Background: Meningiomas are common brain tumours that are usually defined by benign clinical course. However, some meningiomas undergo a malignant transformation and recur within a short time period regardless of their World Health Organization (WHO) grade. The current study aimed to identify potential markers that can discriminate between benign and malignant meningioma courses. Methods: We profiled the metabolites from 43 patients with low- and high-grade meningiomas. Tumour specimens were analyzed by nuclear magnetic resonance analysis; 270 metabolites were identified and clustered with the AutoPipe algorithm. Results: We observed two distinct clusters marked by alterations in glycine/serine and choline/tryptophan metabolism. Glycine/serine cluster showed significantly lower WHO grades and proliferation rates. Also progression-free survival was significantly longer in the glycine/serine cluster. Conclusion: Our findings suggest that alterations in glycine/serine metabolism are associated with lower proliferation and more recurrent tumours. Altered choline/tryptophan metabolism was associated with increases proliferation, and recurrence. Our results suggest that tumour malignancy can be reflected by metabolic alterations, which may support histological classifications to predict the clinical outcome of patients with meningiomas.

Objective: Spheno-orbital meningiomas (SOM) are rare intracranial tumors that arise at the sphenoid wing. These tumors can invade important neurovascular structures making radical resection difficult, while residual tumors often lead to recurrence. The purpose of this study was to evaluate prognostic factors influencing the recurrence and progression-free survival (PFS) rates of spheno-orbital meningiomas, with a particular focus on the role of surgery and postoperative radiotherapy. Methods: Between 2000 and March 2020, 65 cases of spheno-orbital meningioma were included, of which 50 cases underwent surgical treatment alone, and 15 cases underwent resection and radiotherapy. A Kaplan-Meier analysis was performed to provide median point estimates and PFS rates; further, Cox regression analysis was used to identify significant factors associated with treatment. Results: Gross total resection significantly reduced the risk of recurrence (p-value = 0.0062). There was no significant benefit for progression-free survival after postoperative radiotherapy (p-value = 0.42). Additionally, spheno-orbital meningiomas with an invasion of the cavernous sinus and intraconal invasion showed significantly worse PFS compared to other locations (p-value = 0.017). Conclusion: The maximal safe resection remains the most important prognostic factor associated with lower recurrence rates and longer PFS in patients with spheno-orbital meningioma. The invasion of the cavernous sinus and intraconal invasion was an independent factor associated with worse PFS. Patients with postoperative high-precision radiotherapy did not show significantly better PFS due to the small number of patients.

Objective: Medial sphenoid wing meningiomas are among the three most common intracranial meningiomas. These tumors pose a challenge to neurosurgeons in terms of surgical treatment, as they may involve critical neurovascular structures and invade the cavernous sinus. In case of the latter, a complete resection may not be achievable. The purpose of this study was to investigate prognostic features affecting recurrence and progression-free survival (PFS) of medial sphenoid wing meningiomas involving the cavernous sinus, focusing on the contribution of surgery and postoperative radiotherapy. Methods: A retrospective analysis was conducted of the database of our institution, and 105 cases of medial sphenoid wing meningioma with invasion of the cavernous sinus, which were treated between 1998 and 2019, were included. Surgical treatment only was performed in 64 cases, and surgical treatment plus postoperative radiotherapy was performed in 41 cases. Kaplan–Meier analysis was conducted to estimate median survival and PFS rates, and Cox regression analysis was applied to determine significant factors that were associated with each therapeutic modality. Results: The risk of recurrence was significantly reduced after near-total resection (NTR) (p-value = 0.0011) compared to subtotal resection. Progression-free survival was also significantly prolonged after postoperative radiotherapy (p-value = 0.0002). Conclusions: Maximal safe resection and postoperative stereotactic radiotherapy significantly reduced the recurrence rate of medial sphenoid wing meningiomas with infiltration of the cavernous sinus.

Introduction: Petroclival meningioma (PCM) remains a major neurosurgical challenge. There are still controversial strategic treatment concepts about surgical approach, the extent of resection, and postoperative radiotherapy. We aimed to evaluate prognostic factors influencing the progression-free survival (PFS) rates of PCM, with a particular focus on the retrosigmoidal approach, the role of the extent of resection, and postoperative radiotherapy.Methods: Eighty-nine patients with complete follow-up data were included. All patients were operated on via a retrosigmoidal approach, of whom 19 underwent gross total resection (GTR) and 70 underwent subtotal resection (STR). In the subgroups of tumors with infiltration of the cavernous sinus, 41 patients received near total resection (NTR) and 24 STR. Thirty-one patients received postoperative radiotherapy of the residual tumor and 58 were treated with surgery alone. Kaplan–Meier analyses and Cox regression were used to identify significant factors associated with treatment.Results: GTR (p=0.0107) and postoperative radiotherapy (p=0.014) were associated with significantly improved PFS. Even the subgroup analysis of extended PCM with infiltration of the cavernous sinus (CS) showed an advantage for PFS after near total resection (NTR) (p=0.0017). The additional radiotherapy of the residual tumor in the CS in this subgroup also showed a beneficial effect on PFS (p=0.012).Conclusion: The extension of surgical resection remains the most important prognostic factor in relation to oncological outcomes. However, the GTR of extended PCM with infiltration of the CS is associated with significant neurological morbidity and requires additional adjuvant therapy concepts. Postoperative radiotherapy is an important element in the treatment of the residual tumor after surgery.