Distinguishing grade I meningioma from higher grade meningiomas without biopsy

Meningioma grading via diagnostic imaging: A systematic review and meta-analysis

PURPOSE

Meningioma is the most common intracranial tumor, graded on pathology using WHO criteria to predict tumor course and treatment. However, pathological grading via biopsy may not be possible in cases with poor surgical access due to tumor location. Therefore, our systematic review aims to evaluate whether diagnostic imaging features can differentiate high grade (HG) from low grade (LG) meningiomas as an alternative to pathological grading.

METHODS

Three databases were searched for primary studies that either use routine magnetic resonance imaging (MRI) or computed tomography (CT) to assess pathologically WHO-graded meningiomas. Two investigators independently screened and extracted data from included studies.

RESULTS

24 studies met our inclusion criteria with 12 significant (p < 0.05) CT and MRI features identified for differentiating HG from LG meningiomas. Cystic changes in the tumor had the highest specificity (93.4%) and irregular tumor-brain interface had the highest positive predictive value (65.0%). Mass effect had the highest sensitivity (81.0%) and negative predictive value (90.7%) of all imaging features. Imaging feature with the highest accuracy for identifying HG disease was irregular tumor-brain interface (79.7%). Irregular tumor-brain interface and heterogenous tumor enhancement had the highest AUC values of 0.788 and 0.703, respectively.

CONCLUSION

Our systematic review highlight imaging features that can help differentiate HG from LG meningiomas.

Epidemiology, Genetics, and DNA Methylation Grouping of Hyperostotic Meningiomas

BACKGROUND AND OBJECTIVES

Meningiomas are the most common primary intracranial tumors and are among the only tumors that can form lamellar, hyperostotic bone in the tumor microenvironment. Little is known about the epidemiology or molecular features of hyperostotic meningiomas.

METHODS

Using a retrospective database of 342 meningiomas treated with surgery at a single institution, we correlated clinical, tumor-related, targeted next-generation DNA sequencing (n = 39 total, 16 meningioma-induced hyperostosis [MIH]), and surgical variables with the presence of MIH using generalized linear models. Meningioma DNA methylation grouping was analyzed on a separate population of patients from the same institution with preoperative imaging studies sufficient for identification of MIH (n = 200).

RESULTS

MIH was significantly correlated with anterior fossa (44.3% of MIH vs 17.5% of non-MIH were in the anterior fossa P < .001, c2) or skull base location (62.5% vs 38.3%, P < .001, c2) and lower MIB-1 labeling index. Gross total resection was accomplished in 27.3% of tumors with MIH and 45.5% of nonhyperostotic meningiomas (P < .05, t test). There was no association between MIH and histological World Health Organization grade (P = .32, c2). MIH was significantly more frequent in meningiomas from the Merlin-intact DNA methylation group (P < .05). Somatic missense mutations in the WD-repeat-containing domain of the TRAF7 gene were the most common genetic alteration associated with MIH (n = 12 of 15, 80%, P < .01, c2).

CONCLUSION

In this article, we show that MIH has a predilection for the anterior skull base and affected tumors are less amenable to gross total resection. We find no association between MIH and histological World Health Organization grade, but show that MIH is more common in the Merlin-intact DNA methylation group and is significantly associated with TRAF7 somatic missense mutations. These data provide a framework for future investigation of biological mechanisms underlying MIH.

Variability in the Arterial Supply of Intracranial Meningiomas: An Anatomic Study

BACKGROUND AND OBJECTIVES

Intracranial meningiomas are a diverse group of tumors, which vary by grade, genetic composition, location, and vasculature. Expanding the understanding of the supply of skull base (SBMs) and non-skull base meningiomas (NSBMs) will serve to further inform resection strategies. We sought to delineate the vascular supply of a series of intracranial meningiomas by tumor location.

METHODS

A retrospective study of intracranial meningiomas that were studied using preoperative digital subtraction angiograms before surgical resection at a tertiary referral center was performed. Patient, tumor, radiologic, and treatment data were collected, and regression models were developed.

RESULTS

One hundred sixty-five patients met inclusion criteria. The mean age was 57.1 years (SD: 12.6). The mean tumor diameter was 4.9 cm (SD: 1.5). One hundred twenty-six were World Health Organization Grade I, 37 Grade II, and 2 Grade III. Arterial feeders were tabulated by Al-Mefty's anatomic designations. SBMs were more likely to derive arterial supply from the anterior circulation, whereas NSBMs were supplied by external carotid branches. NSBMs were larger (5.61 cm vs 4.45 cm, P = <.001), were more often presented with seizure (20% vs 8%, P = .03), were higher grade ( P = <.001) had more frequent peritumoral brain edema (84.6% vs 66%, P = .04), and had more bilateral feeders (47.7% vs 28%, P = .01) compared with SBMs. More arterial feeders were significantly associated with lower tumor grade ( P = .023, OR = 0.59). Higher tumor grade (Grade II/III) was associated with fewer arterial feeders ( P = .017, RR = 0.74).

CONCLUSION

Meningioma location is associated with specific vascular supply patterns, grade, and patient outcomes. This information suggests that grade I tumors, especially larger tumors, are more likely to have diverse vascular supply patterns, including internal carotid branches. This study may inform preoperative embolization and surgical considerations, particularly for large skull base tumors.

Preoperative Prediction of Intracranial Meningioma Grade Using Conventional CT and MRI

Objective

Preoperative diagnosis of tumor grade can assist in treatment-related decision-making for patients with intracranial meningioma. This study aimed to distinguish between high-grade and low-grade meningiomas using conventional CT and MRI.

Methodology

We retrospectively analyzed 173 consecutive patients with intracranial meningioma (149 low-grade and 24 high-grade tumors) who were treated surgically at the National Hospital Organization Kyushu Medical Center from 2008 to 2020. Clinical and radiological features, including tumor doubling time (Td) and relative growth rate (RGR), were compared between low-grade and high-grade meningiomas.

Results

Multivariate logistic regression analysis showed that symptomatic tumor (p=0.001), non-skull base location (p=0.006), irregular tumor shape (p=0.043), tumor heterogeneity (p=0.025), and peritumoral brain edema (p=0.003) were independent predictors of high-grade meningioma. In 53 patients who underwent surgery because of tumor progression, progression to symptoms (p=0.027), intratumoral heterogeneity (p<0.001), peritumoral brain edema (p=0.001), larger tumor volume (p=0.005), shorter Td (p<0.001), and higher RGR (P<0.001) were significantly associated with high-grade meningioma. Receiver operating characteristics (ROC) curve analysis showed that the optimal Td and annual RGR cut-off values to distinguish high-grade from low-grade meningioma were 460.5 days and 73.2%, respectively (100% sensitivity and 78.6% specificity).

Conclusion

Based on our findings, conventional CT and MRI are useful methods to predict meningioma grades before surgery. High-grade lesions are associated with non-skull base location, irregular tumor shape, intratumoral heterogeneity, and peritumoral brain edema. High-grade meningioma should be suspected in tumors that exhibit Td <460.5 days or annual RGR >73.2% or those that develop intratumoral heterogeneity or surrounding brain edema on surveillance imaging.

Adjuvant radiotherapy for atypical meningiomas is associated with improved progression free survival

PURPOSE

To assess the progression-free survival benefits of adjuvant radiotherapy (ART) following surgical resection compared to surgery alone in high-grade meningioma patients.

METHODS

We retrospectively identified 43 patients with atypical meningiomas, who underwent either radiotherapy post-surgical resection (Surgery+ART) or surgery alone (Surgery alone) at our institution between February 2007 to March 2019. GTR was achieved in 28 patients, and STR, in 11. Patient, meningioma, and treatment data were extracted from records and compared using Kaplan-Meier methodology, log-rank tests, and Cox proportional hazard models. Radiation complications were also evaluated.

RESULTS

Overall 32.6% (n = 14) of patients, 6 patients in the Surgery+ART group and 8 in the Surgery alone group, experienced recurrence. In the Surgery+ART group, the median PFS time was 46.5 months (CI: [35.8-50.6]), compared to 24.5 months (CI: [18.3-32.9]) in the Surgery alone group. 2-year PFS for Surgery+ART was 100% vs. 69.0% for Surgery alone, and the 5-year PFS rate was 70.6% and 39.2%, respectively (log-rank p-value = .004).

CONCLUSIONS

Our data revealed a significant PFS increase for those treated with adjuvant radiotherapy following surgery compared to surgery alone. Future prospective studies evaluating differing radiation modalities and dosages should be conducted.

Demographics and outcomes of meningioma patients treated at a tertiary care center in the Middle East

OBJECTIVE

Meningioma is the most common intracranial primary brain tumor. Risk factors such as age and exposure to radiation as well as prognostic factors such as grade, location, and extent of surgical resection have been reported in the literature worldwide; however, to our knowledge, data from the Middle East is still warranted. In this study, we aim to identify the characteristics, risk factors and outcomes of meningioma patients treated at a multidisciplinary regional referral center in the Middle East.

PATIENTS AND METHODS

This is a retrospective chart review with a prospective follow up of outcomes. It included patients diagnosed with meningioma between January 2005 and December 2015 at the American University of Beirut Medical Center. Patient's demographics, risk factors and outcomes were first retrospectively collected. Then, we conducted phone calls to all included alive patients to update their disease status and outcomes.

RESULTS

One-hundred and ninety-five patients were included. 69 % had grade I tumors and around 31 % with grades II and III meningiomas. The means of the overall survival and progression free survival (PFS) were 198 and 126 months, respectively. The residence area (city vs. countryside), occupation, alcohol use, oral contraceptive use, family history of meningioma, previous head trauma, radiation exposure for head/brain imaging, cell phone use, and finally, the tumor Ki-67 protein level did not correlate with the survival outcomes. The meningioma grade and extent of resection were significant predictors of the PFS on the univariate analysis, whereas, in the multivariate analysis only previous radiotherapy was significant in prolonging PFS.

CONCLUSION

In our study cohort, that included around 30 % grades II and III tumors, previous radiotherapy use was the only significant prognostic factor for longer PFS in patients diagnosed with meningioma. Future prospective studies should be conducted to evaluate genetic and molecular factors that could possibly be linked to meningioma grade and prognosis in our population of Middle Eastern patients.

External beam radiation therapy for meningioma

Radiation therapy (RT) plays an important role in the management of meningioma. Surgery often remains the initial treatment of choice as it reduces mass effect and confirms the diagnosis and grade. However, RT has frequently been successful in the primary setting and is commonly employed as adjuvant therapy for incompletely resected tumors as well as for high-grade meningiomas regardless of resection extent. Some meningiomas develop in locations less amenable to resection or in patients who are poor surgical candidates, in which circumstances RT is particularly appropriate as primary treatment. Recent cooperative group studies including RTOG 0539 have better established the role of RT for meningioma. These studies suggest a role for adjuvant RT for completely resected Grade II meningioma, which was less clear historically. Ongoing clinical trials such as NRG BN 003 and ROAM will further clarify this. This chapter reviews the role of fractionated external beam RT for various grades of meningioma.

Circulating Tumor Biomarkers in Meningiomas Reveal a Signature of Equilibrium Between Tumor Growth and Immune Modulation

Meningiomas are primary central nervous system (CNS) tumors that originate from the arachnoid cells of the meninges. Recurrence occurs in higher grade meningiomas and a small subset of Grade I meningiomas with benign histology. Currently, there are no established circulating tumor markers which can be used for diagnostic and prognostic purposes in a non-invasive way for meningiomas. Here, we aimed to identify potential biomarkers of meningioma in patient sera. For this purpose, we collected preoperative (n = 30) serum samples from the meningioma patients classified as Grade I (n = 23), Grade II (n = 4), or Grade III (n = 3). We used a high-throughput, multiplex immunoassay cancer panel comprising of 92 cancer-related protein biomarkers to explore the serum protein profiles of meningioma patients. We detected 14 differentially expressed proteins in the sera of the Grade I meningioma patients in comparison to the age- and gender-matched control subjects (n = 12). Compared to the control group, Grade I meningioma patients showed increased serum levels of amphiregulin (AREG), CCL24, CD69, prolactin, EGF, HB-EGF, caspase-3, and decreased levels of VEGFD, TGF-α, E-Selectin, BAFF, IL-12, CCL9, and GH. For validation studies, we utilized an independent set of meningioma tumor tissue samples (Grade I, n = 20; Grade II, n = 10; Grade III, n = 6), and found that the expressions of amphiregulin and Caspase3 are significantly increased in all grades of meningiomas either at the transcriptional or protein level, respectively. In contrast, the gene expression of VEGF-D was significantly lower in Grade I meningioma tissue samples. Taken together, our study identifies a meningioma-specific protein signature in blood circulation of meningioma patients and highlights the importance of equilibrium between tumor-promoting factors and anti-tumor immunity.

Factors Associated with Treatment Failure and Radiosurgery-Related Edema in WHO Grade 1 and 2 Meningioma Patients Receiving Gamma Knife Radiosurgery

BACKGROUND

Before the advent of radiosurgery, neurosurgical treatment of meningiomas typically involved gross total resection of the mass whenever surgery was deemed possible. Over the past 4 decades, though, Gamma Knife radiosurgery (GKRS) has proved to be an effective, minimally invasive means to control the growth of these tumors. However, the variables associated with treatment failure (regrowth or clinical progression) after GKRS and GKRS-related complications, such as cerebral edema, are less well understood.

METHODS

We retrospectively collected data between 2009 and 2018 for patients who underwent GKRS for meningiomas. After data collection, we performed univariate and multivariable modeling of the factors that predict treatment failure and cerebral edema after GKRS. Hazard ratios (HR) and P values were determined for these variables.

RESULTS

Fifty-two patients were included our analysis. The majority of patients were female (38/52,73%), and nearly all patients presented with a suspected or confirmed World Health Organization grade 1 meningioma (48/52, 92%). The median tumor volume was 3.49 cc (range, 0.22-20.11 cc). Evidence of meningioma progression after treatment developed in 5 patients (10%), with a median time to continued tumor growth of 5.9 months (range, 2.7-18.3 months). In multivariable analysis, patients in whom treatment failed were more likely to be male (HR = 8.42, P = 0.045) and to present with larger tumor volumes (HR = 1.27, P = 0.011). In addition, 5 patients (10%) experienced treatment-related cerebral edema. On univariate analysis, patients who experienced cerebral edema were more likely present with larger tumors (HR = 1.16, P = 0.028).

CONCLUSIONS

Increasing meningioma size and male gender predispose to meningioma progression after treatment with GKRS. Increasing tumor size also predicts the development of postradiosurgery cerebral edema.

Diagnostic accuracy of diffusion weighted MRI in differentiating benign and malignant meningiomas

Objective

To determine the diagnostic accuracy of DWI in differentiating benign and malignant meningiomas keeping histopathology as gold standard.

Methods

This was a descriptive analytical study conducted at Radiology Department, DUHS/Dr. Ruth K. M. Pfau Civil Hospital Karachi, from August 2016 to March 2018.It included152 patients clinically suspected of meningioma on conventional neuroimaging. Imaging features of DWI were compared with histopathology findings. The diagnostic accuracy of DWI was calculated in terms of sensitivity, specificity, accuracy, PPV and NPV using histopathology as gold standard.

Results

There were 59 male and 93 female patients with mean age of 55.38±9.8 years. Mean duration of sign and symptoms was 5.67±2.57 months. Out of 152 patients, 117(77%) and 35(23%) were differentiated into benign and malignant meningiomas respectively by DWI while 135(88.82%) and17(11.18%) patients were diagnosed respectively on histopathology. The sensitivity, specificity, PPV, NPV and accuracy of DWI of 84.4%, 82.3%, 97.4%, 40%, and 84.2% respectively keeping histopathology as gold standard.

Conclusion

DWI features along with calculation of ADC values is a reliable non-invasive technique for differentiating benign and malignant meningiomas. However the low negative predictive value necessitates the use of histopathology.

The significance of preoperative hematological inflammatory markers in patients with meningiomas

OBJECTIVE

This study was designed to evaluate whether preoperative hematological inflammatory markers would be useful in predicting the pathological grade of meningiomas.

PATIENTS AND METHODS

A retrospective study of 944 patients with newly diagnosed meningioma was conducted. Preoperative blood results were obtained, including platelet, leukocyte, neutrophil, lymphocyte, and monocyte counts, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), albumin level, globulin level, and albumin-to-globulin ratio (AGR). Logistic regression analysis was performed to identify the independent predictive factors for high-grade meningiomas.

RESULTS

Univariate logistic regression analysis indicated that the hematological inflammatory markers associated with tumor grade were leukocyte, neutrophil, and monocyte counts and the LMR (P < 0.05 for all). Multivariate logistic regression analysis showed that high leukocyte count (P = 0.007) and low LMR (P = 0.041) were independent predictive factors for high-grade meningiomas.

CONCLUSIONS

Preoperative high leukocyte count and low LMR were independent predictive factors of high-grade meningiomas, suggesting that leukocyte count and LMR could be useful in the assessment of the grade of meningiomas.

Assessment of intracranial meningioma-associated calcifications using susceptibility-weighted MRI

PURPOSE

To determine the diagnostic accuracy of susceptibility-weighted MRI (SW-MRI) for the detection of intracranial meningioma-associated calcifications compared with standard MR sequences, using computed tomography (CT) as a reference standard.

MATERIALS AND METHODS

354 patients, who had received both a CT and a 1.5 Tesla clinical brain MRI with SW-MRI sequences between January 2014 and July 2016, were retrospectively evaluated and 316 patients were included. Calcification diameter was used to assess correlation between imaging modalities. Sensitivity and specificity as well as intra- and interobserver agreement were calculated for SW-MRI and standard MRI sequences when compared with reference standard CT.

RESULTS

Fifty patients had positive findings for intracranial meningioma-associated calcifications on CT scans. SW-MRI reached a sensitivity of 94% (95% confidence interval [CI]: 83-99%) and a specificity of 95% (95% CI: 92-98%) for the detection of meningioma-associated calcifications, while standard MRI yielded a sensitivity of 64% (95% CI: 49-77%) and a specificity of 94% (95% CI: 90-96%). Diameter measurements between SW-MRI and CT showed a close correlation (R²  = 0.99; P < 0.001) with a slight overestimation of size, which, however, did not reach significance level (SW-MRI: 8.2 mm ± 7.1; CT: 6.8 mm ± 6.4; P = 0.29). Compared with standard MRI, SW-MRI showed a better interobserver agreement for size measurements of calcifications.

CONCLUSION

SW-MRI enables a reliable detection of intracranial meningioma-associated calcifications by using CT as a reference and offers a higher diagnostic accuracy than standard MRI.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1177-1186.