Surgical Outcome of Treating Grades II and III Meningiomas: A Report of 32 Cases

Recurrence of atypical and anaplastic intracranial Meningiomas: A meta-analysis of risk factors

BACKGROUND

The predictive role of multiple risk factors for intracranial atypical and anaplastic meningioma recurrence is convoluted. This meta-analysis assessed the predictive value of selected factors for recurrence in these Meningiomas.

METHODS

Studies encompassing risk factor data including gross total resection (GTR), subtotal resection (STR), post-op radiotherapy, Ki-67 % index >3 %, and location were searched for in PubMed, Embase, and Web of Science, and thereafter analyzed using robust Bayesian meta-analysis.

RESULTS

Eighteen observational studies involving 1589 patients met inclusion criteria for analysis. GTR was identified as a good prognostic factor for recurrence (OR = 0.212; 95 % CI (-1.972, -1.002); heterogeneity BF=0.702), and STR had a significantly higher risk of recurrence (OR = 4.43; 95 % CI 0.658-2.011; heterogeneity BF=0.724). Post-operative radiotherapy did not statistically significantly affect the recurrence process (OR = 1.02; 95 % CI (-1.848, 0.626); heterogeneity (BF=1.034)). Ki67 % index >3 % had an augmented chance of recurrence (OR = 2.38; 95 % CI (-0.220, 2.355); heterogeneity (BF=1.162)). A meta-regression analysis showed that WHO grade III Meningiomas had a higher chance of recurring than grade II Meningiomas.

CONCLUSION

Among the selected factors, STR and Ki67 % index > 3 % were associated with a higher risk of recurrence, with post-operative radiotherapy making no difference. GTR appeared to inversely impact recurrence. Compared to grade II, grade III Meningiomas had higher odds of recurring.

Automated volumetry of meningiomas in contrast-enhanced T1-Weighted MRI using deep learning

BACKGROUND

Meningiomas are among the most common intracranial tumors. In these tumors, volumetric assessment is not only important for planning therapeutic intervention but also for follow-up examination.However, a highly accurate automated volumetric method for meningiomas using single-modality magnetic resonance imaging (MRI) has not yet been reported. Here, we aimed to develop a deep learning-based automated volumetry method for meningiomas in MRI and investigate its accuracy and potential clinical applications.

METHODS

For deep learning, we used MRI images of patients with meningioma who were referred to Osaka University Hospital between January 2007 and October 2020. Imaging data of eligible patients were divided into three non-overlapping groups: training, validation, and testing. The model was trained and tested using the leave-oneout cross-validation method. Dice index (DI) and root mean squared percentage error (RMSPE) were measured to evaluate the model accuracy. Result: A total of 178 patients (64.6 ± 12.3 years [standard deviation]; 147 women) were evaluated. Comparison of the deep learning model and manual segmentation revealed a mean DI of 0.923 ± 0.051 for tumor lesions. For total tumor volume, RMSPE was 9.5 ± 1.2%, and Mann-Whitney U test did not show a significant difference between manual and algorithm-based measurement of the tumor volume (p = 0.96).

CONCLUSION

The automatic tumor volumetry algorithm developed in this study provides a potential volume-based imaging biomarker for tumor evaluation in the field of neuroradiological imaging, which will contribute to the optimization and personalization of treatment for central nervous system tumors in the near future.

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

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

Surgical strategies for intracranial meningioma in the molecular era

INTRODUCTION

Surgical resection has long been the treatment of choice for meningiomas and is considered curative in many cases. Indeed, the extent of resection (EOR) remains a significant factor in determining disease recurrence and outcome optimization for patients undergoing surgery. Although the Simpson Grading Scale continues to be widely accepted as the measure of EOR and is used to predict symptomatic recurrence, its utility is under increasing scrutiny. The influence of surgery in the definitive management of meningioma is being re-appraised considering the rapid evolution of our understanding of the biology of meningioma.

DISCUSSION

Although historically considered "benign" lesions, meningioma natural history can vary greatly, behaving with unexpectedly high recurrence rates and growth which do not always behave in accordance with their WHO grade. Histologically confirmed WHO grade 1 tumors may demonstrate unexpected recurrence, malignant transformation, and aggressive behavior, underscoring the molecular complexity and heterogeneity.

CONCLUSION

As our understanding of the clinical predictive power of genomic and epigenomic factors matures, we here discuss the importance of surgical decision-making paradigms in the context of our rapidly evolving understanding of these molecular features.

Rare magnetic resonance imaging findings of intracranial solitary fibrous tumor: A case report

RATIONALE

Solitary fibrous tumor (SFT) is a rare mesenchymal spindle cell tumor. SFT in the central nervous system (CNS) is rare. This case reports rare magnetic resonance imaging (MRI) findings of intracranial SFT (ISFT).

PATIENT CONCERNS

We report a 47-year-old female patient who was found to have weakness in her right limb with walking instability 2 months before the visit.

DIAGNOSES

Based on imaging, the provisional diagnosis was meningioma. Postsurgical histopathological diagnosis confirmed World Health Organization (WHO) grade I SFT/hemangiopericytoma (HPC).

INTERVENTIONS

The lesion was totally excised. The patient improved remarkably after the operation, without any signs of associated limb movement disorder.

OUTCOMES

No local recurrence or metastases were observed in the follow-up 3 months after the surgery.

LESSONS

Intracranial SFT is a rare mesenchymal tumor. Due to different tumor components, imaging manifestations are diverse and lack of characteristics, so preoperative diagnosis is challenging. Our case provides a rare ISFT with significantly decreased signal intensity in T2 weighted images (T2WI), which is an important supplement to the rare imaging findings of intracranial SFT.

A collision tumor of solitary fibrous tumor/hemangiopericytoma and meningioma: A case report with literature review

An intracranial collision tumor is a rare lesion composed of two histologically different neoplasms in the same anatomic location. Even more rare is the collision tumor of a solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma. The patient was a 46-year-old woman who had a 40 × 35 × 30-mm mass in the vermis of the cerebellum. Histologically, the mass consisted of two different components. One component showed the morphology of meningioma (World Health Organization (WHO) grade I), and the other component exhibited small round cell proliferation with hypercellular density, which was revealed to be SFT/HPC (WHO grade III) based on STAT6 immunohistochemistry. STAT6 showed completely different immunohistochemistry results in these two components (nuclear-negative in meningioma and nuclear-positive in SFT/HPC). Since these two neoplasms are associated with different prognoses, they should be distinguished from each other. When meningioma and an SFT/HPC-like lesion are identified morphologically, it is important to recognize the presence of such a collision tumor composed of meningioma and SFT/HPC, and identify the SFT/HPC component by employing STAT6 immunohistochemistry.

Clear cell histology portends a worse prognosis than other WHO grade II histologies

PURPOSE

Clear cell meningioma (CCM) is a rare WHO grade II meningioma variant, characterized by aggressive features and a high tumor recurrence rate. In this study, we compared overall and progression-free survivals between CCMs and other WHO grade II meningiomas.

METHODS

A retrospective institutional database review was performed to identify all patients who underwent surgical resection of a WHO grade II meningioma between 1997 and 2019. Overall survival and progression-free survival were compared between patients with clear cell meningiomas and patients with other WHO grade II meningiomas. Multivariable Cox proportional-hazards analysis was used to identify independent predictors of tumor recurrence and survival.

RESULTS

We included a total of 214 patients in this study (43 CCMs, 171 other WHO grade II meningiomas). Patients with CCMs had significantly shorter progression-free (p = 0.001) and overall (p = 0.026) survivals than patients with other grade II meningiomas. In multivariable analysis, clear cell histology was a significant and powerful independent predictor of tumor recurrence (HR 1.93; 95% CI 1.14-3.26) when controlling for tumor location, extent of resection, and adjuvant radiation. In multivariable analysis, clear cell histology correlated with increased mortality (HR 1.96, 95% CI 0.97-3.94), though this was not statistically significant.

CONCLUSION

This is the first study to compare overall and progression-free survivals between CCMs and other WHO grade II meningiomas. Clear cell histology predicts a higher risk of tumor recurrence and mortality than other grade II histologies. Future studies may help to understand the impact of these findings and the treatment implications.

Basis for Immunotherapy for Treatment of Meningiomas

Meningiomas are common tumors that account for approximately one third of CNS tumors diagnosed every year. They are classified by the World Health Organization in grades I-III. Higher grades have an increased rate of growth, invasiveness, rate of recurrence, and worse outcomes than lower grades. Most meningiomas are grade I, while ~18% of meningiomas are grade II and III in hospital-based series. Meningiomas are typically "benign" tumors that are treated with surgery and radiation. However, when they recur or are unresectable, treatment options are very limited, especially since they are chemotherapy-resistant. Recent advances in the treatment of cancers with immunotherapy have focused on checkpoint blockade as well as other types of immunotherapy. There is emerging evidence supporting the use of immunotherapy as a potentially effective treatment strategy for meningioma patients. The immune microenvironment of meningiomas is a complex interplay of genetic alterations, immunomodulatory protein expression, and tumor-immune cell interactions. Meningiomas are known to be infiltrated by immune cells including microglia, macrophages, B-cells, and T-cells. Several mechanisms contribute to decreased an ti-tumor immune response, allowing tumor growth and evasion of the immune system. We discuss the most current knowledge on the immune micro-environment of meningiomas, preclinical findings of immunotherapy in meningiomas, meningioma immunotherapy clinical trials, and also offer insight into future prospects for immunotherapies in meningiomas.

Volumetric growth rates of meningioma and its correlation with histological diagnosis and clinical outcome: a systematic review

INTRODUCTION

Tumour growth has been used to successfully predict progression-free survival in low-grade glioma. This systematic review sought to establish the evidence base regarding the correlation of volumetric growth rates with histological diagnosis and potential to predict clinical outcome in patients with meningioma.

METHODS

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Databases were searched for full text English articles analysing volumetric growth rates in patients with a meningioma.

RESULTS

Four retrospective cohort studies were accepted, demonstrating limited evidence of significantly different tumour doubling rates and shapes of growth curves between benign and atypical meningiomas. Heterogeneity of patient characteristics and timing of volumetric assessment, both pre- and post-operatively, limited pooled analysis of the data. No studies performed statistical analysis to demonstrate the clinical utility of growth rates in predicting clinical outcome.

CONCLUSION

This systematic review provides limited evidence in support of the use of volumetric growth rates in meningioma to predict histological diagnosis and clinical outcome to guide future monitoring and treatment.