Recurrence rate of sphenoid wing meningiomas and role of peritumoural brain edema: a single center retrospective study

Objective: To evaluate the recurrence rate of the operatively treated sphenoid wing meningiomas (SWMs) in relation to other factors and role of PTBE in recurrence as a prognostic factors in a series of 67 patients. Materials and methods: The magnetic resonance imaging (MRI), and pathology data for 67 patients with SWM, who underwent surgery at Uzhhorod Regional Neurosurgical Center between 2007 and 2021 were examined. The recurrence rate and role of PTBE in recurrence in relation to: gender, age, extend of resection, histopathology, tumor volume, location and time of recurrence were evaluated. Follow-up period ranged from 6 to 168 months (median, 87 months) after surgical resection. Results: In our study, the mean age of patients is 47 years, ranged (20-74), at the average (53.5). Male 16 (23.9%), female 51 (76.1%). Mean tumor volume was (32.8cm3), ranged 4.2cm3-143.7cm3. Edema Index (EI) 1; 27 (40.3%) absent edema, and (EI) >1; in 40 (59.7%) present edema. Recurrence rate was 11 (16.4%) patients, 8 (20.0%) patients with PTBE, as compared to 3 (11.1%) patients without PTBE, (p=0,50). Female (8 patients, 15.7%), male (3 patients, 18.7%). The mean age of recurrence was 50.9 years, ranged (21-75), at the average 52.0 years. The mean age in female was 50.8 years, in male 51.0. Bivariate analysis of simultaneous effect of gender and age on SWM recurrence with logistic regression yield both main effect and interaction effect (β gender=M=7.56±6.44, P=0.24; β age=-0.034±0.031, p=0.28; β interaction term=-0.13±0.12, p=0.26). Out of 11 recurrence cases, (2 cases, 9.5%) with small tumour volume, (5 cases, 15.6%) with medium, (3 cases, 33.3%) with large, and (one case, 20.0%) with giant tumour volume. The effect of tumour volume on recurrence rate is insignificant, χ2=2.42, p=0.49.Location of SWM; the recurrence was in (6 cases, 25.0%) of CM location, (2 cases, 25.0%) of SOM and (3 cases, 11.5%) in lateral SWM, (p=0.19). Pathological grade, in the low grade (Gr.I) 7 recurrence cases (13.0%), as compared to 4cases (44.4%) in atypical Gr II, (p=0.01). Simpson grade, the recurrence rate was; 0% in Gr. I; 13.9% in Gr. II; 20.0% in Gr.III; and 33.3% in Gr. IV and 3 cases had died in the early post op (p<0.05). Conclusion: The factors which had a strong impact on the recurrence rate in our study,; i) pathological grade (Gr. II, atypical type) p=0.01 and ii) Simpson grade (extend of tumor resection, p<0.05), while, PTBE (P=0.50), tumor volume (χ2=2.42, p=0.49) and location (χ2=3.37, p=0.19), are weak and non strong factors for recurrence. However, time of recurrence is shorter in patients with PTBE (W=20.5, p=0.092). WHO Gr. II (Spearman’s p=-0.86, p=0.00063) and negligible for Simpson grade (Spearman’s=-0.15, p=0.66).

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

Background and PurposeConsensus regarding the need for adjuvant radiotherapy (RT) in patients with atypical meningiomas (AMs) is lacking. We compared the effects of adjuvant RT after surgery, gross total resection (GTR), and subtotal resection (STR) on progression-free survival (PFS) and overall survival (OS) in patients with AMs, respectively.MethodsWe performed a systematic review and meta-analysis of the literature published in PubMed, Embase, and the Cochrane Library from inception to February 1, 2021, to identify articles comparing the PFS and OS of patients receiving postoperative RT after surgery, GTR and STR.ResultsWe identified 2307 unique studies; 24 articles including 3078 patients met the inclusion criteria. The sensitivity analysis results showed that for patients undergoing undifferentiated surgical resection, adjuvant RT reduced tumor recurrence (HR=0.70, p&lt;0.0001) with no significant effect on survival (HR=0.89, p=0.49). Postoperative RT significantly increased PFS (HR=0.69, p=0.01) and OS (HR=0.55, p=0.007) in patients undergoing GTR. The same improvement was observed in patients undergoing STR plus RT (PFS: HR=0.41, p&lt;0.00001; OS: HR=0.47, p=0.01). A subgroup analysis of RT in patients undergoing GTR showed no change in PFS in patients undergoing Simpson grade I and II resection (HR=1.82, p=0.22) but significant improvement in patients undergoing Simpson grade III resection (HR=0.64, p=0.02).ConclusionRegardless of whether GTR or STR was performed, postoperative RT improved PFS and OS to varying degrees. Especially for patients undergoing Simpson grade III or IV resection, postoperative RT confers the benefits for recurrence and survival.

PATH-35. AKT1(E17K) MUTATIONS ARE FREQUENT GENOMIC EVENTS IN CERVICAL SPINAL MENINGIOMAS

INTRODUCTION Spinal meningiomas represent about one-third of all spine tumors. To date, little is known about the molecular profile of spinal meningiomas and their clinical impact. In this study, we correlate clinical parameters with targeted sequencing findings in a well-characterized cohort of 42 patients with spinal meningiomas. METHODS Samples from 42 spinal meningiomas (31 females and 11 males) were collected. Targeted sequencing for AKT1 E17K hot spot mutations was performed. Furthermore, clinical and imaging data were collected and correlated with the AKT1 mutation status. RESULTS Gross total resection (Simpson grade I /II) was achieved in all patients. The mean follow-up period was 60 months (6 –288 months). None of the patients demonstrated a tumor recurrence. AKT1E17K mutations were detected in 8 patients (19%), in five male and three female patients (p= 0.019). Although the majority of resected meningiomas (n= 28, 66.6%) were located in the thoracic spine, meningiomas originating in the cervical spine harbored significantly more AKT1 E17K mutations (6 out of 14, p= 0.010). Notably, all AKT1 mutated meningiomas arose ventrally or ventrolaterally to the spinal cord. The histologic examination revealed a WHO Grade 1 in 36 meningiomas (85.7%): 21 meningothelial, 8 psammomatous, 5 transitional, 2 fibrous. The remaining six meningiomas were classified as atypical WHO grade 2. Remarkably, AKT1 E17K mutations were significantly related to a meningothelial subtype (p= 0.044). CONCLUSIONS Our molecular study demonstrates that AKT1 E17K mutations are a frequent genomic event in spinal meningiomas. The majority of AKT1 mutated meningiomas occurred in male patients, originate in the cervical spine, and exhibit meningothelial histology.

BIOM-39. METHYLATION AND MUTATION PROFILES IN MENINGIOMA CELL-DERIVED EXTRACELLULAR VESICLE DNA REFLECT EPIGENETIC AND GENOMIC ALTERATIONS IN ORIGINAL TUMORS

The majority of meningiomas are benign but approximately 20% of display an aggressive behavior, resulting in significant patient morbidity and mortality. Standard monitoring after meningioma resection relies on serial MRI examinations, which are time-consuming, expensive and provide no information on molecular alterations that may indicate progression towards a more aggressive tumor. Extracellular vesicles (EVs) are released by tumor cells and contain high molecular weight DNA, rendering circulating EVs a potential biomarker source for non-invasive disease monitoring and for obtaining information on genetic and epigenetic alterations. We quantified EVs in plasma of 46 meningioma patients (n = 29 M1, 12 M2, 5 M3) by nanoparticle tracking analysis and detected significantly higher levels compared to age-matched healthy donors (n = 18). EV concentrations correlated with malignancy grade (p = 0.0049) and with the extent of peritumoral edema (p = 0.0031). Comparisons between paired pre- and postoperative samples revealed that EV levels counts dropped significantly the day after tumor resection and were reduced to normal levels after about one week. Completely resected patients (Simpson grade I) displayed a greater reduction of postoperative EV concentrations than incompletely resected patients. DNA methylation profiling was performed on EVs secreted by cultured meningioma cells, as well as matched cells and original tumors using 850k arrays (n = 7 M1, 5 M2, 3 M3). All EV samples were correctly identified as meningiomas by the Heidelberg classifier, and methylation subclasses were also correctly assigned in almost all cases. t-SNE analysis showed that EVs mapped in close proximity to their corresponding parental cells and tumor tissue. Tumor specific mutations and copy number variations were detected in EV-DNA with high accuracy. Differential quantitative proteomic analysis of EVs, cells and tumors identified shared proteins that could potentially be useful for enriching tumor-derived circulating EVs from biofluids.

NCOG-30. AWAKE CRANIOTOMY FOR MENINGIOMA RESECTION: A STUDY ON THE SAFETY AND TOLERABILITY

Resection of intra-axial brain tumors under scalp block improves safety of surgery, permitting preservation of neurological function and early recovery. However, limited data is available on employing this anesthesia technique for extra-axial tumors particularly meningioma, raising concerns that it may not be feasible due to dural attachment of tumor causing intractable pain and discomfort. We retrospectively analyzed 17 patients who underwent AC for resection of meningioma at our hospital during last 5 years, employing non-probability consecutive sampling. Variables for demographics, and details of diagnosis and surgical procedure were recorded. Eleven of these cases had grade I meningioma, and 6 had grade II meningioma. The mean age of these patients was 45.8 ± 10.5 years. Seizures were the most common presenting complain (n = 7; 41.2%). Eleven patients (58.3%) had convexity meningioma, 4 (33.3%) had parasagittal meningioma and 1 each had a parafalcine and anterior skull-base meningioma. The mean duration of surgery was 180.8 ± 36.2 minutes and the median estimated blood loss was 450 ml (IQR: 225 ml – 737.5 ml). The mean length of stay in the hospital was 3.1 ± 1.3 days. Only 1 patient had a prolonged hospital stay of 7 days because of post-operative seizures. Simpson grade I resection was performed in 6 (41.7%) patients, and grade II resection in 10 (50%) patients. Deterioration in pre-operative neurological exam was not seen in any patient, and no one required emergency intubation, conversion of surgery to general anesthesia, or re-operations. We propose that AC does not pose any significant risk of intra-operative or post-operative pain during meningioma resection, particularly convexity and parasagittal meningioma, and can make surgery possible for patients who are high risk for, or are not willing to undergo general anesthesia.

Purely extradural spinal meningioma: A case report and literature review

Background: Purely extradural spinal meningiomas (ESMs) are exceptionally rare and are often incorrectly diagnosed as metastases, hematological malignancies, or schwannomas. Here, we report a 66-year-old female who presented with an isolated extradural ESM. Case Description: A 66-year-old female presented with a 2.5-year history of a progressive paraparesis (i.e. T7 level) associated with a T5 sensory level. The MR showed a heterogeneously enhancing lesion circumferentially involving the spinal cord from T3 to T5, with left-sided T4/5 foraminal extension. Following a Simpson Grade 2 resection, the patient rapidly recovered full neurological function. Conclusion: The vast majority of the rarely encountered purely ESM are benign. Although gross total resection is optimal, additional adjunctive treatments are available for those treated with subtotal resections.

Simpson Grade I Resection of Type II Clinoidal Meningiomal Through Cranio-orbital Zygomatic Approach: 2-Dimensional Operative Video

Clinoidal meningiomas have been considered as a separate entity with distinguishing clinical, radiological, and surgical considerations.1–2 Surgical mortality and morbidity associated with anterior clinoidal meningiomas has remained high in the past, with radical resection considered unattainable.3 However, the extent of surgical removal is clearly the most determining factor in tumor recurrence and progression. Clinoidal meningiomas have been classified into 3 types according to their origin from the dura surface of the anterior clinoid and subsequent arachnoidal rearrangement around the parasellar neurovascular structures.1 In type II, there is an arachnoidal plane that allows the tumor dissection from the encased carotid artery and its branches and the optic nerve. In this type, the involvement of the cavernous sinus is limited to the external wall, which can also be removed. Hence, these tumors are amenable to Simpson grade I resection (tumor, dura, and bone). Approaching through the multidirectional axis provided by the cranio-orbital zygomatic approach allows safe exposure of the tumor and vascular control.4-5 Proximal carotid control is obtained in the petrous carotid canal, the invaded anterior clinoid is removed by and large extradurally, and the Sylvian fissure is split wide open to establish dissecting planes with the middle cerebral artery branches. The optic canal is opened, and tumor extension is removed.6 The invaded outer wall of the cavernous sinus and superior orbital fissure is removed. We demonstrate this technique in a 48-yr-old patient who consented for surgery and publication of images. All images at 2:27, center and right images at 2:46, and all images at 2:58, reused with permission from LWW, from Al-Mefty, Operative Atlas of Meningiomas. Left image at 2:46 reprinted from Surg Neurol, Vol 60/issue 6, Arnautović KI, Al-Mefty O, Angtuaco E, A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms, pp. 504–520, Copyright 1998, with permission from Elsevier. Image at 8:21 reprinted from Al-Mefty,1 Clinoidal meningiomas, by permission from JNSPG.

Progression Free -survival According to Simpson Grade Resection and Histological Types of Meningiomas in the Mexican Population Progression Free-survival of Meningiomas in the Mexican Population

Introduction: Meningiomas are the most common primary central nervous system (CNS) tumors, with an incidence of 8.14 per 100,000 habitants. They represent 30% of all adult primary brain tumor diagnoses in the United States in contrast to Latin America with 50%. In Mexico, there are no epidemiological trends of meningiomas or other CNS tumors. Simpson resection grade and WHO grade are the prognostic factors with the greatest effect. In this paper, we describe the correlation between the survival free of disease and the gross total resection with its histological type according to Simpson’s grading scale. Materials and methods: A descriptive, analytical, retrospective, case-control study was conducted in two public third -level hospitals and three second- level hospitals in two cities of Mexico, (Mexico City and Guadalajara, Jalisco in a period of 10 years (2010-2020). An analysis of measures of central tendency was performed for age, sex, location, histological type, and postsurgical Simpson grade.Results: 26 patients of 179 had recurrence. Among the total recurrences, 15.4% were Simpson 1, 69.2%Simpson 2, and 15.4%Simpson 3. The survival for Simpson 1 was 142.0 months, Simpson 2 90.32 months, and Simpson 3 69.13 months. According to the histological type, the meningiomas with the lowest survival were the microcystic ones with 60 months, followed by the atypical ones with 90.4 months, and the psammomatous ones with 99.8 months. Conclusion: Surgical resection and the histological type are factors that affect progression free -survival. The Mexican population presents characteristics similar to those described in world literature.Importance of the study: This is the first study of its kind in the Mexican population and lays the foundations for future studies in the Latin American population.

Posterior interhemispheric occipital transtentorial approach for resection of a falcotentorial meningioma

Falcotentorial meningiomas arise along the junction of the falx cerebri and the tentorium cerebelli. The authors present a woman in her 60s with an incidentally discovered falcotentorial meningioma, approximately 3 cm in diameter, resected with a torcular craniotomy and posterior interhemispheric approach. The galenic complex was dissected away from the tumor. In the final view, the bilateral internal cerebral veins and basal veins of Rosenthal were seen. A Simpson grade I resection was achieved. The patient experienced transient contralateral hemianopsia and was discharged home. At 1-year follow-up, her neurological examination findings were unremarkable, and there was no radiographic evidence of tumor. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2125.

The surgical challenge of ossified ventrolateral spinal meningiomas: tricks and pearls for managing large ossified meningiomas of the thoracic spine

The authors present an illustrative technical note on microsurgical resection of ventrolateral completely ossified spinal meningiomas (OSMs) and a literature review of the surgical management of calcified spinal meningiomas or OSMs. These tumors are surgically demanding due to their solid consistency, especially when in a ventrolateral location with dislocation of the spinal cord. A challenging case with significant thoracic cord compression and displacement is described. Due to the firm consistency and the ventrolateral localization of the meningioma, a piecemeal resection was necessary. This could have resulted in a free-floating tumor remnant adherent to the spinal cord, impeding safe tumor resection. To avoid such a remnant, an anchoring burr hole was drilled at the border between the spinal cord and the adamantine tumor mass. Then, a microdissector was placed within the anchoring burr hole and the tumor was gently pulled laterally while drilling away the medial parts of the ossified tumor. This procedure was repeated until separation of the tumor from the spinal cord was possible and a gross-total resection (Simpson grade II) was manageable. Throughout the procedure, continuous intraoperative neurophysiological monitoring was performed.