Trends in Management of Intracranial Meningiomas: Analysis of 49,921 Cases from Modern Cohort

Surgical Risk in Elderly Patients with Meningiomas in Japan

Background/Objective: No guidelines indicate surgical risk factors for the elderly because of the lack of data from general neurosurgeons. To better understand the management of surgical risk in elderly patients with meningiomas based on a national database in Japan. Methods: Results of surgically treated meningiomas were explored in 8138 patients registered in the Diagnosis Procedure Combination database in Japan during 2010-2015. Age (<65, 65-74, and ≥75 years), sex, Barthel index (BI), medical history, tumor location, oral medication prescriptions on admission, and stroke complications were evaluated. Multivariate logistic regression analysis identified risk factors for stroke complications, BI deterioration between admission and discharge, and in-hospital mortality. Results: Advanced age was the prominent risk factor for BI deterioration (odds ratio: 3.26; 95% confidence interval: 2.69-3.95) but not for in-hospital mortality. Lower BI (60-80) on admission increased the risk of BI deterioration in all age groups; however, BI < 60 demonstrated a significant inverse risk (0.47; 0.32-0.69) in the elderly (≥75 years). Location (falx, parasagittal, and deep) and anticoagulants were not significant risk factors for BI deterioration in patients aged ≥ 75 years, despite being significant risk factors in patients aged <65 and/or 65-74 years. Conclusions: Although advanced age could lead to postoperative functional decline at discharge, it was not sufficiently significant enough to be associated with in-hospital mortality. Because of the possibility of recovery even in elderly patients with severe disabilities, appropriate surgical selection and optimal management may lead to favorable functional outcomes in elderly patients with meningiomas.

A semi-automatic segmentation method for meningioma developed using a variational approach model

BACKGROUND

Meningioma is the commonest primary brain tumour. Volumetric post-contrast magnetic resonance imaging (MRI) is recognised as gold standard for delineation of meningioma volume but is hindered by manual processing times. We aimed to investigate the utility of a model-based variational approach in segmenting meningioma.

METHODS

A database of patients with a meningioma (2007-2015) was queried for patients with a contrast-enhanced volumetric MRI, who had consented to a research tissue biobank. Manual segmentation by a neuroradiologist was performed and results were compared to the mathematical model, using a battery of tests including the Sørensen-Dice coefficient (DICE) and JACCARD index. A publicly available meningioma dataset (708 segmented T1 contrast-enhanced slices) was also used to test the reliability of the model.

RESULTS

49 meningioma cases were included. The most common meningioma location was convexity (n = 15, 30.6%). The mathematical model segmented all but one incidental meningioma, which failed due to the lack of contrast uptake. The median meningioma volume by manual segmentation was 19.0 cm3 (IQR 4.9-31.2). The median meningioma volume using the mathematical model was 16.9 cm3 (IQR 4.6-28.34). The mean DICE score was 0.90 (SD = 0.04). The mean JACCARD index was 0.82 (SD = 0.07). For the publicly available dataset, the mean DICE and JACCARD scores were 0.90 (SD = 0.06) and 0.82 (SD = 0.10), respectively.

CONCLUSIONS

Segmentation of meningioma volume using the proposed mathematical model was possible with accurate results. Application of this model on contrast-enhanced volumetric imaging may help reduce work burden on neuroradiologists with the increasing number in meningioma diagnoses.

Nomogram for predicting cardiovascular disease mortality in patients with meningioma: a competing risk analysis

Cancer patients may have increased risk of cardiovascular mortality than general population. We designed this study to investigate the incidence and risk factors of cardiovascular mortality in meningioma patients. Meningioma patients recorded in Surveillance Epidemiology and End Results (SEER) database between 2004 and 2016 were eligible for this study. The standardized mortality ratio (SMR) was calculated to present the relative risk of cardiovascular mortality (ICD-10 codes I00-I99) in meningioma patients compared with general population. Fine-Gray subdistribution proportional hazards regression was performed to identify risk factors of cardiovascular mortality and construct nomogram for predicting cardiovascular-specific survival in meningioma patients. Among 94,067 meningioma patients included in this study, 6145 (6.5%) and 16549 (17.6%) patients died due to cardiovascular diseases and other causes, respectively. The cardiovascular disease-related SMR of included meningioma patients was 25.31 compared with the general population. Results of multivariate competing risk analysis showed that age, male gender, race, marital status, insurance status, tumor size, tumor location, histologic type, and surgery options were risk factors of cardiovascular mortality. The C-index of our constructed nomogram for predicting cardiovascular specific survival was 0.730 (0.712-0.748) and 0.726 (0.696-0.756) in training cohort and validation cohort, respectively. Incorporating demographic and clinical variables, the nomogram we constructed is effective in predicting cardiovascular mortality in meningioma patients and could guide physicians to reasonably control clinical risk factors of cardiovascular mortality in meningioma patients.

Incidence, management, and outcome of incidental meningioma: what has happened in 10 years?

PURPOSE

The aim of this study was to study the use of brain scanning, and the subsequent findings of presumed incidental meningioma in two time periods, and to study differences in follow-up, treatment, and outcome.

METHODS

Records of all performed CT and MRI of the brain during two time periods were retrospectively reviewed in search of patients with presumed incidental meningioma. These patients were further analyzed using medical health records, with the purpose to study clinical handling and outcome during a 3 year follow up.

RESULTS

An identical number of unique patients underwent brain imaging during the two time periods (n = 22 259 vs. 22 013). In 2018-2019, 25% more incidental meningiomas were diagnosed compared to 2008-2009 (n = 161 vs. 129, p = 0.052). MRI was used more often in 2018-2019 (26.1 vs. 12.4%, p = 0.004), and the use of contrast enhancement, irrespective of modality, also increased (26.8 vs. 12.2%, p < 0.001). In the most recent cohort, patients were older (median 79 years vs. 73 years, p = 0.03). Indications showed a significant increase of cancer without known metastases among scanned patients. 29.5 and 35.4% of patients in the cohorts were deceased 3 years after diagnosis for causes unrelated to their meningioma.

CONCLUSIONS

Despite the same number of unique patients undergoing brain scans in the time periods, there was a trend towards more patients diagnosed with an incidental asymptomatic meningioma in the more recent years. This difference may be attributed to more contrast enhanced scans and more scans among the elderly but needs to be further studied. Patients in the cohort from 2018 to 2019 more often had non-metastatic cancer, with their cause of scan screening for metastases. There was no significant difference in management decision at diagnosis, but within 3 years of follow up significantly more patients in the latter cohort had been re-scanned. Almost a third of all patients were deceased within 3 years after diagnosis, due to causes other than their meningioma.

Brain meningioma incidentally detected on a bone scan: A Case report

Incidental meningioma is defined as a mass diagnosed radiologically on MRI and CT scans without histopathological confirmation. In occasional cases, meningiomas can be diagnosed incidentally by bone scintigraphy. This article presents an interesting case where a 44-year-old lady with known breast cancer was found to have a brain meningioma, incidentally, detected on a bone scan, which was initially suspected to be metastatic brain changes. The follow-up MRI and histopathological studies confirmed the diagnosis of meningioma.

Stereotactic Radiosurgery for Intracranial Meningiomas

Meningiomas are thought to originate from the meningothelial cells of the arachnoid mater and are the most common primary brain tumor in adults. Histologically confirmed meningiomas occur with an incidence of 9.12/100,000 population and account for 39% of all primary brain tumors and 54.5% of all non-malignant brain tumors. Risk factors for meningioma include age 65 years and older, female gender, African-American race, history of exposure to head and neck ionizing radiation, and certain genetic disorders such as neurofibromatosis II. Intracranial meningiomas are the most commonly benign, WHO Grade I neoplasms. Atypical and anaplastic are considered malignant lesions.

Imaging score for differentiation of meningioma grade

PURPOSE

We sought to establish a comprehensive imaging score indicating the likelihood of higher WHO grade meningiomas pre-operatively.

METHODS

All surgical intracranial meningioma patients at our institution between 2014 and 2018 underwent retrospective chart review. Preoperative MRI sequences were reviewed, and imaging features were included in the score based on statistical and clinical significance. Point values for each significant feature were assigned based on the beta coefficients obtained from multivariate analysis. The imaging score was calculated by adding up the points, for a total score of 0 to 5. The predictive ability of the score to identify higher-grade meningiomas was evaluated.

RESULTS

Ninety patients, 50% of whom had a postoperative diagnosis of WHO grade II meningioma, were included. The mean age for the population was 59.9 years and 70% were female. Tumor volume ≥ 36.0 cc was assigned 2 points, presence of irregular tumor borders was assigned 2 points, and presence of peritumoral edema was assigned 1 point. The probability of having a WHO grade II meningioma was 0% with a score of 0, 25.0% with a score of 1, 38.5% with a score of 2, 65.4% with a score of 3, and 83.3% with a score of 4 or greater. A threshold of ≥ 3 points achieved a recall of 0.80, precision of 0.73, F1-score of 0.77, accuracy of 0.76, and AUC of 0.82.

CONCLUSION

The proposed imaging scoring system had good predictive capability for WHO grade II meningiomas with good discrimination and calibration. External validation is needed.

Supervised machine learning algorithms demonstrate proliferation index correlates with long-term recurrence after complete resection of WHO grade I meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor, and resection is a mainstay of treatment. It is unclear what duration of imaging follow-up is reasonable for WHO grade I meningiomas undergoing complete resection. This study examined recurrence rates, timing of recurrence, and risk factors for recurrence in patients undergoing a complete resection (as defined by both postoperative MRI and intraoperative impression) of WHO grade I meningiomas.

METHODS

The authors conducted a retrospective, single-center study examining recurrence risk for adult patients with a single intracranial meningioma that underwent complete resection. Uni- and multivariate nominal logistic regression and Cox proportional hazards analyses were performed to identify variables associated with recurrence and time to recurrence. Two supervised machine learning algorithms were then implemented to confirm factors within the cohort that were associated with recurrence.

RESULTS

The cohort consisted of 823 patients who met inclusion criteria, and 56 patients (6.8%) had recurrence on imaging follow-up. The median age of the cohort was 56 years, and 77.4% of patients were female. The median duration of head imaging follow-up for the entire cohort was 2.7 years, but for the subgroup of patients who had a recurrence, the median follow-up was 10.1 years. Estimated 1-, 5-, 10-, and 15-year recurrence-free survival rates were 99.8% (95% confidence interval [CI] 98.8%-99.9%), 91.0% (95% CI 87.7%-93.6%), 83.6% (95% CI 78.6%-87.6%), and 77.3% (95% CI 69.7%-83.4%), respectively, for the entire cohort. On multivariate analysis, MIB-1 index (odds ratio [OR] per 1% increase: 1.34, 95% CI 1.13-1.58, p = 0.0003) and follow-up duration (OR per year: 1.12, 95% CI 1.03-1.21, p = 0.012) were both associated with recurrence. Gradient-boosted decision tree and random forest analyses both identified MIB-1 index as the main factor associated with recurrence, aside from length of imaging follow-up. For tumors with an MIB-1 index < 8, recurrences were documented up to 8 years after surgery. For tumors with an MIB-1 index ≥ 8, recurrences were documented up to 12 years following surgery.

CONCLUSIONS

Long-term imaging follow-up is important even after a complete resection of a meningioma. Higher MIB-1 labeling index is associated with greater risk of recurrence. Imaging screening for at least 8 years in patients with an MIB-1 index < 8 and at least 12 years for those with an MIB-1 index ≥ 8 may be needed to detect long-term recurrences.

Gamma Knife radiosurgery for meningiomas of the confluence of the falx and tentorium

PURPOSE

Meningiomas arising from the confluence of the falx and tentorium (CFT) are a rare and challenging subset of meningiomas. Gamma Knife radiosurgery (GKRS) is well-established as a safe and effective management strategy for intracranial meningiomas, but its role in treating CFT meningiomas is not well-described. This paper reports the largest series focused exclusively on the outcomes of GKRS for CFT meningiomas.

METHODS

We retrospectively identified 20 CFT meningiomas out of 2031 meningioma patients who underwent GKRS at our institution between 1987 and 2021. Tumor control, overall survival (OS), and complications were recorded and analyzed. The median tumor margin dose was 13 Gy at the 50% isodose line. The median tumor volume treated was 4.4 cc (IQR 3.5-7.7). The median patient age was 58 years (range 33-83), the median MRI surveillance duration was 59 months (IQR 34-92), and the median overall follow-up duration was 92 months (IQR 42-201).

RESULTS

The local tumor control rate (PFS) at 5 and 10-years were 100% (N=10) and 83% (N=4), respectively. Eight patients had stable tumor volumes and 11 patients had regression. One patient with a twice-operated tumor had delayed progression at 7.5 years and was retreated with GKRS. No patient had adverse radiation effects during the period of MRI surveillance. The 5 and 10-year OS were 100% (N=13) and 100% (N=7), respectively.

CONCLUSIONS

GKRS is a valuable therapeutic strategy for patients with newly diagnosed CFT meningiomas or progressive residual tumors after surgical resection.

Tumor doubling time as preoperative predictor of malignancy and recurrence in newly diagnosed meningioma

Most meningiomas are benign, and the indications for surgery are determined by size and symptoms, but some are malignant and have a high recurrence rate. Currently, no preoperative prognostic factors have been established. The purpose of this study was to investigate whether tumor doubling time (Td) is useful in predicting tumor prognosis. Patients who underwent surgery for newly diagnosed meningioma at our hospital between 2007 and 2021 with preoperative magnetic resonance (MR) imaging evaluation over a period of 6 months were included in this study. We calculated the Td from the preoperative MR images and examined the correlation between Td and WHO grade, MIB-1 SI, and other conditions. A total of 269 newly diagnosed meningiomas were operated on during the study period, of which 62 met inclusion criteria. The median Td was 1082 days (54-8579 days), and MIB-1 SI was 2.45% (0.7-14.6%). Td and MIB-1 SI had a negative correlation (r =  - 0.319, p = 0.0122). MIB-1 SI was higher in patients with Td < 3 years than in those with Td ≥ 3 (p = 0.005), and the incidence of high WHO grade (grade2) was higher in patients with Td < 1 year than in patients with Td ≥ 1 (p = 0.014). Meningiomas with Td < 3 years had significantly higher MIB-1 SI, and tumors with Td < 1 year had a higher likelihood of malignancy. Therefore, early treatment should be considered in patients with short Td meningioma even if asymptomatic, and further consideration could be given to radical resection at the time of surgery.

The Patient’s Perspective on Proton Radiotherapy of Skull Base Meningioma: A Retrospective Cross-Sectional Survey

Background

Radiotherapy plays an important role in the management of skull base meningioma. The aim of the study was to investigate patient-reported outcomes.

Methods

A questionnaire of 20 items was sent to 192 patients with meningioma of the skull base who have been treated with proton therapy at a single institution. The survey included dichotomous, scaling, and open questions about symptoms, social distancing, rehabilitation, work, reintegration, limitations in recreational activities, as well as daily life activities and correlating diagnoses. Additionally, symptoms were reported retrospectively by the patients at different time points. In total, 128 patients (66.7%) responded. The median age at the time of RT was 55 years (range: 28-91); the majority were female (79%). The median time between the treatment of meningioma and the survey was 38.5 months (range: 7-100).

Results

The most common initial symptoms were visual impairment (N=54, 42.2%), dizziness (N=38, 29.7%), and double vision (N=32, 25%). The most limiting symptom in daily life at the time of the survey was fatigue (N=31, 24.2%); a significant proportion of patients reported depression as associated with diagnosis (31.3%). Only 53% of patients reported occupational activity before treatment, this number did not increase with time. Only N= 40 (31.3%) and N=35 (27.3%) patients reported no limitations in daily household chores or recreational activities by the disease and treatment. The course of cognitive function after treatment showed a temporary deterioration with subsequent improvement. Except for the improvement in emotional functioning, most domains showed a temporary deterioration during radiotherapy, still, the values reached after 6 months differed weekly or moderately from the initial values.

Conclusion

Besides neurological deficits, patients with skull base meningioma experience a variety of unspecific symptoms, which can be most limiting in daily life. Even successful treatment does not necessarily translate into the alleviation of those symptoms. A greater focus on the characterization of those symptom complexes is necessary. Greater focus on functional structures such as the hippocampus might improve the results. Due to the retrospective character, this study is hypothesis-generating.

Plasma concentration of Bisphenol A and leptin in patients with meningioma and glioma: A pilot study

PURPOSE

Recent increase in incidence of meningiomas suggests the need to search for new risk factors. Leptin, a potentially pro-angiogenic and proliferative agent, could be a candidate for this role, as its expression correlates with body mass index (BMI). Because development of meningioma has also been linked to sex hormones, bisphenol A (BPA), a known xenoestrogen, can also be taken into consideration as a potential risk factor. The aim of this study was to determine plasma concentrations of both substances in patients with meningiomas and to match it to patients with gliomas - a group of brain tumors less hormone- and BMI-dependent.

MATERIALS & METHODS

Concentrations of BPA and leptin were measured in plasma of 24 patients with low grade meningioma and in 29 patients with glioma, using gas chromatography-mass spectrometry (GC-MS) and ELISA kits, respectively. The concentrations of both substances in patients with neoplasms were interpreted in relation to their concentration in healthy population, published in recent reports.

RESULTS

Free and conjugated BPA were present in both meningioma and glioma patients. Moreover, their concentrations far exceeded those reported in the healthy population. Nevertheless, the level of leptin revealed to be significantly higher in meningioma patients than in glioma patients.

CONCLUSIONS

Occurrence of both meningioma and glioma may be accompanied by increased concentrations of leptin and BPA. Further large-scale studies are needed to clarify whether the presence of both substances may play a role in pathogenesis or influence clinical course in patients with brain neoplasms.

Epidemiology of Male Hypogonadism

The epidemiology of male hypogonadism has been understudied. Of the known causes of endogenous androgen deficiency, only Klinefelter syndrome is common with a likely population prevalence of greater than 5:10,000 men (possibly as high as 10-25:10,000). Mild traumatic injury might also be a common cause of androgen deficiency (prevalence 5-10:10,000 men), but large, long-term studies must be completed to confirm this prevalence estimation that might be too high. The classic causes of male androgen deficiency-hyperprolactinemia, pituitary macroadenoma, endogenous Cushing syndrome, and iron overload syndrome-are rare (prevalence < 10,000 men).

External validation and recalibration of an incidental meningioma prognostic model - IMPACT: protocol for an international multicentre retrospective cohort study

INTRODUCTION

Due to the increased use of CT and MRI, the prevalence of incidental findings on brain scans is increasing. Meningioma, the most common primary brain tumour, is a frequently encountered incidental finding, with an estimated prevalence of 3/1000. The management of incidental meningioma varies widely with active clinical-radiological monitoring being the most accepted method by clinicians. Duration of monitoring and time intervals for assessment, however, are not well defined. To this end, we have recently developed a statistical model of progression risk based on single-centre retrospective data. The model Incidental Meningioma: Prognostic Analysis Using Patient Comorbidity and MRI Tests (IMPACT) employs baseline clinical and imaging features to categorise the patient with an incidental meningioma into one of three risk groups: low, medium and high risk with a proposed active monitoring strategy based on the risk and temporal trajectory of progression, accounting for actuarial life expectancy. The primary aim of this study is to assess the external validity of this model.

METHODS AND ANALYSIS

IMPACT is a retrospective multicentre study which will aim to include 1500 patients with an incidental intracranial meningioma, powered to detect a 10% progression risk. Adult patients ≥16 years diagnosed with an incidental meningioma between 1 January 2009 and 31 December 2010 will be included. Clinical and radiological data will be collected longitudinally until the patient reaches one of the study endpoints: intervention (surgery, stereotactic radiosurgery or fractionated radiotherapy), mortality or last date of follow-up. Data will be uploaded to an online Research Electronic Data Capture database with no unique identifiers. External validity of IMPACT will be tested using established statistical methods.

ETHICS AND DISSEMINATION

Local institutional approval at each participating centre will be required. Results of the study will be reported through peer-reviewed articles and conferences and disseminated to participating centres, patients and the public using social media.

Nonmalignant meningioma and vestibular schwannoma incidence trends in the United States, 2004-2017

BACKGROUND

Given concerns about risks associated with the growing use of mobile phones over recent decades, the authors analyzed temporal trends in incidence rates of nonmalignant meningioma and vestibular schwannoma in the United States.

METHODS

The incidence of nonmalignant meningioma and vestibular schwannoma among adults in the Surveillance, Epidemiology, and End Results 18 registries during 2004 through 2017 was evaluated according to the method of diagnosis: microscopically (MC) or radiographically confirmed (RGC). Annual percent changes (APCs) and 95% CIs were estimated using log-linear models.

RESULTS

Overall meningioma rates (n = 108,043) increased significantly from 2004 to 2009 (APC, 5.4%; 95% CI, 4.4%-6.4%) but subsequently rose at a slower pace through 2017 (APC, 1.0%; 95% CI, 0.6%-1.5%). Rates for MC meningiomas changed little from 2004 to 2017 (APC, -0.3%; 95% CI, -0.7%, 0.1%) but rose rapidly for RGC meningiomas until 2009 (APC, 9.5%; 95% CI, 7.8%-11.1%) and rose more modestly thereafter (APC, 2.3%; 95% CI, 1.5%-3.0%). Overall vestibular schwannoma rates (n = 17,475) were stable (APC, 0.4%; 95% CI, -0.2%, 1.0%), but MC vestibular schwannoma rates decreased (APC, -1.9%; 95% CI, -2.7%, -1.1%), whereas RGC vestibular schwannoma rates rose (2006-2017: APC, 1.7%; 95% CI, 0.5%-3.0%). For each tumor, the trends by diagnostic method were similar for each sex and each racial/ethnic group, but RGC diagnosis was more likely in older patients and for smaller tumors. Meningioma trends and the proportion of RGC diagnoses varied notably by registry.

CONCLUSIONS

Overall trends obscured differences by diagnostic method in this first large, detailed assessment, but the recent stable rates argue against an association with mobile phone use. Variation among registries requires evaluation to improve the registration of these nonmalignant tumors.

LAY SUMMARY

The etiology of most benign meningiomas and vestibular schwannomas is poorly understood, but concerns have been raised about whether mobile phone use contributes to risk of developing these tumors. Descriptive studies examining temporal trends could provide insight; however, globally, few registries collect these nonmalignant cases. In the United States, reporting benign meningiomas and vestibular schwannomas became required by law in 2004. This was the first large, systematic study to quantify and characterize incidence trends for meningioma and vestibular schwannoma according to whether the tumors were diagnosed microscopically or only radiographically. Differential trends across registries and by diagnostic method suggest that caution should be used when interpreting the patterns.

An International Multicenter Matched Cohort Analysis of Incidental Meningioma Progression During Active Surveillance or After Stereotactic Radiosurgery: The IMPASSE Study

BACKGROUND

The optimal management of patients with an incidental meningiomas remains unclear. The aim of this study was to characterize the radiologic and neurological outcomes of expectant and SRS management of asymptomatic meningioma patients.

METHODS

Using data from 14 centers across 10 countries, the study compares SRS outcomes to active surveillance of asymptomatic meningiomas. Local tumor control of asymptomatic meningiomas and development of new neurological deficits attributable to the tumor were evaluated in the SRS and conservatively managed groups.

RESULTS

In unmatched cohorts, 727 meningioma patients underwent SRS and were followed for a mean of 57.2 months. In the conservatively managed cohort, 388 patients were followed for a mean of 43.5 months. Tumor control was 99.0% of SRS and 64.2% of conservatively managed patients (p<0.001; OR 56.860 (95%CI 26.253-123.150))). New neurological deficits were 2.5% in the SRS and 2.8% of conservatively managed patients (p=0.764; OR 0.890 (95% CI 0.416-1.904)). After 1:1 propensity matching for patient age, tumor volume, location, and imaging follow-up, tumor control in the SRS and conservatively managed cohorts was 99.4% and 62.1%, respectively (p<0.001; OR 94.461 (95% CI 23.082-386.568)). In matched cohorts, new neurological deficits were noted in 2.3% of SRS treated and 3.2% of conservatively managed patients (p=0.475; OR 0.700 (95% CI 0.263-1.863)).

CONCLUSIONS

SRS affords superior radiologic tumor control compared to active surveillance without increasing the risk of neurological deficits in asymptomatic meningioma patients. While SRS and active surveillance are reasonable options, SRS appears to alter the natural history of asymptomatic meningiomas including tumor progression in the majority of patients treated.

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section

BACKGROUND

The optimal management of petroclival meningiomas (PCMs) continues to be debated along with several controversies that persist.

METHODS

A task force was created by the EANS skull base section along with its members and other renowned experts in the field to generate recommendations for the management of these tumors. To achieve this, the task force reviewed in detail the literature in this field and had formal discussions within the group.

RESULTS

The constituted task force dealt with the existing definitions and classifications, pre-operative radiological investigations, management of small and asymptomatic PCMs, radiosurgery, optimal surgical strategies, multimodal treatment, decision-making, and patient's counselling.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the management of PCMs.

High-grade meningiomas in octogenarian and elderly patients: A population-based SEER analysis

Knowledge on high-grade meningiomas in octogenarian and elderly patients is limited. We aimed to analyze the outcomes and identify factors that influence overall survival (OS) in this population, using data from the Surveillance, Epidemiology, and End Results (SEER) database.Patients (≥80 years old) diagnosed with high-grade meningiomas between 1990 and 2016 were retrieved from the SEER database. According to treatments received, patients were classified into three groups: observation, radiation only, and surgery (with or without radiation). A Cox proportional hazards regression model was used for univariate and multivariate analyses. Based on the inclusion criteria, 678 patients with high-grade meningiomas were included.Surgery was the most common treatment modality. The median OS was 32 months for patients who received surgery, compared with 20 months for observation (p = 0.001).The factors significantly associated with OS on multivariate analysis included increasing age (hazard ratio [HR] 1.353, p < 0.001), diagnosis after 2008 (HR 0.693, p = 0.022), and surgical treatment (HR 0.807, p = 0.028). Further analysis revealed increasing age (HR 1.451, p = 0.003), and subtotal resection (HR 1.275, p = 0.043) were significantly associated with worse OS following surgery. This is the largest clinical study of high-grade meningiomas in octogenarian and elderly patients conducted thus far. Age, treatment modality, and year of diagnosis were associated with OS in octogenarian and elderly patients with high-grade meningiomas. Patients who received subtotal resection had a worse prognosis than gross total resection.

Aggressive Progression of a WHO Grade I Meningioma of the Posterior Clinoid Process: An Illustration of the Risks Associated With Observation of Skull Base Meningiomas

Benign, small, and asymptomatic World Health Organization grade I meningiomas are usually managed expectantly with surveillance imaging with the assumption that they are predictably slowing growing. In this paper, we report the case of an incidentally discovered small, right-sided posterior clinoid meningioma in a 53-year-old female. The tumor was managed conservatively but an annual surveillance magnetic resonance imaging demonstrated that the meningioma had an unexpected significant growth impinging on the brainstem, requiring surgical resection and radiosurgery for residual tumor. Despite histopathological confirmation of a grade I meningioma, the tumor recurred significantly and incurred substantial neurological deficits, requiring further surgery and radiotherapy. This report illustrates the potential pitfall for expectant management of small meningiomas in anatomically precarious locations and draws attention to the need for detailed informed discussions with patients regarding the management of these tumors.

In-Hospital Complications After Surgery in Elderly Patients with Asymptomatic or Minor Symptom Meningioma: A Nationwide Registry Study

BACKGROUND

Asymptomatic or minor symptom meningiomas (AMSMs) in the elderly are incidental findings, with no consensus reached on the optimal management strategy. In the present study, we aimed to determine the surgical risk factors for elderly patients with AMSMs using a nationwide registry database in Japan.

METHODS

We identified patients with surgically treated AMSMs using the Diagnosis Procedure Combination database from 2010 to 2015 and reviewed the medical records for age (<65 years; pre-elderly, 65-74 years; and elderly, ≥75 years), sex, Barthel index (BI) score, medical history, tumor location, and complications. An AMSM was defined by a BI score of 100 points at admission. The risk factors for all stroke complications, BI deterioration at discharge, and in-hospital mortality were determined using multivariate logistic regression analyses.

RESULTS

From a total of 10,535 patients with meningioma, 6628 were included. Advanced age was a significant risk factor (odds ratio, 3.54; 95% confidence interval, 2.80-4.46) for BI deterioration but not for all-stroke complications or in-hospital mortality. Midline and posterior fossa tumors, diabetes mellitus, and chronic heart disease were significant risk factors for in-hospital mortality.

CONCLUSIONS

For elderly patients with surgically treated AMSMs, advanced age was a prominent risk factor for functional decline at discharge. Our study identified several factors that should be evaluated before proceeding with surgery for AMSMs in elderly and pre-elderly patients. These findings could, not only improve decision-making among clinicians treating patients with AMSMs, but also help in predicting the results of surgery for elderly patients with AMSMs.

Nation-wide Brain Tumor Registry-based Study of Intracranial Meningioma in Japan: Analysis of Surgery-related Risks

Although surgical resection is the most preferred treatment for intracranial meningiomas, a detailed analysis of the surgery-related risks based on large population data has not been conducted to date. In this study, we analyzed the nation-wide brain tumor registry to assess the surgical risk factors for intracranial meningiomas to provide information for an optimal treatment strategy. Data of 4081 meningioma patients who underwent initial resection between 2001 and 2008 were extracted from the Brain Tumor Registry of Japan (BTRJ) database and reviewed for postoperative mortality, aggravation of Karnofsky Performance Score (KPS), and complications. The total in-hospital mortality rate was 0.59%. Male sex and tumor size ≥30 mm were independent risk factors for mortality. Among 4081 cases, 4.4% of patients had KPS that were lowered by 20 or more points at the time of discharge after surgery. Age ≥65 years, higher WHO grading, tumor location at the skull base, tumor size ≥30 mm, and non-gross total resections were associated with lowering of KPS scores by 20 or more points. The overall incidence of surgical complications was 19.3%. The rate of occurrence of new postoperative seizure in patients with supratentorial meningioma was 10.9%. All complications except for vascular complications occurred with significantly lower frequencies in asymptomatic patients than in symptomatic patients. Our results provide useful information regarding the surgical risks when surgical intervention is being considered for intracranial meningiomas. Surgery is an important option for asymptomatic meningiomas as the mortality rate and complication rate in the current study were sufficiently low.

Initial Gamma Knife Radiosurgery for Large or Documented Growth Asymptomatic Meningiomas: Long-Term Results From a 27-Year Experience

Objective

The aims of this study were to investigate the long-term outcomes of initial Gamma Knife radiosurgery (GKRS) for large (≥20 mm) or documented growth asymptomatic meningiomas.

Design and Methods

This was a single-center retrospective study. Fifty-nine patients with large (≥20 mm) or documented growth asymptomatic meningiomas undergoing initial GKRS were enrolled. The median age was 56 (range, 27–83) years. The median time of follow-up was 66.8 (range, 24.6–245.6) months, and the median tumor margin dose was 13.0 Gy (range, 11.6–22.0 Gy).

Results

Tumors shrunk in 35 patients (59.3%) and remained stable in 23 (39.0%). One patient (1.7%) experienced radiological progression at 54 months after GKRS. The PFS was 100%, 97%, and 97% at 3, 5, and 10 years, respectively. Nine patients (15.3%) occurred new neurological symptoms or signs at a median time of 8.1 (range, 3.0–81.6) months. The symptom PFS was 90% and 78% at 5 and 10 years, respectively. Fifteen patients (25.4%) occurred peritumoral edema (PTE) at a median time of 7.2 (range, 2.0–81.6) months. One patient underwent surgical resection for severe PTE. In univariate and multivariate analysis, Only tumor size (≥25 mm) and maximum dose (≥34 Gy) were significantly associated with PTE [hazard ratio (HR)= 3.461, 95% confidence interval (CI)=1.157-10.356, p=0.026 and HR=3.067, 95% CI=1.068-8.809, P=0.037, respectively].

Conclusions

In this study, initial GKRS can provide a high tumor control rate as well as an acceptable rate of complications in large or documented growth asymptomatic meningiomas. GKRS may be an alternative initial treatment for asymptomatic meningiomas.

PET imaging of meningioma with 18F-FLT: a predictor of tumour progression

We have previously reported that PET with 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) provides a non-invasive assessment of cell proliferation in vivo in meningiomas. The purpose of this prospective study was to evaluate the potential of 18F-FLT PET in predicting subsequent tumour progression in asymptomatic meningiomas. Forty-three adult patients harbouring 46 MRI-presumed (n = 40) and residual meningiomas from previous surgery (n = 6) underwent a 60-min dynamic 18F-FLT PET scan prior to radiological surveillance. Maximum and mean tumour-to-blood ratios (TBRmax, TBRmean) of tracer radioactivity were calculated. Tumour progression was defined according to the latest published trial end-point criteria for bidimensional (2D) and corresponding yet exploratory volumetric measurements from the Response Assessment of Neuro-Oncology (RANO) workgroup. Independent-sample t-test, Pearson correlation coefficient, Cox regression, and receiver operating characteristic (ROC) curve analyses were used whenever appropriate. The median follow-up time after 18F-FLT PET imaging was 18 months (range 5–33.5 months). A high concordance rate (91%) was found with regard to disease progression using 2D-RANO (n = 11) versus volumetric criteria (n = 10). Using 2D-RANO criteria, 18F-FLT uptake was significantly increased in patients with progressive disease, compared to patients with stable disease (TBRmax, 5.5 ± 1.3 versus 3.6 ± 1.1, P &lt; 0.0001; TBRmean, 3.5 ± 0.8 versus 2.4 ± 0.7, P &lt; 0.0001). ROC analysis yielded optimal thresholds of 4.4 for TBRmax [sensitivity 82%, specificity 77%, accuracy 78%, and area under curve (AUC) 0.871; P &lt; 0.0001] and 2.8 for TBRmean (sensitivity 82%, specificity 77%, accuracy 78%, AUC 0.848; P = 0.001) for early differentiation of patients with progressive disease from patients with stable disease. Upon excluding patients with residual meningioma or patients with stable disease with less than 12 months follow-up, the thresholds remained unchanged with similar diagnostic accuracies. Moreover, positive correlations were found between absolute and relative tumour growth rates and 18F-FLT uptake (r &lt; 0.513, P &lt; 0.015) that remained similar when excluding patients with residual meningioma or patients with stable disease and shorter follow-up period. Diagnostic accuracies were slightly inferior at 76% when assessing disease progression using volumetric criteria, while the thresholds remained unchanged. Multivariate analysis revealed that TBRmax was the only independent predictor of tumour progression (P &lt; 0.046), while age, gender, baseline tumour size, tumour location, peritumoural oedema, and residual meningioma had no influence. The study reveals that 18F-FLT PET is a promising surrogate imaging biomarker for predicting subsequent tumour progression in treatment-naïve and asymptomatic residual meningiomas.

Determining the role of adjuvant radiotherapy in the management of meningioma: a Surveillance, Epidemiology, and End Results analysis

OBJECTIVEThe aim of this study was to illustrate the demographic characteristics of meningioma patients and observe the effect of adjuvant radiation therapy on survival by using the Surveillance, Epidemiology, and End Results (SEER) database. More specifically, the authors aimed to answer the question of whether adjuvant radiotherapy following resection of atypical meningioma confers a cause-specific survival benefit. Additionally, they attempted to add to previous characterizations of the epidemiology of primary meningiomas and assess the effectiveness of the standard of care for benign and anaplastic meningiomas. They also sought to characterize the efficacy of various treatment options in atypical and anaplastic meningiomas separately since nearly all other analyses have grouped these two together despite varying treatment regimens for these behavior categories.METHODSSEER data from 1973 to 2015 were queried using appropriate ICD-O-3 codes for benign, atypical, and anaplastic meningiomas. Patient demographics, tumor characteristics, and treatment choices were analyzed. The effects of treatment were examined using a multivariate Cox proportional hazards model and Kaplan-Meier survival analysis.RESULTSA total of 57,998 patients were included in the analysis of demographic, meningioma, and treatment characteristics. Among this population, cases of unspecified WHO tumor grade were excluded in the multivariate analysis, leaving a total of 12,931 patients to examine outcomes among treatment paradigms. In benign meningiomas, gross-total resection (HR 0.289, p = 0.013) imparted a significant cause-specific survival benefit over no treatment. In anaplastic meningioma cases, adjuvant radiotherapy imparted a significant survival benefit following both subtotal (HR 0.089, p = 0.018) and gross-total (HR 0.162, p = 0.002) resection as compared to gross-total resection alone. In atypical tumors, gross-total resection plus radiotherapy did not significantly change the hazard risk (HR 1.353, p = 0.628) compared to gross-total resection alone. Similarly, it was found that adjuvant radiation did not significantly benefit survival after a subtotal resection (HR 1.440, p = 0.644).CONCLUSIONSThe results of this study demonstrate that the role of adjuvant radiotherapy, especially after the resection of atypical meningioma, remains somewhat unclear. Thus, given these results, prospective randomized clinical studies are warranted to provide clear information on the effects of adjuvant radiation in meningioma treatment.

Trends in the utilization of radiotherapy for spinal meningiomas: insights from the 2004-2015 National Cancer Database

OBJECTIVERecent studies have reported on the utility of radiosurgery for local control and symptom relief in spinal meningioma. The authors sought to evaluate national utilization trends in radiotherapy (including radiosurgery), investigate possible factors associated with its use in patients with spinal meningioma, and its impact on survival for atypical tumors.METHODSUsing the ICD-O-3 topographical codes C70.1, C72.0, and C72.1 and histological codes 9530-9535 and 9537-9539, the authors queried the National Cancer Database for patients in whom spinal meningioma had been diagnosed between 2004 and 2015. Patients who had undergone radiation in addition to surgery and those who had received radiation as the only treatment were analyzed for factors associated with each treatment.RESULTSFrom among 10,458 patients with spinal meningioma in the database, the authors found a total of 268 patients who had received any type of radiation. The patients were divided into two main groups for the analysis of radiation alone (137 [51.1%]) and radiation plus surgery (131 [48.9%]). An age > 69 years (p < 0.001), male sex (p = 0.03), and tumor size 5 to < 6 cm (p < 0.001) were found to be associated with significantly higher odds of receiving radiation alone, whereas a Charlson-Deyo Comorbidity Index ≥ 2 (p = 0.01) was associated with significantly lower odds of receiving radiation alone. Moreover, a larger tumor size (2 to < 3 cm, p = 0.01; 3 to < 4 cm, p < 0.001; 4 to < 5 cm, p < 0.001; 5 to < 6 cm, p < 0.001; and ≥ 6 cm, p < 0.001; reference = 1 to < 2 cm), as well as borderline (p < 0.001) and malignant (p < 0.001) tumors were found to be associated with increased odds of undergoing radiation in addition to surgery. Receiving adjuvant radiation conferred a significant reduction in overall mortality among patients with borderline or malignant spinal meningiomas (HR 2.12, 95% CI 1.02-4.1, p = 0.02).CONCLUSIONSThe current analysis of cases from a national cancer database revealed a small increase in the use of radiation for the management of spinal meningioma without a significant increase in overall survival. Larger tumor size and borderline or malignant behavior were found to be associated with increased radiation use. Data in the present analysis failed to show an overall survival benefit in utilizing adjuvant radiation for atypical tumors.

Treatment Outcomes of Incidental Intracranial Meningiomas: Results from the IMPACT Cohort

BACKGROUND

Incidental findings such as meningioma are becoming increasingly prevalent. There is no consensus on the optimal management of these patients. The aim of this study was to examine the outcomes of patients diagnosed with an incidental meningioma who were treated with surgery or radiotherapy.

METHODS

Single-center retrospective cohort study of adult patients diagnosed with an incidental intracranial meningioma (2007-2015). Outcomes recorded were postintervention morbidity, histopathologic diagnosis, and treatment response.

RESULTS

Out of 441 patients, 44 underwent treatment. Median age at intervention was 56.1 years (interquartile range [IQR], 49.6-66.5); patients included 35 women and 9 men. The main indication for imaging was headache (25.9%). Median meningioma volume was 4.55 cm³ (IQR, 1.91-8.61), and the commonest location was convexity (47.7%). Six patients underwent surgery at initial diagnosis. Thirty-eight had intervention (34 with surgery and 4 with radiotherapy) after a median active monitoring duration of 24 months (IQR, 11.8-42.0). Indications for treatment were radiologic progression (n = 26), symptom development (n = 6), and patient preference (n = 12). Pathology revealed World Health Organization (WHO) grade 1 meningioma in 36 patients and WHO grade 2 in 4 patients. The risk of postoperative surgical and medical morbidity requiring treatment was 25%. Early and late moderate adverse events limiting activities of daily living occurred in 28.6% of patients treated with radiotherapy. Recurrence rate after surgery was 2.5%. All meningiomas regressed or remained radiologically stable after radiotherapy.

CONCLUSIONS

The morbidity after treatment of incidental intracranial meningioma is not negligible. Considering most operated tumors are WHO grade 1, treatment should be reserved for those manifesting symptoms or demonstrating substantial growth on radiologic surveillance.

Trends in the Management Paradigms of Intracranial Meningioma

Objective  Intracranial meningiomas are the most common primary brain tumor. Treatment paradigms have evolved over time. There are limited number of population-based studies that examine this modern evolution. Here, we describe the trends of management of intracranial meningiomas using a national database. Methods  The data were obtained from the National Cancer Database for the years 2004 to 2015, the collected variables included: patients' age, gender, insurance type, income, comorbidity score, the tumor size and grade, and treatment modality (observation, surgery, radiotherapy, or combination therapy). We performed statistical analyses to detect association between unique variables and outcomes. In addition, we performed mortality analyses for various treatment modalities. Results  A total of 199,096 patients with a diagnosis of intracranial meningioma were included, the majority of patients were white females, mean age of 61 years, and half of the tumors were ≤ 3 cm. Observation was the most commonly used management modality followed by surgical resection, radiotherapy, and combination therapy. For the entire time period, there was an increased use of observation as a primary management method. Predictors of mortality included increased age, larger tumor size, higher tumor grade, treatment at a community hospital, and higher comorbidity scores. Conclusion  Population-based studies of intracranial meningiomas are uncommon; our study is one of the few reports that examine the changes in the modern management paradigms of meningioma in the United States over time. Additionally, we shed light on the factors that affected survival of patients with this condition.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Incidental intracranial meningiomas: a systematic review and meta-analysis of prognostic factors and outcomes

BACKGROUND

Incidental discovery accounts for 30% of newly-diagnosed intracranial meningiomas. There is no consensus on their optimal management. This review aimed to evaluate the outcomes of different management strategies for these tumors.

METHODS

Using established systematic review methods, six databases were scanned up to September 2017. Pooled event proportions were estimated using a random effects model. Meta-regression of prognostic factors was performed using individual patient data.

RESULTS

Twenty studies (2130 patients) were included. Initial management strategies at diagnosis were: surgery (27.3%), stereotactic radiosurgery (22.0%) and active monitoring (50.7%) with a weighted mean follow-up of 49.5 months (SD = 29.3). The definition of meningioma growth and monitoring regimens varied widely impeding relevant meta-analysis. The pooled risk of symptom development in patients actively monitored was 8.1% (95% CI 2.7-16.1). Associated factors were peritumoral edema (OR 8.72 [95% CI 0.35-14.90]) and meningioma diameter ≥ 3 cm (OR 34.90 [95% CI 5.17-160.40]). The pooled proportion of intervention after a duration of active monitoring was 24.8% (95% CI 7.5-48.0). Weighted mean time-to-intervention was 24.8 months (SD = 18.2). The pooled risks of morbidity following surgery and radiosurgery, accounting for cross-over, were 11.8% (95% CI 3.7-23.5) and 32.0% (95% CI 10.6-70.5) respectively. The pooled proportion of operated meningioma being WHO grade I was 94.0% (95% CI 88.2-97.9).

CONCLUSION

The management of incidental meningioma varies widely. Most patients who clinically or radiologically progressed did so within 5 years of diagnosis. Intervention at diagnosis may lead to unnecessary overtreatment. Prospective data is needed to develop a risk calculator to better inform management strategies.

Neurosurgical treatment and outcome patterns of meningioma in Sweden: a nationwide registry-based study

Background

Surgery is the main treatment modality for intracranial meningiomas, but data on short-term surgical outcome are limited. The aim of this Swedish nationwide registry-based study was to benchmark the 30-day complication rate in a cohort of meningioma patients using data from the Swedish brain tumor registry (SBTR). Furthermore, we investigated outcomes for asymptomatic patients.

Methods

Data were collected from the SBTR for all adults with histopathologically verified intracranial meningioma between 2009 and 2015. Patient symptoms, tumor characteristics, and complications within 30 days postoperatively were analyzed.

Results

In total, 2324 patients, with a mean age of 58.7 years (SD 13.5), underwent surgery for intracranial meningioma and 14.1% of the patients were asymptomatic before the intervention. The most common symptom prior to treatment was focal deficit, which occurred in 1450 patients (62.4%). Moreover, within 30 days after surgery, 344 patients (14.8%) developed new neurological deficits and new-onset seizures occurred in 105 patients (4.5%), while 8.3% of asymptomatic patients developed neurological deficit and 3.7% new-onset seizures. Due to complications, reoperations were performed in 120 patients (5.2%). The postoperative 30-day mortality in the whole cohort was 1.5%.

Conclusion

This study benchmarks the 30-day complication rate after meningioma surgery and provides outcome data in the highly relevant group of asymptomatic patients using data from the Swedish brain tumor registry. Since surgical decision-making is a careful consideration of short-term risk versus long-term benefit, this information may be useful for both caregivers and patients.

Racial Differences in Disease Presentation and Management of Intracranial Meningioma

Objective/Hypothesis  The aim of the study was to determine the impact of race on disease presentation and treatment of intracranial meningioma in the United States. Study Design  This study comprised of the analysis of a national population-based tumor registry. Methods  Analysis of the surveillance, epidemiology, and end results (SEER) database was performed, including all patients identified with a diagnosis of intracranial meningioma. Associations between race, disease presentation, treatment strategy, and overall survival were analyzed in a univariate and multivariable model. Results  A total of 65,973 patients with intracranial meningiomas were identified. Of these, 45,251 (68.6%) claimed white, 7,796 (12%) black, 7,154 (11%) Hispanic, 4,902 (7%) Asian, and 870 (1%) patients reported "other-unspecified" or "other-unknown." The median annual incidence of disease was lowest among black (3.43 per 100,000 persons) and highest among white (9.52 per 100,000 persons) populations ( p  < 0.001). Overall, Hispanic patients were diagnosed at the youngest age and white patients were diagnosed at the oldest age (mean of 59 vs. 66 years, respectively; p  < 0.001). Compared with white populations, black, Hispanic, and Asian populations were more likely to present with larger tumors ( p  < 0.001). After controlling for tumor size, age, and treatment center in a multivariable model, Hispanic patients were more likely to undergo surgery than white, black, and Asian populations. Black populations had the poorest disease specific and overall survival rates at 5 years following surgery compared with other groups. Conclusion  Racial differences among patients with intracranial meningioma exist within the United States. Understanding these differences are of vital importance toward identifying potential differences in the biological basis of disease or alternatively inequalities in healthcare delivery or access Further studies are required to determine which factors drive differences in tumor size, age, annual disease incidence, and overall survival between races.

National care among patients with WHO grade I intracranial meningioma

PURPOSE

To analyze the national treatment trends of patients diagnosed with benign intracranial meningioma.

METHODS AND MATERIALS

Data was obtained from the National Cancer Database (NCDB) for patients with WHO grade I meningioma tumors between 2004 and 2014 (190,527 patients), diagnosed by either surgical specimen or diagnostic imaging. Univariable and multivariable analyses (binary logistic models) were performed to generate odds ratios (OR) and investigate factors associated with definitive initial treatment compared to initial observation. Initial treatments considered included surgical resection and/or radiation, including either fractionated external beam radiotherapy (EBRT) or stereotactic radiosurgery (SRS).

RESULTS

The rate of observation increased over time, from 37% in 2004 to 55% in 2014 (p < 0.001). Conjointly, the rate of resection decreased from 50% to 37% from 2004 to 2014 (p < 0.001). The utilization of radiotherapy, including SRS, remained generally stable over time at 6% or less. SRS was more frequently utilized, compared to EBRT, as definitive treatment (4.6% versus 1.7%, respectively, p < 0.001). Compared to Community Cancer programs, patients at Academic/Research programs were more likely to receive definitive initial treatment over observation (OR = 2.909, each p < 0.001).

CONCLUSIONS

There is a national trend favoring initial observation for radiographically diagnosed WHO grade I meningioma. However, patients presenting to academic facilities are more likely to receive definitive initial treatment. Further research into differing approaches among treatment facilities for this common tumor may help clarify this trend.