Skull Base Meningiomas Research Articles

Stereotactic intensity-modulated radiotherapy for skull base meningioma using the HybridArc with Novalis STx system.

Skull base meningiomas are often difficult to remove completely with preserved nerve function and may require radiation therapy. However, the Gamma Knife is unsuitable for large tumor volume or the optic nerve, which is difficult to identify on imaging. We report the results of stereotactic radiotherapy with HybridArc using Novalis STx for skull base meningiomas. We retrospectively examined 28 patients with skull base meningioma who underwent stereotactic radiotherapy (54 Gy/30 fractions) with HybridArc. The 28 patients, nine males and 19 females, were aged 31-83 years (mean 58.4 years), and the tumor volume was 2.6-97.1 mL (mean 29.7 mL). HybridArc irradiation was performed with D95 54 Gy/30 fractions for all patients with a median follow-up period of 36.0 months (range: 12-78 months). Tumor control rates at 1, 2, and 5 years after radiotherapy were 92.6%, 89.1%, and 82.8%, respectively. Only one non-atypical meningioma remained uncontrolled; thus, the tumor control rate for non-atypical meningioma at 1, 2, and 5 years was 94.1%. Tumor control rates for atypical meningioma at 1, 2, and 5 years were 85.7%, 71.4%, and 53.6%, respectively, significantly worse than for non-atypical meningiomas (P = 0.0395). Radiation injury was observed in two cases (7.1%). Visual field defects were observed in 16 patients, and diplopia in 6. Visual field and diplopia improvements were achieved in 5 and 2 patients, respectively (with overlap). Stereotactic radiotherapy (54 Gy/30 fractions) with HybridArc using Novalis STx is a safe and effective approach for relatively large skull base meningiomas.

Does tumoral cavernous carotid stenosis predict an increased risk of future stroke in skull base meningiomas?

Skull base meningiomas (SBMs) involving the cavernous sinus encase the internal carotid artery (ICA) and may lead to stenosis of the vessel. Although ischemic stroke has been reported in the literature, there are to the authors' knowledge no reported studies quantifying the risk of stroke in these patients. The authors aimed to determine the frequency of arterial stenosis in patients with SBMs that encase the cavernous ICA and to estimate the risk of ischemic stroke in these patients. Records of all patients with SBM encasing the ICA whose cases were managed by the skull base multidisciplinary team at Salford Royal Hospital between 2011 and 2017 were reviewed using a two-stage approach: 1) clinical and radiological strokes were identified from electronic patient records, and 2) cases were reviewed to examine the correlation between ICA stenosis associated with SBM encasement and anatomically related stroke. Strokes that were caused by another pathology or did not occur in the perfusion territory were excluded. In the review of patient records the authors identified 118 patients with SBMs encasing the ICA. Of these, 62 SBMs caused stenosis. The median age at diagnosis was 70 (IQR 24) years, and 70% of the patients were female. The median follow-up was 97 (IQR 101) months. A total of 13 strokes were identified in these patients; however, only 1 case of stroke was associated with SBM encasement, which occurred in the perfusion territory of a patient without stenosis. Risk of acute stroke during the follow-up period for the entire cohort was 0.85%. Acute stroke in patients with ICA encasement by SBMs is rare despite the propensity of these tumors to stenose the ICA. Patients with ICA stenosis secondary to their SBM did not have a higher incidence of stroke than those with ICA encasement without stenosis. The results of this study demonstrate that prophylactic intervention to prevent stroke is not necessary in ICA stenosis secondary to SBM.

Neurological outcomes after gamma knife radiosurgery for symptomatic skull base meningiomas based on their locations: Single institution experience

Background and objectiveGross total resection of skull base meningioma is so challenging due to its relevant high morbidity. Gamma knife radiosurgery is concerned by providing a favorable therapeutic option in the management of SBM. This study aims to evaluate the neurological outcome after GKRS as an adjuvant or primary treatment for SBM according to their locations. MethodsThis retrospective cross-sectional study consisted of 108 patients with SBM who underwent GKRS as an adjuvant or primary treatment. We found 40 patients with cavernous sinus meningioma (CSM), 36 patients with petroclival meningioma (PCM), and 22 patients with cerebellopontine angle meningioma (CPM). 81.1% of whom were female (n = 90) with a median age of 52.68 years. The mean tumor volume was 4.5 cm3 and the mean marginal dose was 13 Gy. ResultsTumor control was achieved in 96.4 % of patients at a median follow-up of 38.4 months. Over all 17 of 108 patients (15.6%) report improvement in their neurological symptoms. Patients with CPM demonstrated lower rates of neurological symptoms improvement compared to patients with PCM and CSM. Deterioration of neurological symptoms after GKRS developed in 11 patients (10.1%) which was more reported by patients with CSM than the others. The most improvement in cranial nerve deficit was in CN Ⅵ, Ⅴ, VIII among patients with CSM, PCM, and CPM respectively. ConclusionGKRS is acceptable as a primary or adjuvant treatment for SBM by providing an appreciable rate of improvement in neurological symptoms.

NCMP-17. IMPROVEMENT IN CRANIAL NEUROPATHIES FOLLOWING STEREOTACTIC RADIOTHERAPY ALONE FOR SKULL BASE MENINGIOMAS

Abstract Cranial neuropathies are a common presenting symptom in skull base meningiomas. Many of these tumors are not amenable to surgical resection; for these patients, stereotactic radiotherapy (SRT) is a viable option. Our study sought to investigate the efficacy of SRT for improving cranial neuropathies and identify predictors that portend favorable response. A single-institution retrospective analysis was performed for patients with skull base meningiomas causing cranial neuropathies who received SRT as sole treatment from 2001 to 2021. Clinical variables were collected and analyzed for predictors of improvement. Subgroup analysis for each type of cranial neuropathy was also performed. Overall 101 patients were included, of which 51 (50.4%) had an improvement in cranial neuropathy following SRT. There was no difference in gender or age between patients with and without improvement. The most common tumor location was cerebellopontine angle (n=38), followed by cavernous sinus (n=27) and optic canal (n=25). Cranial nerve II was most frequently affected (n=34), followed by VI (n=28) and V (n=27). There was no significant difference in tumor volume, radiation dose, location, or specific cranial nerve affected between patients with and without improvement. Median time to improvement was 8 months (IQR 3-15). In subgroup analysis, patients with optic neuropathy who experienced improvement after SRT were significantly younger (50.7 vs. 60.1 years, p=0.03), while patients with trigeminal neuropathy who experienced improvement were significantly older (69.6 vs. 58.7 years, p=0.03). For patients with extraocular movement neuropathies or vestibulocochlear dysfunction, there were no significant factors associated with improvement. Half of patients with cranial neuropathy from skull base meningiomas experience symptomatic improvement following sole SRT. Age may play a role in predicting improvement, with younger patients more likely to have improved vision and older patients more likely to experience improvement in trigeminal neuropathy.

SURG-42. FACTORS INFLUENCING TUMOR RECURRENCE AFTER RESECTION OF SKULL-BASE MENINGIOMAS

Abstract BACKGROUND Resection of skull-base meningiomas is challenging, given the proximity of and adherence to neurovascular structures. We characterize the benefits of neurosurgical resection of meningiomas, comparing clinical and surgical outcomes based upon tumor location within and outside the skull base. METHODS Data were retrospectively collected from 85 patients who underwent surgical resection of meningioma between 2008 – 2018, for whom long-term follow-up was available. Outcomes were compared between locations: non-skull base, anterior fossa, middle fossa, and posterior fossa. Logistic regression analysis was used to analyze pre-operative and pathologic factors influencing recurrence. RESULTS Forty-five (54.1%) tumors were located on the skull base: 29 anterior fossa, 22 middle, and 6 posterior. Simpson grade 1 or 2 resection was achieved in 63 patients. Mean Ki-67 showed a statically significant difference between all tumor locations: non-skull base (7.1), anterior fossa (4.0), middle fossa (10.8), posterior fossa (2.8) (p = 0.009). Simpson grade differed significantly by tumor location with percentage of Simpson grade 1 resections as follows: non-skull base supratentorial (45.7%), non-skull base infratentorial (0.0%), anterior (71.5%), middle (30.0%), posterior (16.7%) (p = 0.022). Tumors recurred in 11 patients with recurrence differing significantly between locations: non-skull base (18.2%), anterior (3.8%), middle (36.4%), posterior (0.0%) (p = 0.046). Median progression-free survival was 115.5 months and did not significantly differ by location. Larger tumor volumes (p = 0.018), Simpson grade 3 resection (p = 0.016), and increased Ki67 (p = 0.046) were associated with higher recurrence risk. No variables predicted post-operative neurological deficits. CONCLUSIONS High variability exists within skull-base meningiomas, depending on the cranial fossa of origin. Location may impact the molecular make-up, extent of resection, and patient outcomes. Due to the high-risk anatomy of the skull base, confirming these predictors of recurrence is vital to optimize initial treatment and decrease the risk associated with salvage treatment.

MENINGIOMA-05 ONE HUNDRED SKULL BASE MENINGIOMAS OPERATED AT BLACK LION SPECIALIZED HOSPITAL, ADDISABABA, ETHIOPIA

Abstract INTRODUCTION Since the start of the neurosurgery training program in Ethiopia, the specialty has significantly grown both in terms of service provision and quality of surgeries. Locally trained neurosurgeons are now able to operate on complex skull base tumors. Our study used a retrospective design of an in-hospital series of skull base meningiomas with short-term follow-up. METHODS A total of 100 patients (mean age, 40.2 years;80% women) had undergone surgery for skull base meningiomas from 2016 to 2017. Their symptoms included headache in 90%, impairment of vision in 47%, gait impairment in 25%, cognitive dysfunction in 29%, and seizures in 18%. Of the 100 tumors, 44% had a diameter >50 mm. Microsurgery was performed using the Hudson drill, Gigli saw, and conventional microsurgical instruments. RESULTS A total of 59 complications in 39 patients occurred. Eleven patients had died within 3 months postoperatively. The cranial infection rate was 14%. The rate of Simpson grade I and II was 63%. We present the 3 -12 month outcomes for 84 of the 100 patients. Of the 16 remaining patients, 4 were lost to follow-up (mean, 6.7 months) and 12 had died. Headache was noted in 65 of 74 patients preoperatively and in 20 during follow-up. Overall,33 patients reported better vision, 48 reported similar vision, and 3 patients reported worse vision. Finally, 20 patients had gait difficulties preoperatively and 9 reported impaired gait during follow-up. CONCLUSION A young faculty of locally trained neurosurgeons in a low income country, Ethiopia, were able to do large skull base meningiomas. The patients had presented at a young age with severe disabilities due to advanced disease. Surgery led to symptom improvement in a large proportion of patients. The outcome of patients was promising; however, there should still be improvement on the resource limitations faced.

Health-Related Quality of Life Outcomes in Meningioma Patients Based upon Tumor Location and Treatment Modality: A Systematic Review and Meta-Analysis.

Patients with meningiomas may have reduced health-related quality of life (HRQoL) due to postoperative neurological deficits, cognitive dysfunction, and psychosocial burden. Although advances in surgery and radiotherapy have improved progression-free survival rates, there is limited evidence regarding treatment outcomes on HRQoL. This review examines HRQoL outcomes based on tumor location and treatment modality. A systematic search in PubMed yielded 28 studies with 3167 patients. The mean age was 54.27 years and most patients were female (70.8%). Approximately 78% of meningiomas were located in the skull base (10.8% anterior, 23.3% middle, and 39.7% posterior fossae). Treatment modalities included craniotomy (73.6%), radiotherapy (11.4%), and endoscopic endonasal approach (EEA) (4.0%). The Karnofsky Performance Scale (KPS) was the most commonly utilized HRQoL instrument (27%). Preoperative KPS scores > 80 were associated with increased occurrence of postoperative neurological deficits. A significant difference was found between pre- and post-operative KPS scores for anterior/middle skull base meningiomas (SBMs) in comparison to posterior (SBMs) when treated with craniotomy. Post-craniotomy SF-36 scores were lower for posterior SBMs in comparison to those in the anterior and middle fossae. Risk factors for poor neurological outcomes include a high preoperative KPS score and patients with posterior SBMs may experience a greater burden in HRQoL.

The usefulness of [68Ga]Ga-DOTA-JR11 PET/CT in patients with meningioma: comparison with MRI.

Clinical studies of PET imaging using SSTR2 agonists have demonstrated high accuracy and correlation with SSTR2 expression in meningiomas. However, the usefulness of the SSTR2 antagonist with [68Ga]Ga-DOTA-JR11 is uncertain. To evaluate the diagnostic performance of [68Ga]Ga-DOTA-JR11 PET/CT and to clarify tumor characteristics in patients with suspected meningiomas. Patients with suspected de novo or recurrent meningioma in complex locations or atypical images were enrolled from August 2021 to October 2022 in prospective study. All patients underwent contrast-enhanced MRI (CE-MRI), [68Ga]Ga-DOTA-JR11 PET/CT, and histopathological evaluation. Tumor uptake of [68Ga]Ga-DOTA-JR11 was measured by SUVmax and tumor-endocranium ratio (TBR). Diagnostic performance was compared between PET and MRI. Of 36 (50.0 ± 13.0years of age, 20 women) patients, 32 were histopathologically confirmed meningiomas and four with other tumors. [68Ga]Ga-DOTA-JR11 uptake was significantly higher in meningioma patients than in those with other tumors (SUVmax: 13.6 ± 7.7 vs. 5.2 ± 3.0, P < 0.001; TBR: 64.2 ± 27.7 vs. 25.0 ± 18.9, P = 0.001). [68Ga]Ga-DOTA-JR11 PET/CT detected 31 meningiomas, while CE-MRI detected 17 meningiomas of 25 initial diagnosis and 11 recurrent tumors; [68Ga]Ga-DOTA-JR11 PET had an incremental diagnostic value of 24% (6/25) over MRI in the group of initial diagnosis. There was no statistically significant difference in diagnostic efficacy between PET and MRI (P = 0.45) for all 36 patients. In skull base meningiomas, PET provided a more definitive diagnosis of pituitary involvement (in 12, not in12), compared to MRI (in eight, possible in six, possible not in six, not in four). PET revealed bone involvement in all 14 patients proven by pathology, while MRI identified only 11. [68Ga]Ga-DOTA-JR11 PET/CT provided high image quality and presented an ideal diagnostic performance in detecting meningioma and evaluating the involvement of the pituitary and bone. The study provides valuable evidence for the use of [68Ga]Ga-DOTA-JR11 PET/CT as a complementary imaging modality to CE-MRI in the evaluation of meningiomas.

P18.01.A A MORPHOMETRIC ANALYSIS OF 40 DRY ASIAN SKULLS TO INVESTIGATE ANATOMICAL VARIABILITY IN THE SUPRASELLAR REGION AND ITS IMPLICATIONS IN MENINGIOMA SURGERY

Abstract INTRODUCTION Meningiomas are the most common type of primary brain tumour and when symptomatic, are usually treated by surgical resection. Removing skull-base meningiomas is challenging and subtotal resection remains common, despite utilising the latest surgical METHODS . In the suprasellar region, surgery is particularly high risk and carries a 10-20% rate of postoperative visual impairment. This morphometric analysis of 40 dry skulls furthers our understanding of anatomical variability of 3 structures in the suprasellar region: the limbus sphenoidale (LS), prechiasmatic sulcus (PS) and optic strut (OS). Understanding suprasellar anatomical variability is vital for neurosurgeons operating within the region to reduce complication rates and in achieving gross total resection. METHODS Variants of the LS (A, B and C) are defined according to descriptions used from a previous study. Curved and straight lengths of the LS are measured using metal callipers and string. Between the three variants, statistical analysis is used to compare differences in lengths, and the ratio between their curved and straight length. PS angle, length and width are measured according to previous studies’ definitions. OS position is determined by measuring its distance from the LS and a drawn midline. Skulls are grouped using PS variables and OS position according to adapted classification systems used in previous studies. RESULTS Variants A, B and C of the LS exhibited incidences of 33.33%, 52.82% and 15.39%, respectively. Limbus ratio was significantly different (p&amp;lt;0.05) between variants. Average sulcal angle was 32 ± 13.3°, whilst sulcal type ranked in prevalence: narrow flat sulci (34.21%)&amp;gt; very narrow steep (28.95%)&amp;gt; very narrow flat (21.05%) &amp;gt; narrow steep (15.79%). 32.50% and 18.42% of struts exhibited notable differences in their distances from the midline and from the LS, respectively. CONCLUSION The present study improves our understanding of the prevalence of anatomical variants within the suprasellar region and has implications for meningioma surgery. The type C variant is an overhanging ridge, underneath which meningiomas could be hidden from a surgeon’s view during transcranial procedures. Only two studies have previously documented the type C variant, whose incidence in the present study (15.39%) is within the boundaries of previous research; patients with this variant might require removal of the landmark during surgery to achieve gross total resection. The PS displayed varying degrees of steepness, and skulls were on average steeper than previously documented populations. A considerable proportion of skulls exhibited notable differences in left and right OS position. Establishing PS morphology and OS position preoperatively might be helpful in reducing the risk of visual impairment in future operations through better understanding the course of the optic nerve.

Long-term Experience of LINAC Single-Dose Radiosurgery for Skull Base Meningiomas: A Retrospective Single-Center Study of 241 Cases.

Stereotactic radiosurgery (SRS) is increasingly applied to treat meningiomas, attributable to their increased incidence in older individuals at greater surgical risk. To evaluate the effectiveness of treatment with linear accelerator (LINAC)-based stereotactic radiosurgery in skull base meningiomas as either primary treatment or postresection adjuvant therapy. This study included 241 patients diagnosed with skull base meningiomas treated by single-dose SRS, with a median age of 59 years. SRS was primary treatment in 68.1% (n = 164) and adjuvant treatment in 31.9% (n = 77), using LINAC (Varian 600, 6 MeV). The median tumor volume was 3.2 cm 3 , and the median coverage dose was 14 Gy. Bivariate and multivariate analyses were performed to determine predictive factors for tumor progression, clinical deterioration, and complications. Kaplan-Meier analysis was used for survival analysis. After the median follow-up of 102 months, the tumor control rate was 91.2% (n = 220). Progression-free survival rates were 97.07%, 90.1%, and 85.7% at 5, 10, and 14 years, respectively. Clinical improvement was observed in 56 patients (23.2%). In multivariate analysis, previous surgery (hazard ratio 3.8 [95%CI 1.136-12.71], P = .030) and selectivity (hazard ratio .21 [95%CI 0.066-0.677], P = .009) were associated with tumor progression and increased maximum dose (odds ratio [OR] 4.19 [95% CI 1.287-13.653], P = .017) with clinical deterioration. The permanent adverse radiation effect rate was 6.2% (n = 15) and associated with maximum brainstem dose >12.5 Gy (OR 3.36 [95% CI .866-13.03], P = .08) and cerebellopontine angle localization (OR 3.93 [95% CI 1.29-11.98], P = .016). Treatment of skull base meningiomas with single-dose SRS using LINAC is effective over the long term. Superior tumor control is obtained in patients without previous surgery. Adverse effects are related to localization in the cerebellopontine angle, and maximum brainstem radiation dose was >12.5 Gy.

Impact of salvage surgery with or without reirradiation for skull base meningiomas recurring after prior radiotherapy.

Long-term follow-up of meningiomas has demonstrated recurrence rates ranging from 2.5% to 48% after 10 years, depending on histology grade. There are limited data available to guide the management of recurrent and previously irradiated skull base meningiomas, and challenges related to salvage surgery, reirradiation, and lack of clear systemic therapy strategies remain. In this study, the authors analyzed data from their experience with recurrent and previously irradiated meningiomas to assess the impact of salvage surgery and reirradiation on progression-free survival (PFS). A retrospective cohort study of 48 patients with recurrent and previously irradiated meningiomas who were treated between 1995 and 2021 was conducted. Data were extracted from medical records and included clinical, radiological, and pathologic reports. Patients were clustered according to WHO grades. The authors analyzed the complications related to reirradiation and salvage surgery and the impact of different treatment modalities on PFS using Cox proportional hazard ratios. Forty-eight patients (33 with WHO grade I, 11 with WHO grade II, and 4 with WHO grade III meningiomas) were treated for 143 recurrences after their first radiation treatment. For WHO grade I meningiomas, there was no change in tumor control rates with adjuvant repeat radiotherapy (HR 0.784, 95% CI 0.349-1.759; p = 0.55), and in terms of extent of resection (EOR), subtotal resection (STR) alone was associated with an increased risk of recurrence when compared with gross-total resection (GTR) (HR 3.38, 95% CI 1.268-9.036; p = 0.0189). For WHO grade II meningiomas, GTR did not significantly confer improved tumor control relative to STR (HR 0.42, 95% CI 0.17-1.037; p = 0.055), but adjuvant repeat radiotherapy after STR was associated with improved outcomes (HR 0.316, 95% CI 0.13-0.768; p = 0.0029). Finally, for WHO grade III meningiomas, EOR did not correlate with outcomes (HR 0.75, 95% CI 0.22-2.482; p = 0.588), but repeat radiotherapy alone was associated with a decreased odds of progression (HR 0.276, 95% CI 0.078-0.97; p = 0.0028). This study examined the impact of retreatment on PFS in a large cohort of patients with recurrent meningiomas that had been previously irradiated. At the time of recurrence, WHO grade I meningiomas exhibited improved PFS with GTR, subtotally resected WHO grade II meningiomas appeared to have improved PFS when reirradiated, and reirradiation in WHO grade III meningiomas showed improved PFS.

Interdisciplinary Therapeutic Approaches to Atypical and Malignant Meningiomas.

Meningiomas have the highest incidence among brain tumors. In contrast to benign tumors that constitute the majority of this tumor entity, the treatment of aggressive meningiomas (WHO Grade 2 and 3) is more challenging, requiring gross total removal of the tumor and the affected dura and adjuvant radiotherapy. Sometimes the location and/or the configuration of the tumor do not favor radical surgical resection without endangering the patient's clinical condition after surgery and pharmacological therapy has, until now, not been proven to be a reliable alternative. Discussion: In this narrative review, we discuss the current literature with respect to the management of meningiomas, discussing the importance of the grade of resection in the overall prognosis of the patient and in the planning of adjuvant therapy. Conclusions: According to the location and size of the tumor, radical resection should be taken into consideration. In patients with aggressive meningiomas, adjuvant radiotherapy should be performed after surgery. In cases of skull base meningiomas, a maximal, though safe, resection should take place before adjuvant therapy. An interdisciplinary approach is beneficial for patients with primary or recurrent meningioma.

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

Intracranial meningiomas are a diverse group of tumors, which vary by grade, genetic composition, location, and vasculature. Expanding the understanding of the supply of skull base (SBMs) and non-skull base meningiomas (NSBMs) will serve to further inform resection strategies. We sought to delineate the vascular supply of a series of intracranial meningiomas by tumor location. A retrospective study of intracranial meningiomas that were studied using preoperative digital subtraction angiograms before surgical resection at a tertiary referral center was performed. Patient, tumor, radiologic, and treatment data were collected, and regression models were developed. One hundred sixty-five patients met inclusion criteria. The mean age was 57.1 years (SD: 12.6). The mean tumor diameter was 4.9 cm (SD: 1.5). One hundred twenty-six were World Health Organization Grade I, 37 Grade II, and 2 Grade III. Arterial feeders were tabulated by Al-Mefty's anatomic designations. SBMs were more likely to derive arterial supply from the anterior circulation, whereas NSBMs were supplied by external carotid branches. NSBMs were larger (5.61 cm vs 4.45 cm, P = <.001), were more often presented with seizure (20% vs 8%, P = .03), were higher grade ( P = <.001) had more frequent peritumoral brain edema (84.6% vs 66%, P = .04), and had more bilateral feeders (47.7% vs 28%, P = .01) compared with SBMs. More arterial feeders were significantly associated with lower tumor grade ( P = .023, OR = 0.59). Higher tumor grade (Grade II/III) was associated with fewer arterial feeders ( P = .017, RR = 0.74). Meningioma location is associated with specific vascular supply patterns, grade, and patient outcomes. This information suggests that grade I tumors, especially larger tumors, are more likely to have diverse vascular supply patterns, including internal carotid branches. This study may inform preoperative embolization and surgical considerations, particularly for large skull base tumors.

Significance of Early Postoperative Magnetic Resonance Imaging following Intracranial Meningioma Resection.

The significance of early postoperative magnetic resonance imaging (MRI) for meningioma resection has not yet been evaluated. We retrospectively reviewed patients with intracranial meningiomas resected at our institute between 2011 and 2021. Early postoperative MRI with contrast enhancement was routinely performed within 48 h after surgery while first follow-up MRI was performed approximately after 6 months. MRI findings were reviewed, and the risk factors for postoperative infarction and early recurrence were analyzed. Among the 245 resections performed, early postoperative MRI was performed in 200 cases. Postoperative radiological and symptomatic infarctions occurred in 54 (27%) and 17 patients (9%), respectively. Diameter > 5 cm (p = 0.015) and skull base location (p = 0.010) were independent risk factors for radiological infarctions. Follow-up postoperative MRI performed in 180 patients (90%) detected early recurrence in 24 patients (13%). Non-gross total resection was an independent risk factor for early recurrence (p < 0.0001). Additionally, early recurrence after gross total resection occurred significantly more frequently in meningiomas with dural sinus involvement than in those without (8.3% vs. 0%, p = 0.018). Thus, early postoperative MRI may enable the timely assessment of postoperative neurological deficits, especially after large skull base meningioma resections along with accurate detection of early recurrence, which is critical for meningiomas with dural sinus involvement.

Benefits of combined use of 68−Ga Dotatoc and 5-ALA fluorescence for recurrent atypical skull-base meningioma after previous microsurgery and Gamma Knife radiosurgery: a case report

BackgroundStudies of novel microsurgical adjuncts, such as 5-aminolevulinic acid (5-ALA) fluorescence have shown various fluorescence patterns within meningiomas, opening new avenues for complete microsurgical resection. Here, we present a recurrent, radiation-induced meningioma, previously operated on two occasions (initial gross total resection and subtotal 12 years later) and also irradiated by Gamma Knife radiosurgery (GKR, 6 years after the first surgery). We thought to assess the usefulness of 68−Ga Dotatoc in surgical target planning and of 5-ALA as an adjunct for maximal microsurgical excision.Case reportWe report on a 43 years-old Caucasian male diagnosed with atypical, radiation induced WHO II meningioma, with left basal temporal bone implantation. Hodgkin lymphoma treated with cranial and mediastinal radiation during infancy marked his personal history. He underwent a first gross total microsurgical resection, followed 6 and 12 years later by Gamma Knife radiosurgery (GKR) and second subtotal microsurgical resection, respectively. Magnetic resonance imaging (MRI) displayed new recurrence 13 years after initial diagnosis. He was clinically asymptomatic but routine Magnetic resonance imaging showed constant progression. There was strong 68−Ga Dotatoc uptake. We used 5-ALA guided microsurgical resection. Intraoperative views confirmed strong fluorescence, in concordance with both preoperative Magnetic resonance imaging enhancement and 68−Ga Dotatoc. The tumor was completely removed, with meningeal and bone resection.ConclusionThe authors conclude that fluorescence-guided resection using 5-ALA is useful for recurrent atypical, radiation-induced meningioma even despite previous irradiation and multiple recurrences.

Factors Influencing the Degree of Resection and Proposed Preoperative Scale for The Management of Skull Base Meningiomas

Objectives: to identify factors involved in the degree of resection of skull base meningiomas and to propose a scale to calculate the probability of total resection. Materials and methods: unicenter, observational, retrospective study of patients operated on in the period 06/2018 – 06/2022. The following variables were used: age, clinic, location, size, previous embolization, perilesional edema, intertumoral calcium, characteristics in T2 and T1 and bone invasion. The degree of resection was measured with the traditional Simpson classification and was also divided into total (Simpson I, II and III) and subtotal (Simpson IV and V) resection. With the results, a scale was proposed taking into account the variables with statistical significance (p &lt; 0.05). A literature review of the topic was conducted. Results: A total of 23 patients were operated. They were statistically significant associated with Simpson's grade, location (p 0.002) and size (p 0.001). Associated with total and subtotal resection, bone invasion (p 0.013). For the scale we use: location (anterior 1 point, posterior 2 points, medial 2 points and medial involving cavernous sinus 3 points), size (&lt;5 cm 1 point, &gt;5 cm 2 points) and bone invasion (not 1 point and if 2 points). We performed an inferential analysis and an association was observed between the scale performed and the degree of resection (p 0.005). Conclusion: In our study, an association was observed between bone size, location and invasion with the degree of resection achieved. We proposed a scale to measure the probability of total resection.

Long-Term Outcomes of Stereotactic Radiosurgery for Postoperative World Health Organization Grade I Skull Base Meningioma: Utility of Ki-67 Labeling Index as a Prognostic Indicator.

Gross total resection, without causing neurological deficits, is challenging in skull base meningioma (SBM). Therefore, stereotactic radiosurgery (SRS) is an important approach for SBMs; however, it is difficult to predict the long-term prognosis. To identify the predictive factors for tumor progression after SRS for World Health Organization (WHO) grade I SBMs, focusing on the Ki-67 labeling index (LI). In this single-center retrospective study, factors affecting progression-free survival rates (PFSs) and neurological outcomes in patients undergoing SRS for postoperative SBMs were evaluated. Based on the Ki-67 LI, patients were classified into 3 groups: low (<4%), intermediate (4%-6%), and high LI (>6%). In the 112 patients enrolled, the cumulative 5- and 10-year PFSs were 93% and 83%, respectively. The PFSs were significantly higher in the low LI group (95% at 10 years) compared with the other groups (intermediate LI, 60% at 10 years, P = .007; high LI, 20% at 10 years, P = .001). Multivariable Cox proportional hazard analysis demonstrated that the Ki-67 LI was significantly associated with the PFSs (low vs intermediate LI; hazard ratio, 6.00; 95% CI, 1.41-25.54; P = .015; low vs high LI; hazard ratio, 31.90; 95% CI, 5.59-181.77; P = .001). Ki-67 LI may be a useful predictor of long-term prognosis in SRS for postoperative WHO grade I SBM. SRS provides excellent long- and mid-term PFSs in SBMs with Ki-67 LIs <4% or 4% to 6%, with a low risk of radiation-induced adverse events.

Different clinical and cytogenetic features of primary skull base meningiomas and non-skull base meningiomas

To investigate the different clinical and cytogenetic features of skull base meningiomas (SBMs) and non-SBMs (NSBMs). We conducted a retrospective study on a series of 316 patients with primary intracranial meningiomas. The t-test and the Chi-square test were used to analyze the differences between 194 SBMs and 122 NSBMs. The Cox analysis was used to determine prognostic factors for tumor recurrence. Compared with NSBMs, on average, the age of patients with SBMs was about 2.88 years younger (p = 0.024); the duration of operation of SBMs was 2.73h longer (p < 0.001); the duration of hospital stays of patients with SBMs was about 6.76 days longer (p < 0.001); the tumor volume was 7.69 cm3 smaller (p = 0.025); the intraoperative blood loss was 147.61ml more (p = 0.039); the total cost of SBMs was 1.39 times more (p < 0.001); the preoperative KPS, postoperative KPS, and follow-up KPS of patients with SBMs were all respectively lower (p < 0.001); Gross total resection was less achieved (p < 0.001). SBMs (average of 20.80 per sample) had a smaller total number of copy number variations (CNVs) than NSBMs (29.98 per sample) (p = 0.009). Extremely large CNVs (> 5Mb) were more likely to present in NSBMs (p < 0.001). Cox analysis showed that subtotal resection (p = 0.002) and the total number of CNVs (p = 0.015) were independent risk factors for tumor recurrence. The clinical and cytogenetic features of SBMs were different from NSBMs. Moreover, the degree of resection and the total number of whole-genome CNVs were independent prognostic factors for tumor recurrence.

Pterional Approach for Anterior Skull Base Midline Meningiomas against "The More The Merrier" Approach: An Institutional Experience.

Objective Anterior midline skull base meningiomas involving olfactory groove, planum sphenoidale, and tuberculum sellae were usually managed with bifrontal craniotomy until the dawn of advanced microsurgical techniques. With the emergence of microsurgical techniques, midline meningiomas could be tackled solely from a unilateral pterional approach. We present our experience with pterional approach in managing anterior skull base midline meningiomas, including the technical nuances and outcomes. Methods Fifty-nine patients who underwent excision of anterior skull base midline meningiomas through a unilateral pterional craniotomy between 2015 and 2021 were retrospectively analyzed. The surgical technique and patient outcomes in the context of visual, behavioral, olfaction, and quality of life were evaluated during the follow-up. Results A total of 59 consecutive patients were assessed over an average follow-up period of 26.6 months. Twenty-one (35.5%) patients had planum sphenoidale meningioma. Olfactory groove and tuberculum sellae meningioma groups consist of 19 (32%) patients each. Visual disturbance was the predominant symptom with almost 68% of patients presented with it. A total of 55 (93%) patients had complete excision of the tumor with 40 patients (68%) achieving Simpson grade II excision, and 11 (19%) patients had Simpson grade I excision. Among operated cases, 24 patients (40%) had postoperative edema among which 3 (5%) patients had irritability and 1 patient had diffuse edema requiring postoperative ventilation. Only 15 (24.6%) patients had contusion of the frontal lobe and were managed conservatively. Five patients (50%) with seizures had an association with contusion. Sixty-seven percent of patients had improvements in vision and 15% of patients had a stable vision. Only eight (13%) patients had postoperative focal deficits. Ten percent of patients had new-onset anosmia. The average Karnofsky score was improved. Only two patients had recurrence during follow-up. Conclusion A unilateral pterional craniotomy is a versatile approach for the excision of anterior midline skull base meningioma, even for the larger lesions. The ability of this approach in the visualization of posterior neurovascular structures at the earlier stages of surgery while avoiding the opposite frontal lobe retraction and frontal sinus opening makes this approach more preferable over the other approaches.

Role of risk factors, scoring systems, and prognostic models in predicting the functional outcome in meningioma surgery: multicentric study of 552 skull base meningiomas

Despite the importance of functional outcome, only a few scoring systems exist to predict neurologic outcome in meningioma surgery. Therefore, our study aims to identify preoperative risk factors and develop the receiver operating characteristics (ROC) models estimating the risk of a new postoperative neurologic deficit and a decrease in Karnofsky performance status (KPS). A multicentric study was conducted in a cohort of 552 consecutive patients with skull base meningiomas who underwent surgical resection from 2014 to 2019. Data were gathered from clinical, surgical, and pathology records as well as radiological diagnostics. The preoperative predictive factors of functional outcome (neurologic deficit, decrease in KPS) were analyzed in univariate and multivariate stepwise selection analyses. Permanent neurologic deficits were present in 73 (13.2%) patients and a postoperative decrease in KPS in 84 (15.2%). Surgery-related mortality was 1.3%. A ROC model was developed to estimate the probability of a new neurologic deficit (area 0.74; SE 0.0284; 95% Wald confidence limits (0.69; 0.80)) based on meningioma location and diameter. Consequently, a ROC model was developed to predict the probability of a postoperative decrease in KPS (area 0.80; SE 0.0289; 95% Wald confidence limits (0.74; 0.85)) based on the patient’s age, meningioma location, diameter, presence of hyperostosis, and dural tail. To ensure an evidence-based therapeutic approach, treatment should be founded on known risk factors, scoring systems, and predictive models. We propose ROC models predicting the functional outcome of skull base meningioma resection based on the age of the patient, meningioma size, and location and the presence of hyperostosis and dural tail.