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Background and Importance: Spheno-orbital meningiomas (SOMs) pose a challenge to the skull base neurosurgeon because of their variable presentation and involvement of critical structures within the orbit. There is no consensus on optimal management of these patients and how to achieve maximal safe resection. The authors share an illustrative case with an accompanying video to demonstrate their aggressive approach to resect SOMs and their intraorbital components., Clinical Presentation: A 75-year-old-woman presented with progressive vision loss and proptosis. Magnetic resonance imaging was consistent with a large, left-sided sphenoid wing meningioma with extension to the orbital wall and compression of the optic nerve medially. The patient elected to undergo surgical excision and optic nerve decompression. She did well postoperatively with resolution of proptosis and good resection margins on follow-up imaging., Conclusion: Aggressive resection of SOMs is possible with an understanding of the underlying anatomy. Familiarity with the orbit can facilitate a maximal safe resection with optic nerve decompression., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Aims: The objective of our study was to establish and verify a novel combined model based on multiparameter magnetic resonance imaging (MRI) radiomics and clinical features to distinguish intraspinal schwannomas from meningiomas., Materials and Methods: This research analyzed the preoperative magnetic resonance (MR) images and clinical characteristics of 209 patients with intraspinal tumors who received tumor resection at three institutions. 159 individuals from institutions 1 and 2 were randomly assigned into a training group (n=111) and a test group (n=48) in a 7-3 ratio. A nomogram was constructed using the training cohort and was internally and externally verified in the test cohort and an independent validation cohort (n=50). Model performance was assessed utilizing the area under the curve (AUC) of receiver operating characteristics (ROC), decision curve analysis (DCA), and calibration curves., Results: The nomogram exhibited superior predictive efficacy in distinguishing between spinal schwannomas and meningiomas when compared to both the radiomics model and the clinical model. The nomogram yielded AUCs of 0.994, 0.962, and 0.949 in the training, test, and external validation cohorts, respectively, indicating its exceptional differentiating ability. The DCAs demonstrated that the nomogram yielded the best net benefit. The calibration curves indicated that the nomogram got good agreement between the predicted and the actual observation., Conclusion: This research suggests that the nomogram incorporating clinical and radiomic features may be an effective auxiliary tool for distinguishing between intraspinal schwannomas and meningiomas, and has important clinical significance for clinical decision-making and prognosis prediction., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background and Objectives: Cranial reconstruction presents a significant challenge in cases involving pathologies with skull invasion, and various techniques have been used, including the intraoperative shaping of titanium mesh and the manual sculpting of bone cement serving as surrogates for the excised bone graft. In the context of prefabricated patient-specific implants (PSIs) for cranioplasty, precise surgical execution of craniotomies is paramount. This ensures optimal congruity between the implant and the defect created during the craniotomy, leading to a successful single-stage procedure encompassing both bone removal and reconstruction. This article presents a meticulous method for achieving such high-fidelity craniotomy and subsequent cranioplasty using PSIs in a single-stage surgery., Methods: The procedure was implemented for 2 cases of meningiomas with osseous invasion. Through meticulous preoperative planning, the craniotomy template and implant were designed using computer-assisted design and manufactured on a 3-dimensional printer using the patient's computed tomography scans. Intraoperative fabrication of sterile polymethyl methacrylate replicas was achieved through the creation of silicone molds and subsequent injection molding techniques. Predesignated screw holes facilitated neuronavigation-assisted positioning of the template, aligning it accurately with the target site using registration points. Mini-screws firmly secured the template to the skull. Guided by the template, a craniotomy router performed the bone resection. On completion, the implant was affixed into place using plates and screws., Results: This technique demonstrably facilitated a cost-effective, streamlined and precise application of prefabricated PSIs within a single-stage craniotomy-cranioplasty procedure. Subjective patient reports indicated high levels of satisfaction with the outcome., Conclusion: The template routed patient-specific implant 1-stage cranioplasty technique refines previous approaches through precise template localization on the skull, enabling an accurate craniotomy to match a prefabricated PSI. This single-stage procedure rivals hand-shaped methods in aesthetics and compares with the outcomes of 2-stage PSI cranioplasties. Additional studies are needed to validate our results., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: This study aimed to examine the effect of postoperative radiotherapy on survival outcomes in patients with malignant meningiomas., Methods: We identified patients with malignant meningioma diagnosed between 2007 and 2018 using the Taiwan Cancer Registry and followed them up using the death registry. Survival was compared between patients with and without adjuvant radiotherapy. The potential confounding factors evaluated in this study included age, sex, comorbidities, and the Charlson Comorbidity Index (CCI)., Results: The analysis included 204 patients; 94 (46%) received adjuvant radiotherapy. The two groups had similar sex distributions (p = 0.53), mean age (p = 0.33), histologic subtype (p = 0.13), and CCI (p = 0.62). The prognosis of malignant meningioma was poor, with a median overall survival (OS) of 2.4 years. The median OS was 3.0 years (interquartile range (IQR) [1.4-6.1], and 2.0 years (IQR [0.5-3.9]) in the radiotherapy and non-radiotherapy groups, respectively (p = 0.001). However, Kaplan-Meier curves with the log-rank test showed no significant difference in OS between the two groups (p = 0.999). Controlling for age group, sex, histologic subtype, treatment, comorbidities, and CCI, adjuvant radiotherapy did not impart a survival benefit (hazard ratio [HR] = 0.87; 95% confidence interval [CI]: 0.6‒1.26); however, only factor of higher comorbidity score (HR = 2.03, 95%CI: 1.04‒3.94) was associated with unfavorable survival., Conclusion: This population-based retrospective analysis suggests that the role of radiotherapy remains unclear and underscores the need for randomized clinical trials to assess the usefulness of adjuvant radiotherapy in malignant meningioma., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Aims: WHO Grade 3 (G3) meningiomas are rare tumours with limited data to guide management. This retrospective study documents UK management approaches across 14 centres over 11 years., Materials and Methods: Patients with WHO G3 meningioma between 01/01/2008 and 31/12/2018 were identified. Data were collected on demographics, management strategy, adjuvant radiotherapy, approach in recurrence setting and survival., Results: 84 patients were identified. 21.4% transformed from lower-grade disease. 96.4% underwent primary surgical resection, with 20.8% having evidence of residual disease on their post-op MRI. 59.3% of patients underwent adjuvant radiotherapy (RT) following surgical resection. Overall median PFS and OS were 12.6 months and 28.2 months, respectively. Median OS in the group who underwent complete surgical resection was 34.9 months, compared to 27.5 months for those who had incomplete resection (HR 0.58, 95% CI 0.27-1.23, p = 0.15). Median OS was 33.1 months for those who underwent adjuvant RT and 14.0 months for those who did not (HR 0.48, 95% CI 0.27-0.84, p = 0.004). Median adjuvant RT dose delivered was 60Gy (range 12Gy-60Gy), 45.8% of adjuvant RT was delivered using IMRT. At disease relapse, 31% underwent salvage surgery and 29.3% underwent salvage RT. Of those treated with salvage RT, 64.7% were re-treats and all were treated with hypofractionated RT., Conclusion: Surgery continues to be the preferred primary management strategy. Post-operative MRI within 48 hours is indicated to assess presence of residual disease and guide further surgical options. Adjuvant radiotherapy plays an important part of the management paradigm in these patients with the data supporting an attached survival advantage. Further surgery and re-irradiation is an option in the disease recurrence setting with radiosurgery frequently utilised in this context., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Background: The Simpson grading scale assumes dural resection (grade I) is more effective against recurrence than coagulation (grade II). However, the results of recent studies have raised doubts about this effectiveness in spinal meningiomas. Therefore, we aimed to perform a meta-analysis comparing outcomes between Simpson grades I and II in spinal meningiomas., Methods: According to the PRISMA statement, we systematically searched PubMed, EMBASE, and Web of Science for studies involving patients with spinal meningiomas who underwent Simpson grades I, II, III, or IV. Outcomes were radiological tumor recurrence, postoperative neurological deficits, and procedure-related complications., Results: We included 54 studies with a total of 3334 patients. Simpson grades I, II, III, and IV were performed in 674 (20%), 2205 (66%), 254 (8%), and 201 (6%) patients, respectively. The follow-up ranged from 9 to 192 months, and 95.4% of all tumors were WHO grade 1. There was no difference in radiological tumor recurrence (OR 0.80, 95% CI: 0.46-1.36, P = 0.41; I 2  = 0%), postoperative neurological deficits (OR 0.74, 95% CI: 0.32-1.75, P = 0.50; I 2  = 0%) or procedure-related complications (OR 2.22, 95% CI: 0.80-6.13, P = 0.12; I 2  = 3%) between Simpson grades I and II. Furthermore, no significant difference in postoperative neurological deficits or procedure-related complications was detected when comparing all Simpson's to each other. However, radiological tumor recurrences in Simpson I and II were significantly lower than in III and IV, with Simpson III outperforming IV (OR 0.19, 95% CI: 0.09-0.40, P < 0.01; I 2  = 0%)., Conclusion: Simpson grade I is not more effective than grade II in any outcome, although both are superior to III and IV in tumor recurrence. Our results might suggest that dural coagulation is preferable over resection when the latter carries a higher risk of complications., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

This study reviews recent progress in the surgical treatment of Rathke's cleft cysts (RCCs) and Sellar region meningiomas, based on findings from three key studies. RCCs are benign, fluid-filled remnants from pituitary gland development that are usually asymptomatic and found by chance. However, surgical intervention is needed when they become symptomatic or increase in size. Research by Stefan Linsler et al. and others examines various surgical methods, including transcranial keyhole and transsphenoidal techniques for RCCs, and endoscopic endonasal and supraorbital keyhole approaches for Sellar meningiomas. The results show that both transcranial keyhole and transsphenoidal surgeries for RCCs have high success rates with no recurrences over 5.7 years, although the keyhole approach has fewer complications. For Sellar meningiomas, the choice between endoscopic endonasal and supraorbital keyhole techniques should be based on tumor characteristics, highlighting the importance of surgeon proficiency in both methods. These studies emphasize the need for personalized treatment strategies tailored to patient and tumor characteristics and highlight the importance of ongoing surgical skill development and further research to refine minimally invasive techniques. This study highlights the crucial role of personalized surgical approaches in improving outcomes for patients with RCCs and Sellar region meningiomas., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Our purpose was to determine the utility of [68Ga]-DOTATATE PET/MRI in meningioma response assessment following radiosurgery., Methods: Patients with meningioma prospectively underwent postoperative DOTATATE PET/MRI. Co-registered PET and gadolinium-enhanced T1-weighted MRI were employed for radiosurgery planning. Follow-up DOTATATE PET/MRI was performed at 6-12 months post-radiosurgery. Maximum absolute standardized uptake value (SUV) and SUV ratio (SUVRSSS) referencing superior sagittal sinus (SSS) blood pool were obtained. Size change was determined by Response Assessment in Neuro-Oncology (RANO) criteria. Association of SUVRSSS change magnitude and progression-free survival (PFS) was evaluated using Cox regression., Results: Twenty-seven patients with 64 tumors (26% World Health Organization [WHO]-1, 41% WHO-2, 26% WHO-3, and 7% WHO-unknown) were prospectively followed post stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT; mean dose: 30 Gy, modal dose 35 Gy, mean of 5 fractions). Post-irradiation SUV and SUVRSSS decreased by 37.4% and 44.4%, respectively (P < .0001). Size product decreased by 8.9%, thus failing to reach the 25% significance threshold as determined by RANO guidelines. Mean follow-up time was 26 months (range: 6-44). Overall mean PFS was 83% and 100%/100%/54% in WHO-1/-2/-3 subcohorts, respectively, at 34 months. At maximum follow-up (42-44 months), PFS was 100%/83%/54% in WHO-1/-2/-3 subcohorts, respectively. Cox regression analyses revealed a hazard ratio of 0.48 for 10-unit reduction in SUVRSSS in the SRS cohort., Conclusions: DOTATATE PET SUV and SUVRSSS demonstrated marked, significant decrease post-radiosurgery. Lesion size decrease was statistically significant; however, it was not clinically significant by RANO criteria. DOTATATE PET/MR thus represents a promising imaging biomarker for response assessment in meningiomas treated with radiosurgery., Clinicaltrials.gov Identifier: NCT04081701., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: A primary pulmonary meningioma is an extremely rare entity. Primary pulmonary meningiomas manifested with a ground glass nodule are a very rare occurrence in clinical practice., Case Presentation: In this study, we report a case of a primary pulmonary meningioma with atypical computed tomography features. A 59-year-old Han Chinese female came to our hospital for treatment and reported that her physical examination revealed a ground glass nodule in the right lung for over 3 months. The histologic result revealed a primary pulmonary meningioma. The patient underwent a thoracoscopic lung wedge resection of the right upper lobe for a ground glass nodule. After 1 year of follow-up, the patient is still alive without evidence of metastasis or recurrence., Conclusions: Primary pulmonary meningiomas could have a variety of radiological findings. As there are no specific radiologic features for the diagnosis of primary pulmonary meningiomas, complete resection of the lesion is required for both diagnosis and treatment. It is necessary to note the imaging features of primary pulmonary meningiomas, presenting as a ground glass nodule; this rare tumor should be considered in differential diagnoses., (© 2024. The Author(s).)

Purpose: Meningeal solitary fibrous tumour (SFT) and haemangiopericytoma (HPC) are uncommon tumours that have been merged into a single entity in the last 2021 WHO Classification of Tumors of the Central Nervous System. To describe the epidemiology of SFT/HPC operated in France and, to assess their incidence., Methods: We processed the French Brain Tumour Database (FBTDB) to conduct a nationwide population-based study of all histopathologically confirmed SFT/HPC between 2006 and 2015., Results: Our study included 399 SFT/HPC patients, operated in France between 2006 and 2015, in one of the 46 participating neurosurgical centres. The incidence reached 0.062, 95% CI[0.056-0.068] for 100,000 person-years. SFT accounted for 35.8% and, HPC for 64.2%. The ratio of SFT/HPC over meningioma operated during the same period was 0.013. SFT/HPC are about equally distributed in women and men (55.9% vs. 44.1%). For the whole population, mean age at surgery was 53.9 (SD ± 15.8) years. The incidence of SFT/HPC surgery increases with the age and, is maximal for the 50-55 years category. Benign SFT/HPC accounted for 65.16%, SFT/HPC of uncertain behaviour for 11.53% and malignant ones for 23.31%. The number of resection progresses as the histopathological behaviour became more aggressive. 6.7% of the patients with a benign SFT/HPC had a second surgery vs.16.6% in case of uncertain behaviour and, 28.4% for malignant SFT/HPC patients., Conclusion: Meningeal SFT and HPC are rare CNS mesenchymal tumours which both share common epidemiological characteristics, asserting their merging under a common entity. SFT/HPC incidence is less that one case for 1 billion per year and, for around 100 meningiomas-like tumours removed, one SFT/HPC may be diagnosed. SFT/HPC are equally distributed in women and men and, are mainly diagnosed around 50-55 years. The more aggressive the tumour, the higher the probability of recurrence., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Spinal intradural tumors are rare and heterogeneous in histological type, aggressiveness, and symptomatology, and there is a lack of data about them. This study investigated the epidemiological features of spinal intradural tumors., Methods: This retrospective analysis included patients with spinal intradural tumors who underwent surgical treatment at the Myelopathy and Spondylosis Ward Beijing Jishuitan Hospital between January 2012 and December 2022., Results: This study included 1321 patients [aged 47.19 ± 14.90 years, 603 (45.65%) males] with spinal intradural tumors. The most common histological subtype was schwannoma [n = 511 (38.68%)], followed by spinal meningioma [n = 184 (13.93%)] and ependymoma [n = 101 (7.65%)]. Fifteen (1.14%) patients were diagnosed with metastatic spinal intradural tumors as a presentation of another primary cancer type. The spinal intradural tumors were mostly found in the lumbar region [n = 436 (33.01%)], followed by the thoracic vertebrae [n = 390 (29.52%)], cervical vertebrae [n = 154 (11.66%)], and thoracolumbar region [n = 111 (8.40%)]. Schwannomas mostly affected the lumbar region [n = 256 (52.64%)], spinal meningiomas in the thoracic region [n = 153 (83.15)], and ependymomas in the lumbar region [56 (55.45%)]. The de novo metastases were mostly found in the lumbar region [n = 8 (53.33%)]., Conclusion: According to the results of our single-center study, the most common spinal intradural tumor in Northern China is schwannoma, followed by spinal meningioma and ependymoma., (© 2024. The Author(s).)

Background: Patients with spinal meningioma may present preoperatively with paralysis and sensory deficits. However, there is a paucity of detailed evaluations and a lack of consensus regarding imaging findings that are predictive of neurological symptoms in patients with spinal meningioma., Methods: Herein, a total of 55 patients who underwent surgical resection of spinal meningiomas in eight hospitals between 2011 and 2021 were enrolled. Patient characteristics, degree of muscle weakness, sensory disturbances, and the presence of bowel/bladder dysfunction (BBD) before surgical treatment were evaluated using medical records. Patients with American Spinal Injury Impairment Scale grades A-C and the presence of BBD were classified into the paralysis (+) group. Patients with sensory disturbances were assigned to the sensory disturbance (+) group. Based on magnetic resonance (MR) and computed tomography images, the tumor location was classified according to the spinal level and its attachment to the dura mater. To evaluate tumor size, the tumor occupation ratio (OR) was calculated using the area and distance measurement method in horizontal MR images, and the maximum length and area of the tumor in the sagittal plane were measured., Results: Of all patients, 85 % were women. The mean age of patients at surgery was 69.7 years. Twenty-eight (51 %) and 41 (75 %) patients were classified into the paralysis (+) and sensory disturbance (+) groups, respectively. The average tumor length and area in the sagittal plane were 19.6 mm and 203 mm 2 , respectively; OR-area and diameters were 70.3 % and 72.3 %, respectively. In univariate analyses, tumor length and area in the sagittal plane were significant risk factors for paralysis. OR-diameter, symptom duration, and a low MIB-1 index correlated with sensory disturbances. Multivariate logistic regression analysis demonstrated that the area and length of the tumor in the sagittal plane were significantly correlated with paralysis, whereas the OR-diameter and symptom duration significantly correlated with sensory disturbances. The cut-off values for the area and length of the tumor in the sagittal plane to predict paralysis were 243 mm 2 and 20.1 mm, respectively., Conclusions: Preoperative paralysis in patients with spinal meningiomas was significantly associated with sagittal tumor size than with high tumor occupancy in the horizontal plane. Sensory disturbances were associated with high occupancy in the horizontal plane. Patients with spinal meningiomas > 20 mm in length or 243 mm 2 in area in the sagittal plane are at risk of developing paralysis and could be considered for surgery even in the absence of paralysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To examine demographic and clinical characteristics and their association with survival in grade 2 and 3 pediatric meningiomas in a large cohort using the National Cancer Database (NCDB)., Methods: We conducted a comprehensive analysis using data from NCDB between 2004 to 2018. Tumor-specific data included tumor grade and size. Treatment details, including surgical resection, extent of resection, and radiotherapy, were gathered. Our analytic approach incorporated logistic and Poisson regression, Kaplan-Meier survival estimates, and Cox proportional hazards models., Results: Among the included 239 patients aged 0-21 years, age category distribution was significantly different between grade 2 and grade 3 tumors (p = 0.018). For grade 2 meningiomas, 51.5% of patients were female, and 76.7% were white. 85.3% of patients with grade 2 meningiomas underwent surgical resection, of which 67% underwent gross total resection. Overall survival (OS) was significantly different between resected and non-resected patients (p = 0.048). Uninsured patients were over seven times as likely to have prolonged length of stay (LOS) versus those with private insurance (OR = 7.663, p = 0.014). For grade 3 meningiomas, 51.4% of patients were male, and 82.9% were white. 91.4% of patients with grade 3 meningiomas underwent surgical resection, of which 53.3% underwent subtotal resection. OS was not significantly different between resected and non-resected patients (p = 0.659)., Conclusion: In summary, there were significant differences in age, maximum tumor dimension, unplanned readmission, radiotherapy, and treatment combinations between grade 2 and 3 meningiomas. These findings highlight the intricacies of managing pediatric meningiomas and emphasize the necessity for tailored therapeutic approaches to enhance outcomes in the future., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Objectives: Surgery of posterior fossa meningiomas is extremely challenging even for experienced skull base surgeons because of the close proximity to cranial nerves and tight spaces. Endoscope-assisted surgery for posterior fossa meningiomas can enable a high degree of tumor resection even when using small approaches. This study describes the advantage of endoscope-assisted microneurosurgery in resection of posterior fossa skull base meningiomas and the clinical outcome., Methods: All endoscope-assisted surgeries for resection of posterior fossa meningiomas performed between 2002 and 2016 in our department were retrospectively analyzed. For data acquisition, the patient files were used. Tumor size and extent of resection were evaluated on pre- and postoperative magnetic resonance imaging. The value of endoscope assistance was assessed according to the intraoperative videos and the surgical notes. Complications and long-term outcomes were evaluated., Results: We identified 39 female and 10 male patients. The mean age of the patients at the time of surgery was 55 years, ranging from 25 to 78 years. The mean follow-up was 93.8 months. A total of 41% of the tumors were large to giant. The retrosigmoid approach was used in most patients (45). A gross total resection could be achieved in 38 patients (78%). In 11 patients (22%), a near total resection was performed. In 27 patients (55%), a hidden residual tumor, which could not been visualized with the operating microscope, was identified with the endoscope. In 6 patients (22.2%), the internal auditory canal was visualized, in 9 patients (33.3%), the Meckel's cave was visualized, and in 5 patients (18.5%), both were visualized under endoscope assistance. In 26 of those patients (96.3%), the residual tumor was resected under endoscopic view., Conclusion: Endoscope-assisted surgery for posterior fossa skull base meningiomas enables a high degree of tumor resection, avoids more invasive skull base approaches, and reduces the amount of cerebellar retraction., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Objective: Surgery remains the first line treatment for meningiomas and can benefit from fluorescence-guided surgical techniques such as second-window indocyanine green (SWIG). In the current study, we compared the use of the standard SWIG dose of 5.0 mg/kg relative to 2.5 mg/kg indocyanine green (ICG) in meningioma patients., Methods: Patients were prospectively enrolled in an IRB-approved study of SWIG and received either the standard dose of 5.0 mg/kg or a reduced dose of 2.5 mg/kg of ICG around 24 h prior to their surgery. Intraoperative near-infrared fluorescence imaging was performed with exo- and endoscopic systems. Signal-to-background ratio (SBR) was calculated to quantify fluorescence and was compared between 5.0 mg/kg and 2.5 mg/kg ICG. All patients received pre-operative MRI and, in select cases, the pre-operative MRI was correlated to intraoperative fluorescence imaging., Results/discussion: In the current study, we found no significant difference in the SBR of meningiomas in patients that were administered with either 5.0 mg/kg or 2.5 mg/kg ICG. However, in five patients that received the standard-dose SWIG regimen of 5.0 mg/kg ICG we observed dose-related fluorescence quenching - referred to as "inversion" - that interfered with tumor visualization during fluorescence-guided surgery (FGS). When correlated to pre-operative MRI, a similar rim pattern was observed around the primary tumor on T 2 FLAIR, which, in retrospect, could be used as a predictor for inversion during FGS in meningioma patients receiving standard-dose ICG., Conclusion: This study demonstrated that a reduced ICG dose was as effective as standard-dose SWIG in meningioma patients. We therefore recommend to adjust the standard ICG dose for meningioma patients to 2.5 mg/kg particularly when rim enhancement is observed on pre-operative T 2 FLAIR., (Copyright © 2024. Published by Elsevier B.V.)

We present a 2-dimensional operative video (Video 1) of a suboccipital retrosigmoid approach for an anteromedial tentorial meningioma with a specific focus on the use of a surgical exoscope. The patient is a 50-year-old woman who presented to emergency room with a 6-month history of nausea, dizziness, and gait imbalance secondary to a 2.5-cm homogenously enhancing mass originating from the anteromedial tentorium on the right side with associated brainstem compression. Retrosigmoid craniotomy was selected due to the favorable surgical corridor for resection and lower risk of cerebrospinal fluid leak, hearing loss, and seizures compared with other approaches. 1-5 The patient consented to the procedure. Video 1 emphasizes the advantages of the exoscope compared with the microscope in optimizing surgeon efficiency, ergonomics, and comfort. 6 The unique operating room setup associated with exoscope use is highlighted. The patient underwent uncomplicated gross total resection with a mild trochlear nerve palsy noted postoperatively that was resolved at follow-up. 7 ., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Schwannomas and meningiomas are the most common intradural extramedullary spinal tumors; however, differentiating between them using magnetic resonance imaging (MRI) is a frequent challenge. In this study, we aimed to investigate the use of the contrast ratio (CR) as a quantitative MRI method in the differentiation of schwannomas and meningiomas., Methods: We analyzed the data of patients with intradural extramedullary spinal tumors who underwent surgery and were diagnosed with either schwannomas or meningiomas by histopathological analysis. Regions of interest were set for the entire spinal tumor on T2-weighted sagittal MRI. To obtain the CR values of spinal tumors (CR tumor ), we used the signal intensity (SI) values of the tumor (SI tumor ) and spinal cord (SI cord ) according to the following formula: [CR tumor  = (SI tumor -SI cord )/(SI tumor +SI cord )]., Results: The study included 50 patients (23 males and 27 females) with a mean age of 61.5 years old (11-85 years old). Histopathological analysis revealed that 33 and 17 patients were diagnosed with schwannomas and meningiomas, respectively. The mean CR values of the schwannomas and meningiomas were 0.3040 ± 0.1386 and 0.0173 ± 0.1929, respectively. The CR value of the schwannomas was statistically significantly higher than that of meningiomas (P < 0.01). The cutoff CR value obtained from the receiver operating characteristic curve was 0.143, with a specificity and sensitivity of 90.9% and 88.2%, respectively. Furthermore, the value for the area under the receiver operating characteristic curve was 0.925 (95% confidence interval: 0.852-0.998)., Conclusions: The evaluation of CRs by using MRI to distinguish between schwannomas and meningiomas is a beneficial quantitative tool., (Copyright © 2024. Published by Elsevier Inc.)

Objective: 11 C-Methionine positron emission tomography (MET-PET) is used for stereotactic radiotherapy planning in meningioma patients. The role of MET-PET during subsequent follow-up (FU) is unclear. We analyzed the uptake of 11 C-Methionine before and after stereotactic radiotherapy (SRT) in patients with a complex meningioma and investigated if there was a difference between patients with progressive disease (PD) and stable disease (SD) during FU., Methods: This retrospective study investigates 62 MET-PETs in 29 complex meningioma patients. Standardized uptake value (SUV) max and SUV peak tumor-to-normal ratios (T/N-ratios) were calculated, comparing the tumor region with both the mirroring intracranial area and the right frontal gray matter. The difference in 11 C-Methionine uptake pre- and post-SRT was analyzed, as well as the change in uptake between PD or SD., Results: Median (IQR) FU duration was 67 months (50.5-91.0). The uptake of 11 C-Methionine in meningiomas remained increased after SRT. Neither a statistically significant difference between MET-PETs before and after SRT was encountered, nor a significant difference in one of the four T/N-ratios between patients with SD versus PD with median (IQR) SUV max T/N R front 2.65 (2.13-3.68) vs 2.97 (1.55-3.54) [p = 0.66]; SUV max T/N mirror 2.92 (2.19-3.71) vs 2.95 (1.74-3.60) [p = 0.61]; SUV peak T/N R front 2.35 (1.64-3.40) vs 2.25 (1.44-3.74) [p = 0.80]; SUV peak T/N mirror 2.38 (1.91-3.36) vs 2.35 (1.56-3.72) [p = 0.95]., Conclusions: Our data do not support use of MET-PET during FU of complex intracranial meningiomas after SRT. MET-PET could not differentiate between progressive or stable disease., (© 2024. The Author(s).)

Purpose: Frailty is an independent risk factor for adverse postoperative outcomes following intracranial meningioma resection (IMR). The role of the Risk Analysis Index (RAI) in predicting postoperative outcomes following IMR is nascent but may inform preoperative patient selection and surgical planning., Methods: IMR patients from the Nationwide Inpatient Sample were identified using diagnostic and procedural codes (2019-2020). The relationship between preoperative RAI-measured frailty and primary outcomes (non-home discharge (NHD), in-hospital mortality) and secondary outcomes (extended length of stay (eLOS), complication rates) was assessed via multivariate analyses. The discriminatory accuracy of the RAI for primary outcomes was measured in area under the receiver operating characteristic (AUROC) curve analysis., Results: A total of 23,230 IMR patients (mean age = 59) were identified, with frailty statuses stratified by RAI score: 0-20 "robust" (R)(N = 10,665, 45.9%), 21-30 "normal" (N)(N = 8,895, 38.3%), 31-40 "frail" (F)(N = 2,605, 11.2%), and 41+ "very frail" (VF)(N = 1,065, 4.6%). Rates of NHD (R 11.5%, N 29.7%, F 60.8%, VF 61.5%), in-hospital mortality (R 0.5%, N 1.8%, F 3.8%, VF 7.0%), eLOS (R 13.2%, N 21.5%, F 40.9%, VF 46.0%), and complications (R 7.5%, N 11.6%, F 15.7%, VF 16.0%) significantly increased with increasing frailty thresholds (p < 0.001). The RAI demonstrated strong discrimination for NHD (C-statistic: 0.755) and in-hospital mortality (C-statistic: 0.754) in AUROC curve analysis., Conclusion: Increasing RAI-measured frailty is significantly associated with increased complication rates, eLOS, NHD, and in-hospital mortality following IMR. The RAI demonstrates strong discrimination for predicting NHD and in-hospital mortality following IMR, and may aid in preoperative risk stratification., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: This study aimed to describe the extended intradural anterior transpetrous approach (ATPA) and its usefulness for the surgical resection of petroclival meningiomas (PCMs) of the cerebellopontine angle (CPA) and/or diaphragma sellae (DS) extension., Methods: Between January 2017 and December 2019, a total of 22 patients with PCMs extending to the CPA/or DS underwent surgery via extended intradural ATPA by the senior author (Xr.X.). We retrospectively analysed the clinical data, radiological findings, surgical treatment, complications, and outcomes of patients and discussed the operative technique., Results: In 22 patients, the tumours were gross totally removed (Simpson I and II) in 18 patients (81.8%), subtotally (Simpson III) in 3 patients (13.6%), and partially (Simpson IV) in 1 patient (4.5%). One patient died 48 days after the operation, and no recurrence was found in 21 patients during a median follow-up of 26 months. Postoperative complications included in abducens nerve palsy in 12 patients with recovery in 10 patients, facial numbness in 4 patients with recovery in 3 patients, and hemiplegia and oculomotor nerve palsy in 1 patient each with recovery in all patients. The postoperative MRI showed temporal lobe oedema but no clinical symptoms in 3 patients., Conclusion: Extended intradural ATPA is an alternative approach for PCMs of the CPA and/or DS extension. The single approach can expose both the sellar region and the posterolateral area of the IAC, which is advantageous for extended intradural ATPA.

Cranioplasty with titanium mesh provides a stable and cosmetically sound option for the correction of extensive skull bone defects following trauma or tumour surgery with osseous involvement. Meningiomas are for the most part benign lesions that are amenable to surgical cure, however lesions with extradural extension pose additional challenges not only due to increased technical difficulty in achieving gross total resection but also because of distinct biological behaviour. We describe the case of a 43-years-old woman that had been submitted to gross total resection of a WHO grade I falcine and superior sagittal sinus secretory meningioma with extradural and bone extension and cranioplasty with a titanium mesh who had a recurrence 4 years later as two tumour masses on top of the titanium mesh with no adjacent soft tissue invasion, and without dural involvement. To our knowledge, this is the first reported case of meningioma growth on top of titanium cranioplasty material. Seeded or incompletely removed tumoral cells might have exploited the biocompatibility of titanium to promote tumour regrowth.

Objective: Surgical resection is the mainstay of treatment for WHO grade 2 meningioma. Fractionated radiation therapy (RT) is frequently used after surgery, though many centers utilize stereotactic radiosurgery (SRS) for recurrence or progression. Herein, we report disease control outcomes from an institutional cohort with adjuvant fractionated RT versus salvage SRS., Methods: We identified 32 patients from an institutional database with WHO grade 2 meningioma and residual/recurrent tumor treated with either SRS or fractionated RT. Patients were treated between 2007 and 2021 and had at least 1 year of follow-up. Kaplan-Meier estimators were used to determine gross tumor control (GTC) and intracranial control (IC). Univariate Cox proportional hazards models using biologically effective dose (BED) as a continuous parameter were used to assess for dose responses., Results: With a median follow-up of 5.5 years, 13 patients (41%) received SRS to a recurrent or progressive nodule, 2 (6%) fractionated RT to a recurrent or progressive nodule, and 17 (53%) adjuvant fractionated RT following subtotal resection. Five-year GTC was higher with fractionated RT versus SRS (82% vs. 38%, P = 0.03). Five-year IC was also better with fractionated RT versus SRS (82% vs. 11%, P < 0.001). On univariate analysis, increasing BED 10 was significantly associated with better GTC (P = 0.039); increasing BED 3 was not (P = 0.82)., Conclusions: In this patient cohort, GTC and IC were significantly higher in patients treated with adjuvant fractionated RT compared with salvage SRS. Increasing BED 10 was associated with better GTC. Fractionated RT may provide a better therapeutic ratio than SRS for grade 2 meningiomas., (Published by Elsevier Inc.)

Purpose: The optic nerve sheath meningioma (ONSM) is one of the most challenging tumors in orbital surgery. From the perspective of mental health and patient needs, we analyzed the necessity and importance of the endoscopic transnasal approach (ETA) combined with optic nerve transection (ONT) in gross-total resection (GTR) in ONSM patients with residual vision and aim to broaden the use of ONT for specific people., Methods: The authors included patients with ONSMs who were treated between 2014 and 2022. We divided those cases into two groups named ETA group and lateral orbitotomy approach (LOA) group. We present the application of ETA and analyze the preoperative indication of the ONT and compared the advantages and disadvantages between ETA and LOA. The degree of tumor resection was based on imaging and surgical evaluation., Results: A total of 23 patients with ONSM were included. Sixteen patients underwent ETA, and seven underwent LOA. Among ETA cases, GTR was achieved in 14 patients with ONT and most patients maintained normal eye movement function (75%) and morphology (93.75%). In the ETA group, 14 patients experienced vision loss, while two other patients saw improvements in vision. And proptosis was alleviated (5.20 ± 2.34 vs 0.27 ± 0.46, p < 0.0001). Six patients with blindness and proptosis of the LOA group resulted in GTR with ONT and ophthalmectomy. Although intracranial extension and recurrence included no cases in the two groups, a significant psychological gap was presented due to cosmetic problems., Conclusions: Under the premise of reducing damage and improving aesthetics, the selection of ETA combined with ONT to gross-total resect ONSMs successfully provides a minimally invasive access with acceptable complications. As an important adjunct to GTR in the surgical treatment of ONSM, the scope of ONT application should be expanded to relieve the patient's psychological burden., (© 2024. The Author(s).)

The management of meningioma in elderly patients (MEP) presents a complex and evolving challenge. Data available offer conflicting information on treatment options and complications. This survey aimed to examine the current approach to MEP, comparing the national profile to data in the current literature. A survey addressing the treatments options and management of meningioma in elderly was designed on behalf of SINch® (Società Italiana di Neurochirurgia) and sent via email to all Chiefs of Neurosurgical Departments. The survey remained open for responses from May 5th, 2022, until November 21st, 2022. A search of the literature published between January 2000 and March 2023, in accordance to PRISMA guidelines, was included. A total of 51 Neurosurgical centers participated in the survey. The caseload profile of each center influences the choice of treatment selection (Stereotactic Radiosurgery versus open surgery) (p = 0.01) and the consolidated practice of discussing cases within a multidisciplinary group (p = 0.02). The pooled meta-analysis demonstrated a significant increased risk in the elderly group for permanent deficits (p < 0.00001), postoperative infections (p = 0.0004) and hemorrhage (p = 0.0001), perioperative mortality (p < 0.00001), and medical complications (p < 0.00001) as compared to the young population. This study presents the initial comprehensive analysis of the existing trends in the surgical management of MEP in Italy. The significant variation in practices primarily stems from the absence of standardized guidelines. While most centers have adopted an integrated approach, there is a need to promote a multidisciplinary care model. Prospective studies are needed to gather robust evidence in this clinical setting., (© 2024. The Author(s).)

BACKGROUND The BrainLab VectorVision neuronavigation system is an image-guided, frameless localization system used intraoperatively, which includes a computer workstation for viewing and analyzing operative microscopic images. This retrospective study aimed to evaluate the use of the BrainLab VectorVision infrared-based neuronavigation imaging system in 80 patients with intracranial meningioma removed surgically between 2013 and 2023. MATERIAL AND METHODS Data were retrospectively collected from 36 patients with convexity meningioma and 44 patients with parasagittal meningioma between 2013 and 2023. The surgical operation of 40 of these patients was performed with the help of neuronavigation, while the other 40 were performed without neuronavigation. Demographic data, preoperative and postoperative radiologic images, craniotomy measurements, surgical complications, and operative times of patients with and without neuronavigation were analyzed. RESULTS Using neuronavigation significantly increased surgery duration (P=0.023). In 6 patients without the use of neuronavigation, the craniotomy had to be enlarged and this resulted in superior sagittal sinus (SSS) damage (P=0.77, P=0.107). Patients for whom neuronavigation was used did not experience any sinus damage and did not require craniotomy enlargement. Postoperative epidural hematoma (EH) developed in 9 patients without navigation, whereas it developed in only 1 patient with navigation (P=0.104). Residual tumors were less common in patients using navigation (P=0.237). CONCLUSIONS The use of neuronavigation allows the incision and craniotomy to be reduced in size. Intraoperatively, it allows the surgeon to master the boundaries of the tumor and surrounding vascular structures, reducing the risk of complications. These results suggest that neuronavigation systems are an effective ancillary in meningioma surgery.

Background: Intraventricular meningioma (IVM) is a rare subtype of intracranial meningioma, accounting for 9.8 to 14% of all intraventricular tumors. Currently, there is no clear consensus on which patients with IVM should receive conservative treatment, surgery, or stereotactic radiosurgery (SRS). This research aims to analyze the outcomes, including survival and recurrence rates of patients who undergo SRS for IVM as a primary or adjuvant treatment., Methods: A systematic search was conducted in Scopus, Web of Science, PubMed, and Embase till June 5th 2023. Screening and data extraction were performed by two independent authors. Random-effect meta-analysis was performed to determine the tumor control proportion of IVM cases treated with SRS. Individual patient data (IPD) meta-analysis was performed for the progression-free survival (PFS) of the patients in the follow-up time. All analyses were performed using the R programming language., Results: Out of the overall 132 records, 14 were included in our study, of which only 7 had enough data for the meta-analysis. The tumor control proportion was 0.92 (95% CI, 0.69-0.98) in patients who underwent SRS for primary IVM. The overall tumor control in both primary and adjuvant cases was 0.87 (95% CI, 0.34-0.99). the heterogeneity was not significant in both meta-analyses (P = 0.73 and P = 0.92, respectively). Post-SRS perifocal edema occurred in 16 out of 71 cases (0.16; 95% CI, 0.03-0.56), with no significant heterogeneity (P = 0.32). IPD meta-analysis showed a PFS of 94.70% in a 2-year follow-up. Log-rank test showed better PFS in primary SRS compared to adjuvant SRS (P < 0.01)., Conclusions: According to this study, patients with IVM can achieve high rates of tumor control with a low risk of complications when treated with SRS, regardless of whether they have received prior treatment. Although SRS could be a promising first-line treatment option for asymptomatic IVM, its efficacy in symptomatic patients and its comparison with resection require further investigation., (© 2024. The Author(s).)

Trigonal meningiomas are rare intraventricular tumours that present a surgical challenge. There is no consensus on the optimal surgical approach to these lesions, though the transtemporal and transparietal approaches are most frequently employed. We aimed to examine the approach-related morbidity and surgical nuances in treating trigonal meningiomas. This retrospective review assimilated data from 64 trigonal meningiomas operated over 15 years. Details of clinicoradiological presentation, surgical approach and intraoperative impression, pathology and incidence of various postoperative deficits were recorded. In our study, Trigonal meningiomas most frequently presented with headache and visual deterioration. The median volume of tumours was 63.6cc. Thirty-one meningiomas each (48.4%) were WHO Grade 1 and WHO Grade 2, while 2 were WHO Grade 3. The most frequent approach employed was transtemporal (38 patients, 59.4%), followed by transparietal (22 patients, 34.4%). After surgery features of raised ICP and altered mental status resolved in all patients, while contralateral limb weakness resolved in 80%, aphasia in 60%, seizures in 70%, and vision loss in 46.2%. Eighteen patients (28.13%) developed transient postoperative neurological deficits, with one patient (1.5%) developing permanent morbidity. Surgery for IVMs results in rapid improvement of neurological status, though visual outcomes are poorer in patients with low vision prior to surgery, longer duration of complaints and optic atrophy. The new postoperative deficits in some patients tend to improve on follow up. Transtemporal and transparietal approaches may be employed, based on multiple factors like tumour extension, loculation of temporal horn, size of lesion with no significant difference in their safety profile., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Radiosurgery plays an important role as a treatment modality for intracranial meningiomas. Perfusion MR imaging can be performed by using arterial spin-labeling (ASL) which is a relatively new and advanced technique., Objectives: To assess the changes in perfusion parameters on ASL perfusion MRI in intracranial meningioma after radiosurgery and correlate with histopathological grade of meningioma., Materials and Methods: In this Prospective study done at the our institute over a period of 20 months (Jan 2016-Aug 2017), patients with intracranial meningiomas had perfusion MRI with ASL sequence on GE Optima 450W®, 1.5T MRI (GE Medical Systems) prior to GKT and at 6 months after GKT were included in the study., Results: Twenty-seven patients were included in this study. Mean cerebral blood flow (CBF) was higher in angiomatous meningiomas. Though mean values of average CBF, maximum, minimum, and SD derived from the ASL MR perfusion were relatively higher in post GKT group as compared to those obtained in pre-GKT but it was not clinically significant. Mean baseline volume of whole cohort was 5.71 cm3 and decreased significantly post GKT in a follow up of 6 months to 5.59 cm3 (P value 0.0018). On comparing volumes of primary and secondary group, volumes were not found be significantly decreased in primary group (P value = 0.1361), 0.1361), but significantly reduced in secondary group (7.13 vs 7.034 cm3) (P value of = 0.0038)., Conclusion: Our preliminary observations support ASL as a sensitive MRI sequence for the evaluation of meningioma perfusion patterns., (Copyright © 2024 Copyright: © 2024 Neurology India, Neurological Society of India.)

Considering that most meningiomas are pathologically benign, tumors located in the cerebellopontine angle and petroclival area should be reduced as much as possible, and radiation therapy should be administered if necessary. Consequently, relatively good preservation of cranial nerve function and local lesion control can be expected. However, because the lesions are generally located deep, and are surrounded by various important structures, performing surgical procedures is difficult, and careful management of the surgical strategy is important to avoid complications. Surgical outcomes have dramatically improved with the development of skull base and microsurgical techniques. The main surgical approaches for cerebellopontine angle meningiomas and petroclival meningiomas currently include the anterior and posterior combined transpetrosal, anterior transpetrosal, and lateral suboccipital approaches. Furthermore, with the recent developments in endoscopic surgery, minimally invasive surgery for skull base meningiomas has gradually been introduced. In this article, we explain the preoperative checkpoints, selection of the surgical approach, and surgical techniques for the resection of cerebellopontine angle meningiomas and petroclival meningiomas.

The need for resection of the meningioma capsule has long been debated and remains controversial. Even the definition of a capsule does not seem to have been established. We described the histopathological findings of the so-called capsule and the necessity for resection, considering tumor cell invasion and recurrence, based on a literature review.

Most meningiomas are benign, slow growing tumors, which rarely progress to a higher grade. The incidence rate of malignant progression is estimated to be 2.98/1000 patient-year. However, non-skull base location is a significant risk factor for progression. The median time to malignant progression is 4.3 years; however, the cumulative rate of progression approaches a plateau after 10 years. Although radiosurgery does not appear to increase the incidence rate(0.5/1000 patient-year), exact comparisons have been difficult because of differences in study populations. The median time to progression is 7.0 years from initial diagnosis and 5.0 years from radiosurgery. The cumulative rate appears to increase even after 10 years. The risk of malignant transformation after radiotherapy may increase in patients with tumor-prone syndromes, with some controversies regarding patients with neurofibromatosis type 2. Although short term follow-up in patients with meningioma suggests that radiosurgery is safe, there is uncertainty regarding its use in pediatric patients, and those with tumor-prone syndromes.

Patients with parasellar meningiomas often initially present with visual impairment. Understanding the surrounding anatomy is essential when preparing for surgery of parasellar meningiomas, as this region includes various crucial neurovascular structures. Historically, invasive craniotomy, such as the orthozygomatic approach or zygotomy, has often been attempted to access the region; however, the use of these invasive approaches has become less common, because of the accumulation of anatomical knowledge, as well as the development of surgical techniques and devices, including the endonasal endoscopic approach. Herein, we summarize how we perform surgery for parasellar meningiomas, and outline tips and pitfalls that could be useful for young residents and trainees who are new to the skull base field.

Malignant forms of meningioma, such as atypical and anaplastic meningiomas, commonly relapse. Recently, there have been many reports elucidating the molecular biological mechanisms underlying meningioma recurrence. Tumors with loss of CDKN(cyclin dependent kinase)2A and 2B or lack of the tri-methylation of lysine 27 on histone H3 protein have a particularly high recurrence rate. In general, primary treatment for recurrent meningiomas comprises stereotactic radiosurgery(SRS)or stereotactic radiotherapy(SRT). However, re-operation is recommended for SRS-, SRT-refractory tumors. One of the benefits of reoperation is that it allows tumor control while decompressing the normal tissue, and changing the tumor microenvironment. Another is that it facilitates the acquisition of pathological and molecular genetic information, which can enable clinicians to recommend precision medicine. However, during reoperation, it is often difficult to detach the tumor from the surrounding brain tissue and cranial nerves because of severe adhesion. In cases of malignant meningiomas with multiple relapses, it is important to share the purpose and goal of the surgery with the patients and their families. In other words, which is being prioritized more, a high resection rate or functional outcomes? Furthermore, salvage surgery should also be a consideration.

During surgery for meningioma, basic surgical techniques and strategies required for the removal of the tumor are common, particularly for tumors located superficially, such as convexity, parasagittal, and falx meningiomas. Four basic surgical techniques, including detachment; devascularization; debulking; and dissection should be combined and repeated in appropriate sequence, tailored to the specific conditions of each tumor. This eventually enables the total circumferential dissection of the tumor from the surrounding tissues. It is essential to retract the tumor towards the space created at the tumor center through internal debulking, rather than retracting the normal brain, to avoid damage to the surrounding brain tissue. During surgery for parasagittal meningioma with venous sinus occlusion, it is crucial to preserve the cortical veins that have developed as collateral pathways to prevent venous complications. During surgery for falx meningioma, the selection of a surgical approach including a contralateral approach based on factors such as the development of bridging veins and significant peritumoral brain edema is required. In this article, detailed surgical procedures for convexity meningioma, parasagittal meningioma, and falx meningioma were described focusing on the application of fundamental surgical techniques tailored to each tumor type.

Preoperative embolization(POE)of intracranial meningioma is performed worldwide. Although clear evidence of the effectiveness of POE has not been reported in the literature, the technique plays an important role in open surgery, especially for large or skull base meningiomas. The purposes of embolization include: 1)induction of tumor necrosis, resulting in a safer operation, 2)reduction in intraoperative bleeding, and 3)decrease in operative time. Knowledge of the functional vascular anatomy, embolic materials, and endovascular techniques is paramount to ensure safe embolization. Our standard procedure is as follows: 1)embolization is performed several days before open surgery; 2)in cases with strong peritumoral edema, steroid administration or embolization may be performed immediately prior to surgery; 3)patients undergo the procedure under local anesthesia; 4)the microcatheter is inserted as close as possible to the tumor; 5)particulate emboli are the first-line material; 6)embolization is occasionally performed with N-butyl cyanoacrylate(NBCA)glue; and 7)if possible, additional proximal feeder occlusion with coils is performed. The JR-NET study previous showed the situation regarding intracranial tumor embolization in Japan. Endovascular neurosurgeons should fully discuss the indications and strategies for POE with tumor neurosurgeons to ensure safe and effective procedures.

The jugular foramen, also known as the foramen magnum, is a highly intricate region of the skull base through which numerous critical blood vessels and nerves traverse. Meningiomas, the most common tumors in neurosurgical pathology, can arise at any location where the meninges are present, posing significant challenges. Meningiomas involving the jugular foramen and sublingual neural tube are particularly notable for their potential to extend from intracranial to extracranial sites, necessitating familiarity with extracranial anatomy, which is not typically encountered in clinical practice. A comprehensive understanding of anatomical characteristics, along with an ample field of view and working space, is crucial for handling the cerebellum, brainstem, and nerves meticulously. The use of surgical support tools such as neuromonitoring and navigation is essential for enhancing the safety of the procedure. Furthermore, preparedness for treatment options, rehabilitation, and adjunctive therapies is vital in the event of neurological symptoms such as those affecting the glossopharyngeal, vagal, or hypoglossal nerves.

The basics of meningioma surgery are represented in the '4Ds': Detachment, Devascularization, Debulking, and Dissection. When considering the 4Ds, surgical simulation using 3D images is useful, as it allows the surgeon to understand the 3D relationship between the tumor, feeding vessels, and surrounding tissues. However, the hardness of the tumor and the degree of adhesion between the tumor and surrounding tissue are difficult to determine based on 3D images, and must therefore be confirmed using MRI, such as T2-weighted images.