The importance of considering competing risks in recurrence analysis of intracranial meningioma

BACKGROUND

The risk of recurrence is overestimated by the Kaplan-Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan-Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated.

METHODS

We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan-Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions.

RESULTS

Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan-Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions).

CONCLUSION

The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions.

ALA-RDT in GBM: protocol of the phase I/II dose escalation trial of radiodynamic therapy with 5-Aminolevulinic acid in patients with recurrent glioblastoma

BACKGROUND

Despite improvements in surgical as well as adjuvant therapies over the last decades, the prognosis for patients with glioblastoma remains poor. Five-Aminolevulinic acid (5-ALA) induced porphyrins are already used for fluorescence-guided resection and as photosensitizer for photodynamic therapy. New findings reveal their potential use as sensitizing agents in combination with ionizing radiation.

METHODS

We initiated a phase I/II dose escalation study, treating patients with recurrence of glioblastoma with oral 5-ALA concurrent to radiotherapy (RT). This prospective single-center study based in the University Hospital Münster aims to recruit 30 patients over 18 years of age with histologically verified recurrence of supratentorial glioblastoma in good performance status (KPS ≥ 60). Following a 3 + 3 dose-escalation design, patients having undergone re-resection will receive a 36 Gy RT including radiodynamic therapy fractions (RDT). RDT constitutes of oral administration of 5-ALA before the irradiation session. Two cohorts will additionally receive two fractions of neoadjuvant treatment three and two days before surgery. To determine the maximum tolerated dose of repeated 5-ALA-administration, the number of RDT-fractions will increase, starting with one to a maximum of eight fractions, while closely monitoring for safety and toxicity. Follow-up will be performed at two and five months after treatment. Primary endpoint will be the maximum tolerated dose (MTD) of repeated ALA-administration, secondary endpoints are event-free-, progression-free-, and overall-survival. Additionally, 5-ALA metabolites and radiobiological markers will be analysed throughout the course of therapy and tissue effects after neoadjuvant treatment will be determined in resected tissue. This protocol is in accordance with the SPIRIT guidelines for clinical trial protocols.

DISCUSSION

This is the protocol of the ALA-RDT in GBM-study, the first-in-man evaluation of repeated administration of 5-ALA as a radiosensitizer for treatment of recurrent glioblastoma.

TRIAL REGISTRATION

This study was approved by the local ethics committee of the Medical Association of Westphalia-Lippe and the University of Münster on 12.10.2022, the German federal institute for Drugs and medical devices on 13.10.2022 and the federal office for radiation protection on 29.08.2022. This trial was registered on the public European EudraCT database (EudraCT-No.: 2021-004631-92) and is registered under www.cliniclatrials.gov (Identifier: NCT05590689).

Radiomics-Based Prediction of TERT Promotor Mutations in Intracranial High-Grade Meningiomas

PURPOSE

In meningiomas, TERT promotor mutations are rare but qualify the diagnosis of anaplasia, directly impacting adjuvant therapy. Effective screening for patients at risk for promotor mutations could enable more targeted molecular analyses and improve diagnosis and treatment.

METHODS

Semiautomatic segmentation of intracranial grade 2/3 meningiomas was performed on preoperative magnetic resonance imaging. Discriminatory power to predict TERT promoter mutations was analyzed using a random forest algorithm with an increasing number of radiomic features. Two final models with five and eight features with both fixed and differing radiomics features were developed and adjusted to eliminate random effects and to avoid overfitting.

RESULTS

A total of 117 image sets including training (N = 94) and test data (N = 23) were analyzed. To eliminate random effects and demonstrate the robustness of our approach, data partitioning and subsequent model development and testing were repeated a total of 100 times (each time with repartitioned training and independent test data). The established five- and eight-feature models with both fixed and different radiomics features enabled the prediction of TERT with similar but excellent performance. The five-feature (different/fixed) model predicted TERT promotor mutation status with a mean AUC of 91.8%/94.3%, mean accuracy of 85.5%/88.9%, mean sensitivity of 88.6%/91.4%, mean specificity of 83.2%/87.0%, and a mean Cohen's Kappa of 71.0%/77.7%. The eight-feature (different/fixed) model predicted TERT promotor mutation status with a mean AUC of 92.7%/94.6%, mean accuracy of 87.3%/88.9%, mean sensitivity of 89.6%/90.6%, mean specificity of 85.5%/87.5%, and a mean Cohen's Kappa of 74.4%/77.6%. Of note, the addition of further features of up to N = 8 only slightly increased the performance.

CONCLUSIONS

Radiomics-based machine learning enables prediction of TERT promotor mutation status in meningiomas with excellent discriminatory performance. Future analyses in larger cohorts should include grade 1 lesions as well as additional molecular alterations.

Pronounced mediastinal emphysema after restorative treatment of the lower left molar-a case report and a systematic review of the literature

This case report presents an iatrogenic induced mediastinal emphysema after restorative treatment of the lower left second molar, aimed to highlight the potential life-threatening consequences, and providing diagnostics and treatment concepts of complicated dental induced emphysema based on literature review. A 74-year-old female patient was admitted to the emergency department due to a fall on her shoulder. Additional finding was a significant swelling of the face and neck. In the computer tomography of the head, neck, and thorax, a humerus fracture and pronounced soft tissue emphysema from the infraorbital region to the mediastinum was detected. The patient reported that she had been treated by her dentist 4 days earlier. The treatment had to be discontinued after beginning of a pronounced swelling. Other reasons for the emphysema could be excluded out on an interdisciplinary teamwork. The patient was monitored as an inpatient for 5 days and received intravenous antibiotic therapy. This case report shows the rare complication of pronounced mediastinal emphysema after root canal treatment. Emphysema should always be a differential diagnosis of soft tissue swelling and, in case of doubt, a general medical presentation should be made.

Which risk factors significantly influence the outcome of traumatic brain injured patients with alcohol use disorder?

PURPOSE

Every year, approximately 10 million people worldwide suffer a traumatic brain injury that leads to hospitalization or mortality. Chronic and acute alcohol intoxication increase the risk of developing traumatic brain injury. Alcohol use disorder (AUD) as a predictor of outcome in neurosurgical patients and the definition of risk factors have been sparsely addressed so far. This study aims to improve the understanding of the effects of alcohol use disorder in the context of neurosurgical therapy.

METHODS

This study included patients admitted to Münster University Hospital with a traumatic brain injury and alcohol use disorder from January 1, 2010, to December 31, 2018. Univariate and multivariate analyses were performed to identify risk factors for a poorer outcome, assessed by the Glasgow Outcome Score.

RESULTS

Of the 197 patients included, 156 (79%) were male, and 41 (21%) were female, with a median age of 49 years (IQR 38-58 years). In multivariate analyses, age (p < 0.001), the occurrence of a new neurologic deficit (p < 0.001), the development of hydrocephalus (p = 0.005), and CT-graphic midline shift due to intracerebral hemorrhage (p = 0.008) emerged as significant predictors of a worse outcome (GOS 1-3). In addition, the level of blood alcohol concentration correlated significantly with the occurrence of seizures (p = 0.009).

CONCLUSIONS

Early identification of risk factors in patients with alcohol use disorder and traumatic brain injury is crucial to improve the outcome. In this regard, the occurrence of hydrocephalus or seizures during the inpatient stay should be considered as cause of neurological deterioration in this patient group.

Prognosis and histology of sporadic synchronous and metachronous meningiomas and comparative analyses with singular lesions

Synchronous or metachronous growth of multiple tumors (≥ 2) is found in up to 20% of meningioma patients. However, biological as well as histological features and prognosis are largely unexplored. Clinical and histological characteristics were retrospectively investigated in 95 patients harboring 226 multiple meningiomas (MMs) and compared with 135 cases of singular meningiomas (SM) using uni- and multivariate analyses. In MM, tumors occurred synchronously and metachronously in 62% and 38%, respectively. WHO grade was intra-individually constant in all but two MMs, and histological subtype varied in 13% of grade 1 tumors. MM occurred more commonly in convexity/parasagittal locations, while SM were more frequent at the skull base (p < .001). In univariate analyses, gross total resection (p = .014) and high-grade histology in MM were associated with a prolonged time to progression (p < .001). Most clinical characteristics and rates of high-grade histology were similar in both groups (p ≥ .05, each). Multivariate analyses showed synchronous/metachronous meningioma growth (HR 4.50, 95% CI 2.26-8.96; p < .001) as an independent predictor for progression. Compared to SM, risk of progression was similar in cases with two (HR 1.56, 95% CI .76-3.19; p = .224), but exponentially raised in patients with 3-4 (HR 3.25, 1.22-1.62; p = .018) and ≥ 5 tumors (HR 13.80, 4.06-46.96; p < .001). Clinical and histological characteristics and risk factors for progression do not relevantly differ between SM and MM. Although largely constant, histology and WHO grade occasionally intra-individually vary in MM. A distinctly higher risk of disease progression in MM as compared to SM might reflect different underlying molecular alterations.

Vascular anomalies in patients with growth hormone-secreting pituitary adenomas: illustrative case report and systematic review of the literature

PURPOSE

Endonasal resection is the first-line treatment for patients harboring growth hormone (GH)-secreting pituitary adenomas. The complexity of the parasellar neurovascular structures makes pre-operative diagnostic imaging essential to understanding the anatomy of this region. We aimed to describe vascular anomalies in acromegalic patients and emphasize their relevance for surgery and preoperative planning.

METHODS

A systematic review following the PRISMA statement was performed in July 2021.

RESULTS

Thirty-three studies were evaluated. Elevated GH and insulin-like growth factor-1 (IGF-1) levels are linked to the occurrence of cardiovascular risk factors. This is attributed to endothelial dysfunction, mainly caused by changes in flow-mediated dilatation (FMD), which is probably the main cause of vascular anomalies in acromegaly. The occurrence of protrusions of the internal carotid artery (ICA) (35-53%), a narrow intercarotid distance, and an asymmetrical course was described. In 13-18% of acromegalic patients, the presence of an intracerebral aneurysm could be reported (incidence in the general population:0.8-1.3%). The selected studies were however performed with a small patient sample (range:1-257). We present a case report of a 57y/o male patient with anomalies of the ICA ("kissing carotid arteries") harboring a GH-secreting adenoma, which was resected via an endoscopic endonasal approach.

CONCLUSIONS

There is an association between acromegaly and endothelial dysfunction, which increases cardiovascular risk factors and vascular anomalies. Preoperative vascular imaging, e.g., CT angiography, should be implemented as a standard to identify patients at risk and estimate surgical morbidity. However, no evidence-based recommendations exist so far, so future studies are necessary.

Changes in hormones of the thyroid axis after tracheostomy and their influence on regeneration in patients with head and neck cancer: A prospective study

This prospective study aimed to compare and evaluate changes in hormones of the thyroid axis affected by tracheostomy due to surgical treatment in patients with oral cancer. The patients were evaluated with regard to serum levels of the thyroid axis - free T3/triiodothyronine (fT3) and free T4/thyroxine (fT4), as well as thyroid-stimulating hormone (TSH) - at fixed perioperative time points: during the tumor staging about 1 week before operation, immediately before and within 6 h after operation, 2 days after operation, and about 10 days after operation. Additionally, data on the patients' characteristics (age, gender), relevant secondary diagnoses, duration of ventilation in the intensive care unit, and perioperative complications were obtained and analyzed. In total, 51 patients with an average age of 68.29 years (±11.82) were included. Analyses of thyroid hormones directly before and after tracheostomy showed a significant postoperative decrease in circulating TSH (p = 0.005) and fT3 (p < 0.001), whilst a significant increase in fT4 values (p < 0.001) was found. Nine patients showed perioperative complications, such as infection, emphysema, or requiring a revision operation. Eleven patients were diagnosed with a cardiac problem or suffered from agitation after operation. Within the limitations of the study it seems that hormonal changes following tracheostomy in critically ill patients should be monitored and thyroid hormone adjustment should be taken into account because the latter might lead to lower mortality and morbidity during hospitalization in these patients. CLINICAL TRIAL REGISTRATION NUMBER: DRKS00023942.

CTNI-18. FIRST MULTICENTRIC REAL-LIFE EXPERIENCE WITH THE COMBINATION OF CCNU AND TEMOZOLOMIDE IN NEWLY DIAGNOSED MGMT PROMOTER METHYLATED IDH WILDTYPE GLIOBLASTOMA

BACKGROUND

The randomized phase 3 CeTeG/NOA-09 trial assessed whether CCNU plus temozolomide was superior to temozolomide alone in newly diagnosed MGMT promoter methylated glioblastoma patients. Survival was significantly improved from 31.4 months (temozolomide) to 48.1 months (CCNU plus temozolomide). In view of this encouraging data, we assessed safety and efficacy of this regimen under real-life conditions.

METHODS

We retrospectively collected clinical and radiographic data from adult newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma patients from five neuro-oncology centers in Germany. For inclusion in our analysis, treatment with CCNU and temozolomide had to be performed for at least six weeks (one course).

RESULTS

Seventy patients were included. Median progression-free survival was 14.4 months and median overall survival 33.8 months. Patients with TTFields treatment for at least eight weeks and CCNU plus temozolomide (n = 22, 31%) had a prolonged progression-free survival compared to those with TTFields treatment for less than eight weeks (n = 48, 69%) (21.5 versus 11.2 months; p = 0.0105). In a multivariable Cox regression analysis, TTFields treatment for eight weeks or longer together with CCNU plus temozolomide and a Karnofsky performance score ≥ 90% were independent prognostic factors for progression-free and overall survival. Pseudoprogression occurred in n = 16 (33%) of investigated n = 49 (70%) patients. In n = 31 (44%) patients high-grade hematotoxicity was observed.

CONCLUSIONS

The results from this multicentric trial indicate - under real-life conditions - toxicity and survival estimates comparable to the CeTeG/NOA-09 trial. TTFields therapy for at least eight weeks in combination with this regimen was independently associated with prolonged survival.

Postoperative surveillance in cranial and spinal tumor neurosurgery: when is this warranted?

OBJECTIVE

The outbreak of COVID-19 and the sudden increase in the number of patients requiring mechanical ventilation significantly affected the management of neurooncological patients. Hospitals were forced to reallocate already scarce human resources to maximize intensive care unit (ICU) capacities, resulting in a significant postponement of elective procedures for patients with brain and spinal tumors, who traditionally require elective postoperative surveillance on ICU or intermediate care wards. This study aimed to characterize those patients in whom postoperative monitoring is required by analyzing early postoperative complications and associated risk factors.

METHODS

All patients included in the analysis experienced benign or malignant cerebral or intradural tumors and underwent surgery between September 2017 and May 2019 at University Hospital Münster, Germany. Patient data were generated from a semiautomatic, prospectively designed database. The occurrence of adverse events within 24 hours and 30 days postoperatively-including unplanned reoperation, postoperative hemorrhage, CSF leakage, and pulmonary embolism-was chosen as the primary outcome measure. Furthermore, reasons and risk factors that led to a prolonged stay on the ICU were investigated. By performing multivariable logistic regression modeling, a risk score for early postoperative adverse events was calculated by assigning points based on beta coefficients.

RESULTS

Eight hundred eleven patients were included in the study. Eleven patients (1.4%) had an early adverse event within 24 hours, which was either an unplanned reoperation (0.9%, n = 7) or a pulmonary embolism (0.5%, n = 4) within 24 hours. To predict the incidence of early postoperative complications, a score was developed including the number of secondary diagnoses, BMI, and incision closure time, termed the SOS score. According to this score, 0.3% of the patients were at low risk, 2.5% at intermediate risk, and 12% at high risk (p < 0.001).

CONCLUSIONS

Postoperative surveillance in cranial and spinal tumor neurosurgery might only be required in a distinct patient collective. In this study, the authors present a new score allowing efficient prediction of the likelihood of early adverse events in patients undergoing neurooncological procedures, thus helping to stratify the necessity for ICU or intermediate care unit beds. Nevertheless, validation of the score in a multicenter prospective setting is needed.

P18.01.A The applicability of established clinical and histopathological risk factors for tumor recurrence during long-term perioperative care in meningioma patients

Background

Risk factors for the prediction of late-onset tumor recurrence in meningioma patients are sparse but needed to estimate duration and control intervals during long-term follow-up in meningioma patients. In this study, we therefore analyzed the value of established risk factors for postoperative meningioma recurrence for the prediction of long-term prognosis in a large, single-center series.

Material and methods

Correlations of established clinical (age, sex, tumor location, extent of resection), radiological (postoperative tumor volume) and histopathological variables (WHO grade, brain invasion) with tumor relapse were analyzed separately after 3, 5, and 10 years following microsurgery for primary diagnosed intracranial meningioma between 1991 and 2021 in uni- and multivariate analyses. The prognostic value was compared to findings in the entire cohort.

Results

Within a median follow-up of 29 months (range: 0-307 months), recurrence was observed in 141 patients (12%) after a median PFS of 36 months. PFS among the entire cohort (n=1218) at 3, 5, 10 and 15 years postoperatively were 90%, 84%, 74% and 70%, respectively. Among all patients included, skull base location (HR: 1.51, 95%CI 1.05-2.16; p=.026), Simpson ≥IV resections (HR: 2.41, 95%CI 1.52-3.84; p&lt;.001), high-grade histology (HR: 3.70, 95%CI 2.50-5.47; p&lt;.001) and male gender (HR: 1.46, 95%CI 1.01-2.11; p=.042) were independent risk factors for recurrence. Skull base location (HR: 1.92, 95%CI 1.17-3.17; p=.010 and HR: 2.02, 95%CI 1.04-3.95; p=.038) and high-grade histology (HR: 1.87, 95%CI 1.04-3.38; p=.038 and HR: 2.29, 95%CI 1.07-4.01; p=.034) but not subtotal resection (HR: 1.53, 95%CI .68-3.45; p=.303 and HR: 1.75, 95%CI .52-5.96; p=.369) remained independently correlated with recurrence after an event-free PFS of at least three (n=485) and five years (n=346), respectively. Similarly, postoperative tumor volume was related with recurrence in the entire cohort (p&lt;.001) but not beyond a follow-up of ≥ three years (p&gt;.05). In 147 patients with a follow-up of ≥ ten years, ten recurrences occurred, and no correlation was found with any of the analyzed variables.

Conclusion

Skull base tumor location and high-grade histology but not the extent of resection should be considered when planning follow-up duration and intervals following ≥5 years after meningioma surgery. Tumor relapses following more than ten years after surgery are very rare, and corresponding predictors are lacking.

First multicentric real-life experience with the combination of CCNU and temozolomide in newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma

Background

The randomized phase 3 CeTeG/NOA-09 trial assessed whether CCNU plus temozolomide was superior to temozolomide alone in newly diagnosed MGMT promoter methylated glioblastoma patients. Survival was significantly improved from 31.4 months (temozolomide) to 48.1 months (CCNU plus temozolomide). In view of this encouraging data, we assessed safety and efficacy of this regimen under real-life conditions.

Methods

We retrospectively collected clinical and radiographic data from adult newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma patients from five neuro-oncology centers in Germany. For inclusion in our analysis, treatment with CCNU and temozolomide had to be performed for at least six weeks (one course).

Results

Seventy patients were included. Median progression-free survival was 14.4 months and median overall survival 33.8 months. Patients with TTFields treatment for at least 8 weeks and CCNU plus temozolomide (n = 22, 31%) had a prolonged progression-free survival compared to those with TTFields treatment for less than eight weeks (n = 48, 69%) (21.5 versus 11.2 months; P = .0105). In a multivariable Cox regression analysis, TTFields treatment for eight weeks or longer together with CCNU plus temozolomide and a Karnofsky performance score ≥ 90% were independent prognostic factors for progression-free and overall survival. Pseudoprogression occurred in n = 16 (33%) of investigated n = 49 (70%) patients. In n = 31 (44%) patients high-grade hematotoxicity was observed.

Conclusions

The results from this multicentric trial indicate that—under real-life conditions—toxicity and survival estimates are comparable to the CeTeG/NOA-09 trial. TTFields therapy for at least eight weeks in combination with this regimen was independently associated with prolonged survival.

Expression of decitabine-targeted oncogenes in meningiomas in vivo

Treatment of meningiomas refractory to surgery and irradiation is challenging and effective chemotherapies are still lacking. Recently, in vitro analyses revealed decitabine (DCT, 5-aza-2’–deoxycytidine) to be effective in high-grade meningiomas and, moreover, to induce hypomethylation of distinct oncogenes only sparsely described in meningiomas in vivo yet.

Expression of the corresponding onco- and tumor suppressor genes TRIM58, FAM84B, ELOVL2, MAL2, LMO3, and DIO3 were analyzed and scored by immunohistochemical staining and RT-PCR in samples of 111 meningioma patients. Correlations with clinical and histological variables and prognosis were analyzed in uni- and multivariate analyses.

All analyzed oncogenes were highly expressed in meningiomas. Expression scores of TRIM58 tended to be higher in benign than in high-grade tumors 20 vs 16 (p = .002) and all 9 samples lacking TRIM58 expression displayed WHO grade II/III histology. In contrast, median expression scores for both FAM84B (6 vs 4, p ≤ .001) and ELOVL2 (9 vs 6, p < .001) were increased in high-grade as compared to benign meningiomas. DIO3 expression was distinctly higher in all analyzed samples as compared to the reference decitabine-resistant Ben-Men 1 cell line. Increased ELOVL2 expression (score ≥ 8) correlated with tumor relapse in both uni- (HR: 2.42, 95%CI 1.18–4.94; p = .015) and multivariate (HR: 2.09, 95%CI 1.01–4.44; p = .046) analyses.

All oncogenes involved in DCT efficacy in vitro are also widely expressed in vivo, and expression is partially associated with histology and prognosis. These results strongly encourage further analyses of DCT efficiency in meningiomas in vitro and in situ.

The applicability of established clinical and histopathological risk factors for tumor recurrence during long-term postoperative care in meningioma patients

Risk factors to predict late-onset tumor recurrence in meningioma patients are urgently needed to schedule control intervals during long-term follow-up. We therefore analyzed the value of established risk factors for postoperative meningioma recurrence for the prediction of long-term prognosis. Correlations of clinical and histopathological variables with tumor relapse after 3, 5, and 10 years following microsurgery were analyzed in uni- and multivariate analyses, and compared to findings in the entire cohort. In the entire cohort (N = 1218), skull base location (HR: 1.51, 95%CI 1.05–2.16; p = .026), Simpson ≥ IV resections (HR: 2.41, 95%CI 1.52–3.84; p < .001), high-grade histology (HR: 3.70, 95%CI 2.50–5.47; p < .001), and male gender (HR: 1.46, 95%CI 1.01–2.11; p = .042) were independent risk factors for recurrence. Skull base location (HR: 1.92, 95%CI 1.17–3.17; p = .010 and HR: 2.02, 95%CI 1.04–3.95; p = .038) and high-grade histology (HR: 1.87, 95%CI 1.04–3.38; p = .038 and HR: 2.29, 95%CI 1.07–4.01; p = .034) but not subtotal resection (HR: 1.53, 95%CI .68–3.45; p = .303 and HR: 1.75, 95%CI .52–5.96; p = .369) remained correlated with recurrence after a recurrence-free follow-up of ≥ 3 and ≥ 5 years, respectively. Postoperative tumor volume was related with recurrence in general (p < .001) but not beyond a follow-up of ≥ 3 years (p > .05). In 147 patients with a follow-up of ≥ 10 years, ten recurrences occurred and were not correlated with any of the analyzed variables. Skull base tumor location and high-grade histology but not the extent of resection should be considered when scheduling the long-term follow-up after meningioma surgery. Recurrences ≥ 10 years after surgery are rare, and predictors are lacking.

Risk of tumor recurrence in intracranial meningiomas: comparative analyses of the predictive value of the postoperative tumor volume and the Simpson classification

OBJECTIVE

In meningiomas, the Simpson grading system is applied to estimate the risk of postoperative recurrence, but might suffer from bias and limited overview of the resection cavity. In contrast, the value of the postoperative tumor volume as an objective predictor of recurrence is largely unexplored. The objective of this study was to compare the predictive value of residual tumor volume with the intraoperatively assessed extent of resection (EOR).

METHODS

The Simpson grade was determined in 939 patients after surgery for initially diagnosed intracranial meningioma. Tumor volume was measured on initial postoperative MRI within 6 months after surgery. Correlation between both variables and recurrence was compared using a tree-structured Cox regression model.

RESULTS

Recurrence correlated with Simpson grading (p = 0.003). In 423 patients (45%) with available imaging, residual tumor volume covered a broad range (0-78.5 cm3). MRI revealed tumor remnants in 8% after gross-total resection (Simpson grade I-III, range 0.12-33.5 cm3) with a Cohen's kappa coefficient of 0.7153. Postoperative tumor volume was correlated with recurrence in univariate analysis (HR 1.05 per cm3, 95% CI 1.02-1.08 per cm3, p < 0.001). A tree-structured Cox regression model revealed any postoperative tumor volume > 0 cm3 as a critical cutoff value for the prediction of relapse. Multivariate analysis confirmed the postoperative tumor volume (HR 1.05, p < 0.001) but not the Simpson grading (p = 0.398) as a predictor for recurrence.

CONCLUSIONS

EOR according to Simpson grading was overrated in 8% of tumors compared to postoperative imaging. Because the predictive value of postoperative imaging is superior to the Simpson grade, any residual tumor should be carefully considered during postoperative care of meningioma patients.

Prediction of High-Grade Histology and Recurrence in Meningiomas Using Routine Preoperative Magnetic Resonance Imaging: A Systematic Review

OBJECTIVE

Estimating the risk of recurrence after surgery remains crucial during care of patients with meningioma. Numerous studies identified correlations of characteristics on routine preoperative magnetic resonance imaging (MRI) with postoperative recurrence or high-grade histology but showed partially inconclusive results.

METHODS

A systematic review of the literature was performed about findings on preoperative MRI and their correlation with high-grade histology and recurrence. Quality of the included studies was analyzed using standardized Quality Assessment of Diagnostic Accuracy Studies criteria.

RESULTS

Among the 35 studies included, quality of the series according to the Quality Assessment of Diagnostic Accuracy Studies criteria differed widely. Remarkably, MRI variables found to be associated with high-grade histology were commonly not consistently associated with prognosis and vice versa. Correlations of the tumor size, the peritumoral edema size, and contrast-enhancement of the tumor capsule with high-grade histology were controversial. In most studies, non-skull base tumor location, cyst formation, heterogenous contrast-enhancement, an irregular tumor shape, and disruption of the tumor/brain border but not intensity of the lesion on T2-weighted images, calcifications, or bone involvement were associated with grade II/III histology. Although tumor and edema size were usually found to correlate with recurrence, heterogenous contrast enhancement, cyst formation, intensity of the tumor on T2-weighted MRI, and enhancement of the tumor capsule were mostly not related with progression.

CONCLUSIONS

Several mostly consistent but partially inconsistent variables associated with high-grade histology or prognosis were identified. Although standardized studies are needed to provide further clarification, consideration of these findings can help to improve estimation of prognosis and can therefore improve postoperative care in patients with meningioma.

The evolution of cranial meningioma surgery-a single-center 25-year experience

BACKGROUND

There have been major developments in diagnostic and surgical and non-surgical techniques used in the management of meningiomas over last three decades. We set out to describe these changes in a systematic manner.

METHOD

Clinical and radiological data, surgical procedures, complications, and outcome of 817 patients who underwent surgery for primarily diagnosed meningioma between 1991 and 2015 were investigated.

RESULTS

Median age at diagnosis increased significantly from 56 to 59 years (p = .042), while tumor location and preoperative Karnofsky performance status did not change during the observation period. Availability of preoperative MRI increased, and rates of angiography and tumor embolization decreased (p < .001, each). Median duration of total, pre-, and postoperative stay was 13, 2, and 9 days, respectively, and decreased between 1991 and 2015 (p < .001, each). Median incision-suture time varied annually (p < .001) but without becoming clearly longer or shorter during the entire observation period. The use of intraoperative neuronavigation and neuromonitoring increased, while the rates of Simpson grade I and III surgeries decreased (p < .001). Rates of postoperative hemorrhage (p = .997), hydrocephalus (p = .632), and wound infection (p = .126) did not change, while the frequency of early postoperative neurological deficits decreased from 21% between 1991 and 1995 to 13% between 2011 and 2015 (p = .003). During the same time, the rate of surgeries for postoperative cerebrospinal fluid leakage slightly increased from 2 to 3% (p = .049). Within a median follow-up of 62 months, progression was observed in 114 individuals (14%). Progression-free interval did not significantly change during observation period (p > .05). Multivariate analyses confirmed the lack of correlation between year of surgery and tumor relapse (HR: 1.1, p > .05).

CONCLUSIONS

Preoperative diagnosis and surgery of meningiomas have been substantially evolved. Although early neurological outcome has improved, long-term prognosis remains unchanged.

Brain invasion and the risk of seizures in patients with meningioma

OBJECTIVE

Identification of risk factors for perioperative epilepsy remains crucial in the care of patients with meningioma. Moreover, associations of brain invasion with clinical and radiological variables have been largely unexplored. The authors hypothesized that invasion of the cortex and subsequent increased edema facilitate seizures, and they compared radiological data and perioperative seizures in patients with brain-invasive or noninvasive meningioma.

METHODS

Correlations of brain invasion with tumor and edema volumes and preoperative and postoperative seizures were analyzed in univariate and multivariate analyses.

RESULTS

Totals of 108 (61%) females and 68 (39%) males with a median age of 60 years and harboring totals of 92 (52%) grade I, 79 (45%) grade II, and 5 (3%) grade III tumors were included. Brain invasion was found in 38 (22%) patients and was absent in 138 (78%) patients. The tumors were located at the convexity in 72 (41%) patients, at the falx cerebri in 26 (15%), at the skull base in 69 (39%), in the posterior fossa in 7 (4%), and in the ventricle in 2 (1%); the median tumor and edema volumes were 13.73 cm3 (range 0.81-162.22 cm3) and 1.38 cm3 (range 0.00-355.80 cm3), respectively. As expected, edema volume increased with rising tumor volume (p < 0.001). Brain invasion was independent of tumor volume (p = 0.176) but strongly correlated with edema volume (p < 0.001). The mean edema volume in noninvasive tumors was 33.0 cm3, but in invasive tumors, it was 130.7 cm3 (p = 0.008). The frequency of preoperative seizures was independent of the patients' age, sex, and tumor location; however, the frequency was 32% (n = 12) in patients with invasive meningioma and 15% (n = 21) in those with noninvasive meningioma (p = 0.033). In contrast, the probability of detecting brain invasion microscopically was increased more than 2-fold in patients with a history of preoperative seizures (OR 2.57, 95% CI 1.13-5.88; p = 0.025). In univariate analyses, the rate of preoperative seizures correlated slightly with tumor volume (p = 0.049) but strongly with edema volume (p = 0.014), whereas seizure semiology was found to be independent of brain invasion (p = 0.211). In multivariate analyses adjusted for age, sex, tumor location, tumor and edema volumes, and WHO grade, rising tumor volume (OR 1.02, 95% CI 1.00-1.03; p = 0.042) and especially brain invasion (OR 5.26, 95% CI 1.52-18.15; p = 0.009) were identified as independent predictors of preoperative seizures. Nine (5%) patients developed new seizures within a median follow-up time of 15 months after surgery. Development of postoperative epilepsy was independent of all clinical variables, including Simpson grade (p = 0.133), tumor location (p = 0.936), brain invasion (p = 0.408), and preoperative edema volume (p = 0.081), but was correlated with increasing preoperative tumor volume (p = 0.004). Postoperative seizure-free rates were similar among patients with invasive and those with noninvasive meningioma (p = 0.372).

CONCLUSIONS

Brain invasion was identified as a new and strong predictor for preoperative, but not postoperative, seizures. Although also associated with increased peritumoral edema, seizures in patients with invasive meningioma might be facilitated substantially by cortical invasion itself. Consideration of seizures in consultations between the neurosurgeon and neuropathologist can improve the microscopic detection of brain invasion.

The Simpson grading in meningioma surgery: does the tumor location influence the prognostic value?

In meningiomas, location-specific differences of the prognostic value of the Simpson classification are sparsely investigated but can influence strategy of surgery. We therefore compared the prognostic value of the Simpson classification in different tumor locations. Progression was compared with Simpson grade in 826 meningioma patients (median age 58 years, female:male ratio 2.4) in location-specific uni- and multivariate analyses. Simpson grade strongly correlated with tumor location (p < .001). Within a median follow-up of 50 months, recurrence was observed in 107 of 803 patients (13%). In general, increasing Simpson grade (p = .002) and subtotal resection (STR, ≥grade III) were correlated with tumor recurrence [hazard ratio (HR): 1.87; p = .004]. In 268 convexity meningiomas, frequency of tumor recurrence correlated with Simpson grade (p = .034). Risk of recurrence was similar after grade I and II resections, tended to increase after grade III (HR: 2.35; p = .087) but was higher after grade IV resections (HR: 7.35; p = .003). Risk of recurrence was higher after STR (HR: 4.21; p = .001) than after gross total resection (GTR, ≤grade II). Contrarily, increasing Simpson grade and STR were not correlated with progression in 102 falx, 38 posterior fossa and nine intraventricular meningiomas. In 325 skull base lesions, risk of recurrence was similar after GTR and STR (p = .198) and was only increased after grade IV resections (HR: 3.26; p = .017). Simpson grading and extent of resection were not equally prognostic in all locations. Lower impact of extent of resection should be considered during surgery for skull base, posterior fossa and falx meningiomas.

Surgery for meningioma in the elderly and long-term survival: comparison with an age- and sex-matched general population and with younger patients

OBJECTIVE

The purpose of this study was to compare long-term prognosis after meningioma surgery in elderly and younger patients as well as to compare survival of elderly patients with surgically treated meningioma to survival rates for the general population.

METHODS

Five hundred meningioma patients (median follow-up 90 months) who underwent surgery between 1994 and 2009 were subdivided into “elderly” (age ≥ 65 years, n = 162) and “younger” (age < 65 years, n = 338) groups for uni- and multivariate analyses. Mortality was compared with rates for the age- and sex-matched general population.

RESULTS

The median age at diagnosis was 71 in the elderly group and 51 years in the younger group. Sex, intracranial tumor location, grade of resection, radiotherapy, and histopathological subtypes were similar in the 2 groups. High-grade (WHO Grades II and III) and spinal tumors were more common in older patients than in younger patients (15% vs 8%, p = 0.017, and 12% vs 4%, p = 0.001, respectively). The progression-free interval (PFI) was similar in the 2 groups, whereas mortality at 3 months after surgery was higher and median overall survival (OS) was shorter in older patients (7%, 191 months) than in younger patients (1%, median not reached; HR 4.9, 95% CI 2.75–8.74; p < 0.001). Otherwise, the median OS in elderly patients did not differ from the anticipated general life expectancy (HR 1.03, 95% CI 0.70–1.50; p = 0.886). Within the older patient group, PFI was lower in patients with high-grade meningiomas (HR 24.74, 95% CI 4.23–144.66; p < 0.001) and after subtotal resection (HR 10.57, 95% CI 2.23–50.05; p = 0.003). Although extent of resection was independent of perioperative mortality, the median OS was longer after gross-total resection than after subtotal resection (HR 2.7, 95% CI 1.09–6.69; p = 0.032).

CONCLUSIONS

Elderly patients with surgically treated meningioma do not suffer from impaired survival compared with the age-matched general population, and their PFI is similar to that of younger meningioma patients. These data help mitigate fears concerning surgical treatment of elderly patients in an aging society.

Brain Invasion in Meningiomas: Incidence and Correlations with Clinical Variables and Prognosis

OBJECTIVE

In meningioma, correlation of brain invasion with prognosis and clinical variables remains controversial.

METHODS

Correlation of brain invasion with clinical and histopathologic variables was investigated in 467 patients with primary intracranial meningioma.

RESULTS

Diffuse (n = 3; 10%), clusterlike (n = 11; 34%) or fingerlike (n = 18; 56%) invasion was detected in 32 patients (7%). Brain invasion was more common in males than in females (13% vs. 5%; odds ratio, 2.75; 95% confidence interval, 1.29-5.89; P = 0.009) and pattern of invasion differed between genders (P = 0.037). Brain invasion was absent in 401 benign meningiomas and present in 48% of 60 atypical (n = 29) and 50% of 6 anaplastic (n = 3) meningiomas (P < 0.001) but was independent of tumor location and extent of resection. Progression occurred in 11% and was more frequent (31% vs. 15%; P = 0.036) in invasive than in noninvasive tumors, but only after gross total resection and in univariate analyses, and independent of invasion pattern. In atypical meningiomas, frequency of adjuvant irradiation was similar comparing invasive and noninvasive tumors and grading solely based on brain invasion (n = 20; 33%), other World Health Organization (WHO) criteria (n = 31; 52%) or a combination of both (n = 9; 15%). Risk of recurrence was lower (hazard ratio, 0.258, 95% confidence interval, 0.09-0.734; P = 0.011) when grading exclusively based on brain invasion than when further WHO criteria were in addition present and the progression-free interval among the first was similar to benign tumors.

CONCLUSIONS

Brain invasion and its patterns are correlated to gender. In contrast to the current WHO classification, invasion was associated with recurrence only after gross total resection and not independent of further histopathologic criteria of atypia.