis, and age contributed significantly to the model. The C-index value of the RSF recurrence prediction model reached 0.8080. The AUCs for 1-, 3-, and 5-year PFS were 0.83, 0.82, and 0.86, respectively. The C-index value of the RSF death prediction model reached 0.8890. The AUCs for 3-year and 5-year OS were 0.88 and 0.89, respectively.

CONCLUSION

A high-performing integrated RSF predictive model for AM recurrence and patient mortality was proposed that may guide therapeutic decision-making and long-term monitoring.

Targeted gene expression profiling predicts meningioma outcomes and radiotherapy responses

Surgery is the mainstay of treatment for meningioma, the most common primary intracranial tumor, but improvements in meningioma risk stratification are needed and indications for postoperative radiotherapy are controversial. Here we develop a targeted gene expression biomarker that predicts meningioma outcomes and radiotherapy responses. Using a discovery cohort of 173 meningiomas, we developed a 34-gene expression risk score and performed clinical and analytical validation of this biomarker on independent meningiomas from 12 institutions across 3 continents (N = 1,856), including 103 meningiomas from a prospective clinical trial. The gene expression biomarker improved discrimination of outcomes compared with all other systems tested (N = 9) in the clinical validation cohort for local recurrence (5-year area under the curve (AUC) 0.81) and overall survival (5-year AUC 0.80). The increase in AUC compared with the standard of care, World Health Organization 2021 grade, was 0.11 for local recurrence (95% confidence interval 0.07 to 0.17, P < 0.001). The gene expression biomarker identified meningiomas benefiting from postoperative radiotherapy (hazard ratio 0.54, 95% confidence interval 0.37 to 0.78, P = 0.0001) and suggested postoperative management could be refined for 29.8% of patients. In sum, our results identify a targeted gene expression biomarker that improves discrimination of meningioma outcomes, including prediction of postoperative radiotherapy responses.

Spheno-Orbital Meningioma - Treatment Outcomes and Factors Influencing Recurrence

PURPOSE

To determine treatment outcomes, recurrence rates, and predictors of recurrence, to inform future therapeutic approaches for spheno-orbital meningiomas (SOM).

METHODS

A retrospective single-center study of SOM treated from 1990 to 2021 was conducted with comprehensive neuro-ophthalmologic follow-up at Columbia University Medical Center (CUMC). Recurrence requiring reintervention was defined clinically as worsening of visual acuity, visual field defect, or ocular motility after an initial period of stabilization or 6 months of improvement following treatment, or radiologically as either a regrowth with an increase in tumor size by 20% at the site of previous growth or a new region of tumor growth.

RESULTS

In total 46 patients met the inclusion criteria. The mean follow-up was 106 months (range 1-303). Dictated by the phenotype of the disease, patients underwent either gross- (50%), near- (17%), or subtotal resection (26%). Removal of the anterior clinoid process (ACP) was performed in 52% of patients. Nine patients (20%) required an enucleation or exenteration. Radiotherapy was employed at some point of treatment in 50% of cases. Inherited cases (24%) were referred to CUMC for treatment following 1 or more recurrences. The total recurrence rate, including inherited cases, was 54%, occurring at a mean interval of 43 months. The recurrence rate of patients treated solely at CUMC was 40%, occurring at a mean interval of 41 months. A subset of patients (32%) had 2 or more recurrences. Histopathology at the first surgery was WHO grade I (87%) and II (13%) and at the final surgery was WHO grade I (74%), II (21%), and III (4%). A subset of grade I tumors that received radiotherapy (35%) evolved to a higher grade or developed multiple recurrences without a change in histologic grade I. Grade II tumors and treatment with radiotherapy increased the odds of recurrence. Removal of the ACP and gross total resection decreased the odds of recurrence.

CONCLUSION

Due to the routinely long interval to tumor recurrence, lifelong surveillance of patients with SOM is prudent. ACP resection and gross total resection, where possible, reduce tumor recurrence and the need for further treatment. Radiotherapy should be reserved for higher-grade meningiomas and select grade I tumors.

Interdisciplinary Therapeutic Approaches to Atypical and Malignant Meningiomas

Meningiomas have the highest incidence among brain tumors. In contrast to benign tumors that constitute the majority of this tumor entity, the treatment of aggressive meningiomas (WHO Grade 2 and 3) is more challenging, requiring gross total removal of the tumor and the affected dura and adjuvant radiotherapy. Sometimes the location and/or the configuration of the tumor do not favor radical surgical resection without endangering the patient's clinical condition after surgery and pharmacological therapy has, until now, not been proven to be a reliable alternative. Discussion: In this narrative review, we discuss the current literature with respect to the management of meningiomas, discussing the importance of the grade of resection in the overall prognosis of the patient and in the planning of adjuvant therapy. Conclusions: According to the location and size of the tumor, radical resection should be taken into consideration. In patients with aggressive meningiomas, adjuvant radiotherapy should be performed after surgery. In cases of skull base meningiomas, a maximal, though safe, resection should take place before adjuvant therapy. An interdisciplinary approach is beneficial for patients with primary or recurrent meningioma.

Target volume delineation for radiotherapy of meningiomas: an ANOCEF consensus guideline

PURPOSE

Radiotherapy is, with surgery, one of the main therapeutic treatment strategies for meningiomas. No prospective study has defined a consensus for the delineation of target volumes for meningioma radiotherapy. Therefore, target volume definition is mainly based on information from retrospective studies that include heterogeneous patient populations. The aim is to describe delineation guidelines for meningioma radiotherapy as an adjuvant or definitive treatment with intensity-modulated radiation therapy and stereotactic radiation therapy techniques. This guideline is based on a consensus endorsed by a multidisciplinary group of brain tumor experts, members of the Association of French-speaking Neuro-oncologists (ANOCEF).

MATERIALS AND METHODS

A 3-step procedure was used. First, the steering group carried out a comprehensive review to identify divergent issues on meningiomas target volume delineation. Second, an 84-item web-questionnaire has been developed to precisely define meningioma target volume delineation in the most common clinical situations. Third, experts members of the ANOCEF were requested to answer. The first two rounds were completed online. A third round was carried out by videoconference to allow experts to debate and discuss the remaining uncertain questions. All questions remained in a consensus.

RESULTS

Limits of the target volume were defined using visible landmarks on computed tomography and magnetic resonance imaging, considering the pathways of tumor extension. The purpose was to develop clear and precise recommendations on meningiomas target volumes.

CONCLUSION

New recommendations for meningiomas delineation based on simple anatomic boundaries are proposed by the ANOCEF. Improvement in uniformity in target volume definition is expected.

Surgical Management of Meningiomas Involving the Torcula, Transverse Sinus, and Jugular Bulb: A Technical Note and Review of the Literature

Meningiomas that invade the confluens sinuum are rare and require extensive preoperative planning. Here, we describe the surgical and radio-oncological management of an aggressive large occipital meningioma invading the superior sagittal sinus, torcula, right and left transverse sinus down to the level of the jugular bulb in a 21-year-old female patient. Details of the surgical approach are presented to highlight the planned staged resection of this tumor at the level of the torcula to initially debulk the lesion while preserving venous outflow through the patent's sinus. Once the tumor fully occluded the confluens, a second-stage en bloc resection ensued. Postsurgical adjuvant radiation therapy was delivered via fractionated external beam therapy which has provided local control of the tumor since. This case is being discussed in the context of the pertinent literature to demonstrate the highly complex interdisciplinary and staged management of partially intravascular meningiomas involving the major venous sinuses.

Long Term Outcome and Quality of Life of Intracranial Meningioma Patients Treated with Pencil Beam Scanning Proton Therapy

The aim of this study was to assess the clinical outcome, including QoL, of patients with intracranial meningiomas WHO grade 1-3 who were treated with Pencil Beam Scanning Proton Therapy (PBS PT) between 1997 and 2022. Two hundred patients (median age 50.4 years, 70% WHO grade 1) were analyzed. Acute and late side effects were classified according to CTCAE version 5.0. Time to event data were calculated. QoL was assessed descriptively by the EORTC-QLQ-C30 and BN20 questionnaires. With a median follow-up of 65 months (range: 3.8-260.8 months) the 5 year OS was 95.7% and 81.8% for WHO grade 1 and grade 2/3, respectively (p < 0.001). Twenty (10%) local failures were observed. Failures occurred significantly (p < 0.001) more frequent in WHO grade 2 or 3 meningioma (WHO grade 1: n = 7, WHO grade 2/3: n = 13), in patients with multiple meningiomas (p = 0.005), in male patients (p = 0.005), and when PT was initiated not as upfront therapy (p = 0.011). There were no high-grade toxicities in the majority (n = 176; 88%) of patients. QoL was assessed for 83 (41.5%) patients and for those patients PT did not impacted QoL negatively during the follow-up. In summary, we observed very few local recurrences of meningiomas after PBS PT, a stable QoL, and a low rate of high-grade toxicity.

Radiotherapy and radiosurgery for meningiomas

Meningiomas comprise a histologically and clinically diverse set of tumors arising from the meningothelial lining of the central nervous system. In the past decade, remarkable progress has been made in deciphering the biology of these common neoplasms. Nevertheless, effective systemic or molecular therapies for meningiomas remain elusive and are active areas of preclinical and clinical investigation. Thus, standard treatment modalities for meningiomas are limited to maximal safe resection, radiotherapy, or radiosurgery. This review examines the history, clinical rationale, and future directions of radiotherapy and radiosurgery as integral and effective treatments for meningiomas.

Targeted gene expression profiling predicts meningioma outcomes and radiotherapy responses

Background

Surgery is the mainstay of treatment for meningioma, the most common primary intracranial tumor, but improvements in meningioma risk stratification are needed and current indications for postoperative radiotherapy are controversial. Recent studies have proposed prognostic meningioma classification systems using DNA methylation profiling, copy number variants, DNA sequencing, RNA sequencing, histology, or integrated models based on multiple combined features. Targeted gene expression profiling has generated robust biomarkers integrating multiple molecular features for other cancers, but is understudied for meningiomas.

Methods

Targeted gene expression profiling was performed on 173 meningiomas and an optimized gene expression biomarker (34 genes) and risk score (0 to 1) was developed to predict clinical outcomes. Clinical and analytical validation was performed on independent meningiomas from 12 institutions across 3 continents (N = 1856), including 103 meningiomas from a prospective clinical trial. Gene expression biomarker performance was compared to 9 other classification systems.

Results

The gene expression biomarker improved discrimination of postoperative meningioma outcomes compared to all other classification systems tested in the independent clinical validation cohort for local recurrence (5-year area under the curve [AUC] 0.81) and overall survival (5-year AUC 0.80). The increase in area under the curve compared to the current standard of care, World Health Organization 2021 grade, was 0.11 for local recurrence (95% confidence interval [CI] 0.07-0.17, P < 0.001). The gene expression biomarker identified meningiomas benefiting from postoperative radiotherapy (hazard ratio 0.54, 95% CI 0.37-0.78, P = 0.0001) and re-classified up to 52.0% meningiomas compared to conventional clinical criteria, suggesting postoperative management could be refined for 29.8% of patients.

Conclusions

A targeted gene expression biomarker improves discrimination of meningioma outcomes compared to recent classification systems and predicts postoperative radiotherapy responses.

Efficacy of radiotherapy and stereotactic radiosurgery as adjuvant or salvage treatment in atypical and anaplastic (WHO grade II and III) meningiomas: a systematic review and meta-analysis

The role of radiotherapy (RT) and stereotactic radiosurgery (SRS) as adjuvant or salvage treatment in high-grade meningiomas (HGM) is still debated. Despite advances in modern neuro-oncology, HGM (WHO grade II and III) remains refractory to multimodal therapies. Published reports present aggregated data and are extremely varied in population size, exclusion criteria, selection bias, and inclusion of mixed histologic grades, making it extremely difficult to draw conclusions when taken individually. This current work aims to gather the existing evidence on RT and SRS as adjuvants following surgery or salvage treatment at recurrence after multimodality therapy failure and to conduct a systematic comparison between these two modalities. An extensive systematic literature review and meta-analysis were performed. A total of 42 papers were eligible for final analysis (RT n = 27; SRS n = 15) after searching MEDLINE via PubMed, Web-of-science, Cochrane Wiley, and Embase databases. Adjuvant regimens were addressed in 37 papers (RT n = 26; SRS n = 11); salvage regimens were described in 5 articles (RT n = 1; SRS n = 4). The primary outcomes of the study were the overall recurrence rate and mortality. Other actuarial rates (local and distant control, OS, PFS, and complications) were retrieved and analyzed as secondary outcomes. A total of 2853 patients harboring 3077 HGM were included. The majority were grade II (87%) with a mean pre-radiation volume of 8.7 cc. Adjuvant regimen: 2742 patients (76.4% RT; 23.6% SRS) with an overall grade II/III rate of 6.6/1. Lesions treated adjSRS were more frequently grade III (17 vs 12%, p < 0.001), and received subtotal resection (57 vs 27%, p = 0.001) compared to the RT cohort. AdjSRS cohort had a significantly shorter mean follow-up than adjRT (36.7 vs 50.3 months, p = 0.01). The overall recurrence rate was 38% in adjRT vs 25% in adjSRS (p = 0.01), while mortality did not differ between the groups (20% vs 23%, respectively; p = 0.80). The median time to recurrence was 1.5 times longer in the RT group (p = 0.30). Five-year local control was 55% in adjRT and 26% in adjSRS (p = 0.01), while 5-year OS was 73% and 78% (p = 0.62), and 5-year PFS was 62% and 40% in adjRT and adjSRS (p = 0.008). No difference in the incidence of complications (24% vs 14%, p = 0.53). Salvage regimen: 110 patients (37.3% RT; 62.7% SRS) with a grade II/III rate of 8.6/1. The recurrence rate was 46% in salRT vs 24% in salSRS (p = 0.39), time to recurrence was 1.8 times longer in the salRT group (35 vs 18.5 months, p = 0.74). Mortality was slightly yet not significantly higher in salRT (34% vs 12%, p = 0.54). Data on local and distant control were only available for salSRS. The 5-year OS was 49% and 83% (p = 0.90), and the 5-year PFS was 39% and 50% in salRT and salSRS (p = 0.66), respectively. High-grade meningiomas (WHO grade II and III) receiving adjuvant RT showed a higher overall recurrence rate than meningiomas receiving adjuvant SRS. The adjRT cohort, however, achieved higher 5-year LC and PFS rates, thus suggesting a potentially longer time to recurrence compared to adjSRS patients, who, meanwhile, experienced a significantly shorter follow-up. This result must also consider the higher number of grade III lesions and the smaller extent of resection achieved in the adjSRS group. Overall mortality did not differ between the two groups. No differences in outcome measures were observed in salvage regimens.

Impact of a cell cycle and an extracellular matrix remodeling transcriptional signature on tumor progression and correlation with EZH2 expression in meningioma

OBJECTIVE

The authors searched for genetic and transcriptional signatures associated with tumor progression and recurrence in their cohort of patients with meningiomas, combining the analysis of targeted exome, NF2-LOH, transcriptome, and protein expressions.

METHODS

The authors included 91 patients who underwent resection of intracranial meningioma at their institution between June 2000 and November 2007. The search of somatic mutations was performed by Next Generation Sequencing through a customized panel and multiplex ligation-dependent probe amplification for NF2 loss of heterozygosity. The transcriptomic profile was analyzed by QuantSeq 3' mRNA-Seq. The differentially expressed genes of interest were validated at the protein level analysis by immunohistochemistry.

RESULTS

The transcriptomic analysis identified an upregulated set of genes related to metabolism and cell cycle and downregulated genes related to immune response and extracellular matrix remodeling in grade 2 (atypical) meningiomas, with a significant difference in recurrent compared with nonrecurrent cases. EZH2 nuclear positivity associated with grade 2, particularly with recurrent tumors and EZH2 gene expression level, correlated positively with the expression of genes related to cell cycle and negatively to genes related to immune response and regulation of cell motility.

CONCLUSIONS

The authors identified modules of dysregulated genes in grade 2 meningiomas related to the activation of oxidative metabolism, cell division, cell motility due to extracellular remodeling, and immune evasion that were predictive of survival and exhibited significant correlations with EZH2 expression.

Risk Stratification for Management of Solitary Fibrous Tumor/Hemangiopericytoma of the Central Nervous System

INTRODUCTION

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) of the central nervous system (CNS) is a rare meningeal tumor. Given the absence of prospective or randomized data, there are no standard indications for radiotherapy. Recently, the NRG Oncology and EORTC cooperative groups successfully accrued and completed the first prospective trials evaluating risk-adapted adjuvant radiotherapy strategies for meningiomas. Using a similar framework, we sought to develop prognostic risk categories that may predict the survival benefit associated with radiotherapy, using two large national datasets.

METHODS

We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) databases for all newly diagnosed cases of SFT/HPC within the CNS. Risk categories were created, as follows: low risk-grade 1, with any extent of resection (EOR) and grade 2, with gross-total resection; intermediate risk-grade 2, with biopsy/subtotal resection; high risk-grade 3 with any EOR. The Kaplan-Meier method and Cox proportional hazards regressions were used to determine the association of risk categories with overall and cause-specific survival. We then determined the association of radiotherapy with overall survival in the NCDB, stratified by risk group.

RESULTS

We identified 866 and 683 patients from the NCDB and SEER databases who were evaluated, respectively. In the NCDB, the 75% survival times for low- (n = 312), intermediate- (n = 239), and high-risk (n = 315) patients were not reached, 86 months (HR 1.60 (95% CI 1.01-2.55)), and 55 months (HR 2.56 (95% CI 1.68-3.89)), respectively. Our risk categories were validated for overall and cause-specific survival in the SEER dataset. Radiotherapy was associated with improved survival in the high- (HR 0.46 (0.29-0.74)) and intermediate-risk groups (HR 0.52 (0.27-0.99)) but not in the low-risk group (HR 1.26 (0.60-2.65)). The association of radiotherapy with overall survival remained significant in the multivariable analysis for the high-risk group (HR 0.55 (0.34-0.89)) but not for the intermediate-risk group (HR 0.74 (0.38-1.47)). Similar results were observed in a time-dependent landmark sensitivity analysis.

CONCLUSION

Risk stratification based on grade and EOR is prognostic of overall and cause-specific survival for SFT/HPCs of the CNS and performs better than any individual clinical factor. These risk categories appear to predict the survival benefit from radiotherapy, which is limited to the high-risk group and, potentially, the intermediate-risk group. These data may serve as the basis for a prospective study evaluating the management of meningeal SFT/HPCs.

Neurocognitive considerations in the treatment of meningioma with radiation therapy: applications for quantitative neuroimaging and precision radiation medicine

This article focuses on the role of radiotherapy in the management of meningioma, in the definitive and adjuvant setting and across the spectrum of meningioma grade. Treatment paradigms, informed by clinical evidence, are discussed. Notably, we focus on the impact of radiotherapy on normal brain tissues and neurocognitive function, particularly the dose-dependent changes in white matter and cerebral cortex thickness. Novel imaging techniques have allowed the identification of microstructural changes to eloquent white matter, cortex, and subcortical regions as biomarkers for understanding RT-induced changes in cognitive functioning. Deficits in multiple domains including attention, memory, language and executive function can become more pronounced following radiation. Longitudinal assessment with imaging and neurocognitive testing pre- and post-radiation have allowed correlation between dose to specific regions of the brain and decline in associated domains of neurocognitive function. These findings suggest incorporation of areas at higher risk for neurocognitive sequelae into precision radiation planning. Volumetric arc therapy, advanced planning with cortical sparing, proton therapy and stereotactic radiosurgery are reviewed as options for delivering therapeutic dose to target volumes while minimizing risk to adjacent sensitive regions. The treatment of meningioma is an evolving area, with improving outcomes for higher grade disease in modern trials, where care must be taken to maximize both disease control as well as quality of life for patients.

Analysis of recurrence probability following radiotherapy in patients with CNS WHO grade 2 meningioma using integrated molecular-morphologic classification

Background

The current World Health Organization (WHO) classification of brain tumors distinguishes 3 malignancy grades in meningiomas, with increasing risk of recurrence from CNS WHO grades 1 to 3. Radiotherapy is recommended by current EANO guidelines for patients not safely amenable to surgery or after incomplete resection in higher grades. Despite adequately predicting recurrence probability for the majority of CNS WHO grade 2 meningioma patients, a considerable subset of patients demonstrates an unexpectedly early tumor recurrence following radiotherapy.

Methods

A retrospective cohort of 44 patients with CNS WHO grade 2 meningiomas were stratified into 3 risk groups (low, intermediate, and high) using an integrated morphological, CNV- and methylation family-based classification. Local progression-free survival (lPFS) following radiotherapy (RT) was analyzed and total dose of radiation was correlated with survival outcome. Radiotherapy treatment plans were correlated with follow-up images to characterize the pattern of relapse. Treatment toxicities were further assessed.

Results

Risk stratification of CNS WHO grade 2 meningioma into integrated risk groups demonstrated a significant difference in 3-year lPFS following radiotherapy between the molecular low- and high-risk groups. Recurrence pattern analysis revealed that 87.5 % of initial relapses occurred within the RT planning target volume or resection cavity.

Conclusions

Integrated risk scoring can identify CNS WHO grade 2 meningioma patients at risk or relapse and dissemination following radiotherapy. Therapeutic management of CNS WHO grade 2 meningiomas and future clinical trials should be adjusted according to the molecular risk-groups, and not rely on conventional CNS WHO grading alone.

The "Combo" radiotherapy treatment for high-risk grade 2 meningiomas: dose escalation and initial safety and efficacy analysis

PURPOSE

The subgroup "high-risk" WHO grade 2 (hRG2) meningiomas may benefit from adjuvant radiation therapy (RT), but results are still suboptimal with high rates of local progression. A dose escalation using high-conformal RT techniques needs to be evaluated in terms of efficacy and safety. We report the results of a dose-escalation study, named "Combo-RT", combining Intensity Modulated Radiotherapy (IMRT) or Volumetric Arc Therapy (VMAT) with Hypofractionated Stereotactic Radiotherapy (hSRT) boost.

PATIENTS AND METHODS

From November 2015 to January 2019, we prospectively enrolled 16 patients with hRG2. Seven patients had subtotal resection (STR) and 9 patients had a recurrent tumor. All patients received Combo-RT: LINAC-IMRT/ VMAT on the surgical bed and CyberKnife-hSRT boost on residual/recurrent meningioma Toxicity and initial efficacy were evaluated.

RESULTS

The median age was 62 years (range, 31-80 years). The median cumulative dose delivered was 46 Gy For IMRT or VMAT and 15 Gy in 3 fractions at a median isodose line of 77% for hSRT. The median cumulative BED and EQD2 were 108.75 Gy and 72.5 Gy respectively. 3-year-PFS was 75% for the whole cohort,100% for patients with STR, and 55.5% for recurrent patients. Negligible toxicities, and stable or improved symptoms during long-term follow-up were observed. Salvage treatment for recurrence was an independent predictor of treatment failure (P = 0.025).

CONCLUSIONS

With the limitation of a small series of patients, our results suggest that a dose escalation for hRG2 meningiomas, using a Combo-RT approach, is safe and particularly effective in the subgroup of patients with STR. Further studies are warranted.

Post Surgical Management of WHO Grade II Meningiomas: Our Experience, the Role of Gamma Knife and a Literature Review

Purpose: Grade II meningiomas are rarer than Grade I, and when operated on, bear a higher risk of local recurrence, with a 5-year progression free survival (PFS) ranging from 59 to 90%. Radiotherapy (RT) or radiosurgery, such as Gamma Knife radiosurgery (GKRS) can reduce the risk of relapse in patients with residual disease, even if their role, particularly after gross total resection (GTR), is still under debate. Main goal of this study was to compare the outcomes of different post-surgical management of grade II meningiomas, grouped by degree of surgical removal (Simpson Grade); next in order we wanted to define the role of GKRS for the treatment of residual disease or relapse. Methods: from November 2016 to November 2020 all patients harboring grade II meningiomas, were divided into three groups, based on post-surgical management: (1) wait and see, (2) conventional adjuvant radiotherapy and (3) stereotactic GKRS radiosurgery. Relapse rate and PFS were registered at the time of last follow up and results were classified as stable, recurrence next to or distant from the surgical cavity. In the second part of the study we collected data of all patients who underwent GKRS in our Centers from November 2017 to November 2020. Results: A total of 37 patients were recruited, including seven patients with multiple meningiomas. Out of 47 meningiomas, 33 (70.2%) were followed with a wait and see strategy, six (12.7%) were treated with adjuvant radiotherapy, and 8 patients (17.0%) with adjuvant GKRS. Follow up data were available for 43 (91.4%) meningiomas. Within the wait and see group, recurrence rates differed based on Simpson grades, lower recurrence rates being observed in three Simpson I cases (30%) compared to twelve relapses (60%) in patients with Simpson grade II/III. Finally, out of the 24 meningiomas undergoing GKRS (8 residual and 16 recurrence), 21 remained stable at follow up. Conclusions: Gross total resection (GTR) Simpson II and III have a significantly worse outcome as compared to Simpson I. The absence of adjuvant treatment leads to significant worsening of the disease progression curve. Adjuvant radiotherapy, especially GKRS, provides good local control of the disease and should be considered as an adjuvant treatment in all cases where Simpson I resection is not possible.

Health-related quality of life and clinical outcome after radiotherapy of patients with intracranial meningioma

This retrospective, single-institutional study investigated long-term outcome, toxicity and health-related quality of life (HRQoL) in meningioma patients after radiotherapy. We analyzed the data of 119 patients who received radiotherapy at our department from 1997 to 2014 for intracranial WHO grade I-III meningioma. Fractionated stereotactic radiotherapy (FSRT), intensity modulated radiotherapy (IMRT) or radiosurgery radiation was applied. The EORTC QLQ-C30 and QLQ-BN20 questionnaires were completed for assessment of HRQoL. Overall survival (OS) for the entire study group was 89.6% at 5 years and 75.9% at 10 years. Local control (LC) at 5 and 10 years was 82.4% and 73.4%, respectively. Local recurrence was observed in 22 patients (18.5%). Higher grade acute and chronic toxicities were observed in seven patients (5.9%) and five patients (4.2%), respectively. Global health status was rated with a mean of 59.9 points (SD 22.3) on QLQ-C30. In conclusion, radiotherapy resulted in very good long-term survival and tumor control rates with low rates of severe toxicities but with a deterioration of long-term HRQoL.

Radiotherapy for meningiomas

Meningiomas are the most common primary central nervous system neoplasm. Despite promising recent progress in elucidating the genomic landscape and underlying biology of these histologically, molecularly, and clinically diverse tumors, the mainstays of meningioma treatment remain maximal safe resection and radiation therapy. The aim of this review of meningioma radiotherapy is to provide a concise summary of the history, current evidence, and future for application of radiotherapy in meningioma treatment.

Diagnostic and Therapeutic Strategy in Anaplastic (Malignant) Meningioma, CNS WHO Grade 3

Simple Summary

Only 1% of all meningioma diagnosis is classified as malignant (anaplastic) meningioma. Due to their rarity, clinical management of these tumors presents several gaps. In this review, we investigate current knowledge of anaplastic meningioma focusing on their pathological and radiological diagnosis, molecular assessment, and loco-regional and systemic management. Despite the current marginal role of systemic therapy, it is possible that the increasing knowledge of molecular altered pathways of the disease will lead to the development of novel effective systemic treatments.

Abstract

Background: Meningiomas are the most common primary central nervous system malignancies accounting for 36% of all intracranial tumors. However, only 1% of meningioma is classified as malignant (anaplastic) meningioma. Due to their rarity, clinical management of these tumors presents several gaps. Methods: We carried out a narrative review aimed to investigate current knowledge of anaplastic meningioma focusing on their pathological and radiological diagnosis, molecular assessment, and loco-regional and systemic management. Results: The most frequent genetic alteration occurring in meningioma is the inactivation in the neurofibromatosis 2 genes (merlin). The accumulation of copy number losses, including 1p, 6p/q, 10q, 14q, and 18p/q, and less frequently 2p/q, 3p, 4p/q, 7p, 8p/q, and 9p, compatible with instability, is restricted to NF2 mutated meningioma. Surgery and different RT approaches represent the milestone of grade 3 meningioma management, while there is a marginal role of systemic therapy. Conclusions: Anaplastic meningiomas are rare tumors, and diagnosis should be suspected and confirmed by trained radiologists and pathologists. Despite the current marginal role of systemic therapy, it is possible that the increasing knowledge of molecular altered pathways of the disease will lead to the development of novel effective systemic treatments.

Surgical results of 158 petroclival meningiomas with special focus on standard craniotomies

Objective

The goal of this retrospective study is the evaluation of risk factors for postoperative neurological deficits after petroclival meningioma (PCM) surgery with special focus on standard craniotomies.

Materials and methods

One-hundred-fifty-eight patients were included in the study, of which 133 patients suffered from primary and 25 from recurrent PCM. All patients were operated on and evaluated concerning age, tumor size, histology, pre- and postoperative cranial nerve (CN) deficits, morbidity, mortality, and surgical complications. Tumor-specific features—e.g., consistency, surface, arachnoid cleavage, and location—were set in a four-grade classification system that was used to evaluate the risk of CN deficits and tumor resectability.

Results

After primary tumor resection, new CN deficits occurred in 27.3% of patients. Preoperative ataxia improved in 25%, whereas 10% developed new ataxia. Gross total resection (GTR) was achieved in 59.4%. The morbidity rate, including hemiparesis, shunt-dependence, postop-hemorrhage, and tracheostomy was 22.6% and the mortality rate was 2.3%. In recurrent PCM surgery, CN deficits occurred in 16%. GTR could be achieved in three cases. Minor complications occurred in 20%. By applying the proposed new classification system to patients operated via standard craniotomies, the best outcome was observed in type I tumor patients (soft tumor consistency, smooth surface, plane arachnoid cleavage, and unilateral localization) with GTR in 78.7% (p < 0.001) and 11.9% new CN deficits (p = 0.006).

Conclusion

Standard craniotomies as the retrosigmoid or subtemporal/pterional approaches are often used for the resection of PCMs. Whether these approaches are sufficient for GTR—and avoidance of new neurological deficits—depends mainly on the localization and intrinsic tumor-specific features.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-022-04105-5.

Should adjuvant radiotherapy be used in atypical meningioma (WHO grade 2) following gross total resection? A systematic review and Meta-analysis

BACKGROUND

The role of adjuvant radiotherapy (RT) following gross total resection (GTR) in atypical meningioma (AM) is not well established and its benefit remains unclear. We aim to evaluate the survival benefit of adjuvant RT in AM following GTR.

METHODS

We searched biomedical databases for studies published between January 1964-February 2021 and included studies reporting primary outcomes of 5-year PFS, 5-year OS and had survival curves for restricted mean survival time (RMST) calculations. Data extracted from survival curves were pooled and analyzed using a random-effects model. Hazard ratio (HR) was calculated for sensitivity analysis.

RESULTS

We included 12 non-randomized studies comprising 1,078 patients. 803 (74.5%) patients were treated with GTR alone and 275 (25.5%) patients received adjuvant RT. In 9 studies, RT included 3 D conformal RT, intensity modulated RT, or fractionated stereotactic radiotherapy); in 3 studies, stereotactic radiosurgery was also used. Median dose of RT was 59.4 Gy. Adjuvant RT resulted in an increase of 3.9 months for restricted mean PFS truncated at 5 years (95% CI 0.23-7.72; p = 0.037) and a 22% reduction in the hazard of disease progression or death (hazards ratio 0.78; 95% CI 0.46-1.33; p = 0.370). Restricted mean OS, truncated at 5 years, was improved with adjuvant RT by 1.1 months (95% CI 0.37-1.81; p = 0.003) and a 21% reduction in the hazard of death from any cause (HR 0.79; 95% CI 0.51-1.24; p = 0.310). Meta-regression analysis of the RMST of EBRT dose did not reveal any significant difference in PFS or OS between studies reporting median dose of <59.4 Gy vs. ≥ 59.4 Gy.

CONCLUSION

Adjuvant RT following GTR in patients with AM improved restricted mean PFS and OS. While we await the results from ongoing randomized controlled trials, adjuvant RT should be recommended.

An interpretable radiomics model to select patients for radiotherapy after surgery for WHO grade 2 meningiomas

Objectives

This study investigated whether radiomic features can improve the prediction accuracy for tumor recurrence over clinicopathological features and if these features can be used to identify high-risk patients requiring adjuvant radiotherapy (ART) in WHO grade 2 meningiomas.

Methods

Preoperative magnetic resonance imaging (MRI) of 155 grade 2 meningioma patients with a median follow-up of 63.8 months were included and allocated to training (n = 92) and test sets (n = 63). After radiomic feature extraction (n = 200), least absolute shrinkage and selection operator feature selection with logistic regression classifier was performed to develop two models: (1) a clinicopathological model and (2) a combined clinicopathological and radiomic model. The probability of recurrence using the combined model was analyzed to identify candidates for ART.

Results

The combined clinicopathological and radiomics model exhibited superior performance for the prediction of recurrence compared with the clinicopathological model in the training set (area under the curve [AUC] 0.78 vs. 0.67, P = 0.042), which was also validated in the test set (AUC 0.77 vs. 0.61, P = 0.192). In patients with a high probability of recurrence by the combined model, the 5-year progression-free survival was significantly improved with ART (92% vs. 57%, P = 0.024), and the median time to recurrence was longer (54 vs. 17 months after surgery).

Conclusions

Radiomics significantly contributes added value in predicting recurrence when integrated with the clinicopathological features in patients with grade 2 meningiomas. Furthermore, the combined model can be applied to identify high-risk patients who require ART.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02090-7.

Adjuvant Radiotherapy Versus Surveillance for Grade 2 Intracranial Meningiomas: A Multi-Institutional Propensity Score-Matched Study

Purpose

We aimed to compare the outcomes of adjuvant radiotherapy (ART) and surveillance in patients with grade 2 meningiomas (MNG2) who underwent surgical resection.

Materials and Methods

Data from four hospitals, in which patients aged ≥18 years underwent Simpson grade 1−4 surgical resection for newly diagnosed MNG2 between 1998 and 2018, were examined in this multicenter retrospective cohort study. Patients receiving ART with conventional fractionation were compared with those undergoing surveillance. Progression-free survival (PFS), progression/recurrence (P/R) were evaluated.

Results

This study included 518 patients, 158 of whom received ART. The median follow-up duration was 64.9 months. In the total cohort, ART was independently associated with significantly improved PFS (HR, 0.35; 95% CI, 0.23–0.55; P<0.001) and P/R (HR, 0.30; 95% CI, 0.18–0.48; P<0.001). In the propensity score-matched cohort (n=143 in each group), the 5-year PFS rates were 80.8% and 57.7% (P=0.004), and the 5-year P/R rates were 16.5% and 40.0% (P=0.002) in the ART and surveillance groups, respectively. After gross total resection, the 5-year PFS (85.0% vs. 64.7%; P=0.020) and P/R rates (15.2% vs. 32.0%; P=0.035) were significantly better in the ART group than in the surveillance group. A model for P/R was developed using recursive partitioning analysis with surgical extent, tumor size, and Ki-67 index. ART reduced the risk of P/R in the low- (P=0.069), intermediate- (P=0.044), and high-risk groups (P<0.001). Local control was also significantly enhanced by ART among all the risk groups (all P<0.05).

Conclusions

ART significantly improved PFS and P/R in patients with MNG2, irrespective of the surgical extent, and can be recommended after gross total resection. A prognostic model may guide decision-making for the use of ART.

Development of 'Core Outcome Sets' for Meningioma in Clinical Studies (The COSMIC Project): protocol for two systematic literature reviews, eDelphi surveys and online consensus meetings

INTRODUCTION

Meningioma is the most common primary intracranial tumour in adults. The majority are non-malignant, but a proportion behave more aggressively. Incidental/minimally symptomatic meningioma are often managed by serial imaging. Symptomatic meningioma, those that threaten neurovascular structures, or demonstrate radiological growth, are usually resected as first-line management strategy. For patients in poor clinical condition, or with inoperable, residual or recurrent disease, radiotherapy is often used as primary or adjuvant treatment. Effective pharmacotherapy treatments do not currently exist. There is heterogeneity in the outcomes measured and reported in meningioma clinical studies. Two 'Core Outcome Sets' (COS) will be developed: (COSMIC: Intervention) for use in meningioma clinical effectiveness trials and (COSMIC: Observation) for use in clinical studies of incidental/untreated meningioma.

METHODS AND ANALYSIS

Two systematic literature reviews and trial registry searches will identify outcomes measured and reported in published and ongoing (1) meningioma clinical effectiveness trials, and (2) clinical studies of incidental/untreated meningioma. Outcomes include those that are clinician reported, patient reported, caregiver reported and based on objective tests (eg, neurocognitive tests), as well as measures of progression and survival. Outcomes will be deduplicated and categorised to generate two long lists. The two long lists will be prioritised through two, two-round, international, modified eDelphi surveys including patients with meningioma, healthcare professionals, researchers and those in caring/supporting roles. The two final COS will be ratified through two 1-day online consensus meetings, with representation from all stakeholder groups.

ETHICS AND DISSEMINATION

Institutional review board (University of Liverpool) approval was obtained for the conduct of this study. Participant eConsent will be obtained prior to participation in the eDelphi surveys and consensus meetings. The two systematic literature reviews and two final COS will be published and freely available.

TRIAL REGISTRATION NUMBER

COMET study ID 1508.

Postoperative radiotherapy for meningiomas - a decision-making analysis

Background

The management of meningiomas is challenging, and the role of postoperative radiotherapy is not standardized.

Methods

Radiation oncology experts in Swiss centres were asked to participate in this decision-making analysis on the use of postoperative radiotherapy (RT) for meningiomas. Experts from ten Swiss centres agreed to participate and provided their treatment algorithms. Their input was converted into decision trees based on the objective consensus methodology. The decision trees were used as a basis to identify consensus and discrepancies in clinical routine.

Results

Several criteria used for decision-making in postoperative RT in meningiomas were identified: histological grading, resection status, recurrence, location of the tumour, zugzwang (therapeutic need to treat and/or severity of symptoms), size, and cell division rate. Postoperative RT is recommended by all experts for WHO grade III tumours as well as for incompletely resected WHO grade II tumours. While most centres do not recommend adjuvant irradiation for WHO grade I meningiomas, some offer this treatment in recurrent situations or routinely for symptomatic tumours in critical locations. The recommendations for postoperative RT for recurrent or incompletely resected WHO grade I and II meningiomas were surprisingly heterogeneous.

Conclusions

Due to limited evidence on the utility of postoperative RT for meningiomas, treatment strategies vary considerably among clinical experts depending on the clinical setting, even in a small country like Switzerland. Clear majorities were identified for postoperative RT in WHO grade III meningiomas and against RT for hemispheric grade I meningiomas outside critical locations. The limited data and variations in clinical recommendations are in contrast with the high prevalence of meningiomas, especially in elderly individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09607-z.

Long-Term Outcomes for Patients With Atypical or Malignant Meningiomas Treated With or Without Radiation Therapy: A 25-Year Retrospective Analysis of a Single-Institution Experience

Purpose

Atypical (World Health Organization [WHO] grade 2) and malignant (WHO grade 3) meningiomas have high rates of local recurrence, and questions remain about the role of adjuvant radiation therapy (RT) for patients with WHO grade 2 disease. These patients frequently require salvage therapy, and optimal management is uncertain given limited prospective data. We report on the long-term outcomes for patients with atypical and malignant meningiomas treated with surgery and/or RT at our institution.

Methods and Materials

Data were collected through a retrospective chart review for all patients with WHO grade 2 or 3 meningiomas treated with surgery and/or RT at our institution between January 1992 and March 2017. Progression-free survival (PFS) and overall survival (OS) were described using the KaplanMeier estimator. The outcomes in the subgroups were compared with a log-rank test. A Cox proportional hazards model was used for the univariable and multivariable analyses of predictors of PFS.

Results

A total of 66 patients were included in this analysis. The median follow-up was 12.4 years overall and 8.6 years among surviving patients. Fifty-two patients (78.8%) had WHO grade 2 meningiomas, and 14 patients (21.2%) had WHO grade 3 disease. Thirty-six patients (54.5%) were treated with surgery alone, 28 patients (42.4%) with surgery and adjuvant RT, and 2 patients (3%) with RT alone. Median PFS and OS were 3.2 years and 8.8 years, respectively. PFS was significantly improved with adjuvant RT compared with surgery alone (hazard ratio, 0.36; 95% confidence interval, 0.18-0.70). Patients with Ki-67 index >10% showed a trend toward worse PFS compared with patients with Ki-67 ≤10% (hazard ratio, 0.51; 95% confidence interval, 0.25-1.04). No significant differences in PFS or OS were observed with respect to Simpson or WHO grade.

Conclusions

For patients with atypical or malignant meningiomas, adjuvant RT was associated with significantly improved PFS, and Ki-67 index >10% was associated with a trend toward worse PFS. Given the long-term survival, high recurrence rates, and efficacy of salvage therapy, patients with atypical and malignant meningiomas should be monitored systematically long after initial treatment.

Deep learning-based automatic segmentation of meningioma from multiparametric MRI for preoperative meningioma differentiation using radiomic features: a multicentre study

OBJECTIVES

Develop and evaluate a deep learning-based automatic meningioma segmentation method for preoperative meningioma differentiation using radiomic features.

METHODS

A retrospective multicentre inclusion of MR examinations (T1/T2-weighted and contrast-enhanced T1-weighted imaging) was conducted. Data from centre 1 were allocated to training (n = 307, age = 50.94 ± 11.51) and internal testing (n = 238, age = 50.70 ± 12.72) cohorts, and data from centre 2 external testing cohort (n = 64, age = 48.45 ± 13.59). A modified attention U-Net was trained for meningioma segmentation. Segmentation accuracy was evaluated by five quantitative metrics. The agreement between radiomic features from manual and automatic segmentations was assessed using intra class correlation coefficient (ICC). After univariate and minimum-redundancy-maximum-relevance feature selection, L1-regularized logistic regression models for differentiating between low-grade (I) and high-grade (II and III) meningiomas were separately constructed using manual and automatic segmentations; their performances were evaluated using ROC analysis.

RESULTS

Dice of meningioma segmentation for the internal testing cohort were 0.94 ± 0.04 and 0.91 ± 0.05 for tumour volumes in contrast-enhanced T1-weighted and T2-weighted images, respectively; those for the external testing cohort were 0.90 ± 0.07 and 0.88 ± 0.07. Features extracted using manual and automatic segmentations agreed well, for both the internal (ICC = 0.94, interquartile range: 0.88-0.97) and external (ICC = 0.90, interquartile range: 0.78-70.96) testing cohorts. AUC of radiomic model with automatic segmentation was comparable with that of the model with manual segmentation for both the internal (0.95 vs. 0.93, p = 0.176) and external (0.88 vs. 0.91, p = 0.419) testing cohorts.

CONCLUSIONS

The developed deep learning-based segmentation method enables automatic and accurate extraction of meningioma from multiparametric MR images and can help deploy radiomics for preoperative meningioma differentiation in clinical practice.

KEY POINTS

• A deep learning-based method was developed for automatic segmentation of meningioma from multiparametric MR images. • The automatic segmentation method enabled accurate extraction of meningiomas and yielded radiomic features that were highly consistent with those that were obtained using manual segmentation. • High-grade meningiomas were preoperatively differentiated from low-grade meningiomas using a radiomic model constructed on features from automatic segmentation.

Concomitant Temozolomide plus radiotherapy for high-grade and recurrent meningioma: a retrospective chart review

Background

High-grade and recurrent meningiomas are often treatment resistant and pose a therapeutic challenge after surgical and radiation therapy (RT) failure. Temozolomide (TMZ) is a DNA alkylating agent that appears to have a radiosensitizing effect when used in combination with RT and may be worthwhile in meningioma treatment. Thus, we investigated the potential efficacy of concomitant RT plus TMZ compared to historical controls of just RT used in the treatment of high-grade and recurrent meningiomas.

Methods

We performed a retrospective analysis of patients with meningioma treated at the University of Colorado with TMZ chemoradiation. Progression free survival (PFS) and overall survival (OS) were calculated from the start of chemoradiation to local recurrence or death, respectively.

Results

Eleven patients (12 tumors) were treated with chemoradiation with a median follow-up of 41.5 months. There were two WHO grade 1, eight grade 2 and two grade 3 meningiomas. Three patients died during the follow-up period—one being disease related (11.1%). Two patients had meningioma recurrence—at 2.3 months (WHO grade 3), and 5.4 years (WHO grade 2). Three-year OS and PFS for grade 2 meningiomas were each 88%. Historical controls demonstrate a 3-year median OS and PFS of 83% and 75.8%, respectively.

Conclusions

Treatment options are limited for meningiomas after local failure. In this study, TMZ chemoradiation demonstrated no significant difference in PFS and OS in the treatment of grade 2 meningiomas compared to historic controls. Further study is warranted to find novel methods for the treatment of malignant and recurrent meningiomas.

Multisession radiosurgery for grade 2 (WHO), high risk meningiomas. A phase II clinical trial

Purpose

Patients suffering from recurrent and residual grade 2 (WHO) meningiomas after subtotal excision should be considered as high-risk groups with an uncertain prognosis. Adjuvant radiotherapy seems to be the best approach to reduce disease progression. The primary aim of this phase II explorative, monocentric, single arm study was to evaluate the safety of adjuvant multisession radiosurgery (mRS) in this group of patients; the efficacy in terms of tumour local control was the secondary endpoint.

Methods

Patients recruited from April 2017 to May 2019 were over 18 years old, had a histologically-documented intracranial recurrent or residual Grade 2 meningioma (WHO 2016) and a KPS > 70. Patients with NF2, concomitant neoplasm or pregnancy were excluded. Descriptive statistics were provided for categorical variables. Progression free survival (PFS) was modelled using the Kaplan–Meier method.

Results

Twenty-four patients were enrolled. All 24 patients underwent mRS: twenty-two patients received 28 Gy in 4 fractions, 2 patients received 24 Gy in 4 Treatment related adverse events (CTCAE 4.3) were limited to grade 2 in 1 patient (4.1%). At a median follow-up of 28 months, 8 patients (33.3%) had disease progression, either out-of-field or infield, compared with the planning target volume. Considering both infield and out-of-field progressions, 3-year PFS was 47% (95% confidence interval, CI, 22–69%); considering only the infield ones, 3-year PFS was 86% (95% CI 55–96%), and local control at last follow-up was 92%.

Conclusion

mRS provides good local control of the tumour volume (TV) and is associated with a low rate of toxicity. These results call for further investigation to confirm favourable outcomes in patients with high-risk meningioma.

Trial information

NCT05081908, October 18, 2021, retrospectively registered.

Clinical factors and outcomes of malignant meningioma: a population-based study

OBJECTIVE

We aimed to investigate prognostic factors and outcomes of malignant meningioma and to construct a nomogram model of survival.

METHODS

Patients with malignant meningioma were collected from the Surveillance, Epidemiology, and End Results database. The nomogram was developed for the 3-, 5-, and 8-year prediction of overall survival (OS) and cancer-specific survival (CSS). Harrell's concordance index (C-index) and decision curve analysis (DCA) were used to verify the predicted effect of the nomogram.

RESULTS

Between 1998 and 2016, 806 adult patients with histologically confirmed malignant meningioma were included. The mean age at diagnosis was 61.0 years (median 61.0 years), with a range of 19-104 years. Univariate analysis revealed that male gender, distant metastasis, and age ≥ 80 years as significant adverse factors for OS and CSS. These factors remained significance in the multivariate analysis. The nomogram demonstrated satisfactory discrimination, with a C-index value of 0.663 for OS and 0.654 for CSS, respectively. For both OS and CSS, the DCA curves indicated that the nomogram model performed better than other clinical variables.

CONCLUSION

Older age, male gender, distant metastasis, and radiotherapy were significantly related to poor prognosis; and extent of resection did not affect survival.

The Discrepancy Between Standard Histologic WHO Grading of Meningioma and Molecular Profile: A Single Institution Series

Introduction

Meningiomas are the most common primary central nervous system (CNS) tumor. They are most often benign, but a subset of these can behave aggressively. Current World Health Organization (WHO) guidelines classify meningiomas into three grades based on the histologic findings and presence or absence of brain invasion. These grades are intended to guide treatment, but meningiomas can behave inconsistently with regard to their assigned histopathological grade, influencing patient expectations and management. Advanced molecular profiling of meningiomas has led to the proposal of alternative molecular grading schemes that have shown superior predictive power. These include methylation patterns, copy number alterations, and mutually exclusive driver mutations affecting oncogenes, including BAP1, CDKN2A/B, and the TERT promoter, which are associated with particularly aggressive tumor biology. Despite the evident clinical value, advanced molecular profiling methods are not widely incorporated in routine clinical practice for meningiomas.

Objective

To assess the degree of concordance between the molecular profile of meningiomas and the histopathologic WHO classification, the current method of predicting meningioma behavior.

Methods

In a two-year single-institution experience, we used commercially available resources to determine molecular profiles of all resected meningiomas. Copy number aberrations and oncogenic driver mutations were identified and compared with the histopathologic grade.

Results

One hundred fifty-one total meningioma cases were included for analysis (85.4% WHO grade 1, 13.3% WHO grade 2, and 1.3% grade 3). Chromosomal analysis of 124 of these samples showed that 29% of WHO grade 1 tumor featured copy number profiles consistent with higher grade meningioma, and 25% of WHO grade 2 meningiomas had copy number profiles consistent with less aggressive tumors. Furthermore, 8% harbored mutations in TERT, CDKN2A/B, or BAP1 of which 6% occurred in grade 1 meningiomas.

Conclusions

Routine advanced molecular profiling of all resected meningiomas using commercially available resources allowed for identification of a significant number of meningiomas whose molecular profiles were inconsistent with WHO grade. Our work shows the clinical value of integrating routine molecular profiling with histopathologic grading to guide clinical decision making.

Transient Enlargement in Meningiomas Treated with Stereotactic Radiotherapy

Simple Summary

Accurate assessment of treatment efficacy is a prerequisite for the improvement in therapeutic outcomes in clinical trials. However, it is very challenging to accurately track the size of meningiomas after radiotherapy, because of their complex shapes and often slow growth. Measuring the whole tumor volume as opposed to simple diameter measurements to assess treatment efficacy, therefore, is very promising but little is known on expected volumetric changes of meningiomas following radiotherapy. Therefore, in this study, we meticulously investigated volumetric changes in meningiomas following radiotherapy incorporating volumetric measurements from 468 MRI studies and evaluated newly proposed RANO volumetric criteria in the context of radiotherapy. We found that temporary tumor enlargement after radiotherapy overall was rare but occurred significantly more frequently after high than after low single doses of radiation, represented an important differential diagnosis to tumor progression and would have skewed results in a clinical trial if not accounted for.

Abstract

To investigate the occurrence of pseudoprogression/transient enlargement in meningiomas after stereotactic radiotherapy (RT) and to evaluate recently proposed volumetric RANO meningioma criteria for response assessment in the context of RT. Sixty-nine meningiomas (benign: 90%, atypical: 10%) received stereotactic RT from January 2005–May 2018. A total of 468 MRI studies were segmented longitudinally during a median follow-up of 42.3 months. Best response and local control were evaluated according to recently proposed volumetric RANO criteria. Transient enlargement was defined as volumetric increase ≥20% followed by a subsequent regression ≥20%. The mean best volumetric response was −23% change from baseline (range, −86% to +19%). According to RANO, the best volumetric response was SD in 81% (56/69), MR in 13% (9/69) and PR in 6% (4/69). Transient enlargement occurred in only 6% (4/69) post RT but would have represented 60% (3/5) of cases with progressive disease if not accounted for. Transient enlargement was characterized by a mean maximum volumetric increase of +181% (range, +24% to +389 %) with all cases occurring in the first year post-RT (range, 4.1–10.3 months). Transient enlargement was significantly more frequent with SRS or hypofractionation than with conventional fractionation (25% vs. 2%, p = 0.015). Five-year volumetric control was 97.8% if transient enlargement was recognized but 92.9% if not accounted for. Transient enlargement/pseudoprogression in the first year following SRS and hypofractionated RT represents an important differential diagnosis, especially because of the high volumetric control achieved with stereotactic RT. Meningioma enlargement during subsequent post-RT follow-up and after conventional fractionation should raise suspicion for tumor progression.

Opportunities and challenges for the development of "core outcome sets" in neuro-oncology

Core Outcome Sets (COS) define minimum outcomes to be measured and reported in clinical effectiveness trials for a particular health condition/health area. Despite recognition as critical to clinical research design for other health areas, none have been developed for neuro-oncology. COS development projects should carefully consider: scope (how the COS should be used), stakeholders involved in development (including patients as both research partners and participants), and consensus methodologies used (typically a Delphi survey and consensus meeting), as well as dissemination plans. Developing COS for neuro-oncology is potentially challenging due to extensive tumor subclassification (including molecular stratification), different symptoms related to anatomical tumor location, and variation in treatment options. Development of a COS specific to tumor subtype, in a specific location, for a particular intervention may be too narrow and would be unlikely to be used. Equally, a COS that is applicable across a wider area of neuro-oncology may be too broad and therefore lack specificity. This review describes why and how a COS may be developed, and discusses challenges for their development, specific to neuro-oncology. The COS under development are briefly described, including: adult glioma, incidental/untreated meningioma, meningioma requiring intervention, and adverse events from surgical intervention for pediatric brain tumors.

Radiation therapy for atypical and anaplastic meningiomas: an overview of current results and controversial issues

Meningiomas are the most common intracranial tumors. Most meningiomas are WHO grade 1 tumors whereas less than one-quarter of all meningiomas are classified as atypical (WHO grade 2) and anaplastic (WHO grade 3) tumors, based on local invasiveness and cellular features of atypia. Surgical resection remains the cornerstone of meningioma therapy and represents the definitive treatment for the majority of patients; however, grade 2 and grade 3 meningiomas display more aggressive behavior and are difficult to treat. Several retrospective series have shown the efficacy and safety of postoperative adjuvant external beam radiation therapy (RT) for patients with atypical and anaplastic meningiomas. More recently, two phase II prospective trials by the Radiation Therapy Oncology Group (RTOG 0539) and the European Organisation for Research and Treatment of Cancer (EORTC 2042) have confirmed the potential benefits of fractionated RT for patients with intermediate and high-risk meningiomas; however, several issues remain a matter of debate. Controversial topics include the timing of radiation treatment in patients with totally resected atypical meningiomas, the optimal radiation technique, dose and fractionation, and treatment planning/target delineation. Ongoing randomized trials are evaluating the efficacy of early adjuvant RT over observation in patients undergoing gross total resection.

Postoperative Adjuvant Radiotherapy in Atypical Meningioma Patients: A Meta-Analysis Study

Background and Purpose

Consensus regarding the need for adjuvant radiotherapy (RT) in patients with atypical meningiomas (AMs) is lacking. We compared the effects of adjuvant RT after surgery, gross total resection (GTR), and subtotal resection (STR) on progression-free survival (PFS) and overall survival (OS) in patients with AMs, respectively.

Methods

We performed a systematic review and meta-analysis of the literature published in PubMed, Embase, and the Cochrane Library from inception to February 1, 2021, to identify articles comparing the PFS and OS of patients receiving postoperative RT after surgery, GTR and STR.

Results

We identified 2307 unique studies; 24 articles including 3078 patients met the inclusion criteria. The sensitivity analysis results showed that for patients undergoing undifferentiated surgical resection, adjuvant RT reduced tumor recurrence (HR=0.70, p<0.0001) with no significant effect on survival (HR=0.89, p=0.49). Postoperative RT significantly increased PFS (HR=0.69, p=0.01) and OS (HR=0.55, p=0.007) in patients undergoing GTR. The same improvement was observed in patients undergoing STR plus RT (PFS: HR=0.41, p<0.00001; OS: HR=0.47, p=0.01). A subgroup analysis of RT in patients undergoing GTR showed no change in PFS in patients undergoing Simpson grade I and II resection (HR=1.82, p=0.22) but significant improvement in patients undergoing Simpson grade III resection (HR=0.64, p=0.02).

Conclusion

Regardless of whether GTR or STR was performed, postoperative RT improved PFS and OS to varying degrees. Especially for patients undergoing Simpson grade III or IV resection, postoperative RT confers the benefits for recurrence and survival.

Radiotherapy of benign intracranial tumours

We present the updated recommendations of the French Society for Radiation Oncology on benign intracranial tumours. Most of them are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumours. Some grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumours are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumour, or a local relapse. Indications have to be discussed at a multidisciplinary panel, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumours, are commonly realized, to avoid as much a possible the occurrence of late side effects.

A Novel MRI-Based Risk Stratification Algorithm for Predicting Postoperative Recurrence of Meningioma: More Benefits to Patients

Pathological grading of meningioma is insufficient to predict recurrence after resection and to guide individualized treatment strategies. One hundred and thirty-three patients with meningiomas who underwent total resection were enrolled in this retrospective study. Univariate analyses were conducted to evaluate the association between factors and recurrence. Least absolute shrinkage and selection operator (Lasso) was used to further select variables to build a logistic model. The predictive efficiency of the model and WHO grade was compared by using receiver operating characteristic curve (ROC), decision curve analysis (DCA), and net reclassification improvement (NRI). Patients were given a new risk layer based on a nomogram. The recurrence of meningioma in different groups was observed through the Kaplan-Meier curve. Univariate analysis demonstrated that 11 risk factors were associated with prognosis (P < 0.05). The result of ROC proved that the quantified risk-scoring system (AUC = 0.853) had a higher benefit than pathological grade (AUC = 0.689, P = 0.011). The incidence of recurrence of the high risk cohort (69%) was significantly higher than that of the low risk cohort (9%) by Kaplan-Meier analysis (P < 0.001). And all patients who did not relapse in the high risk group received adjuvant radiotherapy. The novel risk stratification algorithm has a significant value for the recurrence of meningioma and can help in optimizing the individualized design of clinical therapy.

Surgical Treatment of Recurrent Spheno-Orbital Meningioma

OBJECTIVE

The extensive bone infiltration and carpet-like growth characteristics of spheno-orbital meningioma (SOM) make it hard to remove entirely, and recurrence and proptosis are the main reasons for reoperation. The authors report 20 cases of surgical treatment for recurrence of SOM, including surgical technique and symptom improvement.

METHODS

The clinical data and follow-up results of 20 cases of recurrent SOM at our institution from 2000 to 2017 were retrospectively analyzed.

RESULTS

All of the 20 patients with recurrence had received at least one operation before admission, with a mean age of 56 years and 70% female. The mean follow-up time was 36 months (1-72 months). All patients mainly showed symptoms such as proptosis and headache, and were found to be affected by supraorbital fissure during the operation. In 17 patients with recurrence, the affected sphenoid wing became tumor-like hyperplasia. Patients with extraocular muscle involvement have obvious protrusion and are often accompanied by diplopia. After surgical removal of the tumor, the symptoms of proptosis in 19 patients were significantly improved. During the follow-up, only 3 cases of proptosis recurred. After 15 patients underwent Simpson grade IV resection, 4 patients (27%) relapsed again. Five patients underwent Simpson III resection, and only 1 patient (20%) had tumor recurrence 18th months after surgery, and no proptosis recurred.

CONCLUSIONS

The complete surgical removal of recurrent SOM is practically impossible. The main direction of surgical treatment should be to improve the symptoms of proptosis.

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.