Neurosurg Focus
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WHO Grade II and III intracranial meningiomas are uncommon, but they portend a significantly worse prognosis than their benign Grade I counterparts. The mainstay of current management is resection to obtain cytoreduction and histological tissue diagnosis. The timing and benefit of postoperative fractionated external beam radiation therapy and stereotactic radiosurgery remain controversial. The authors review the stereotactic radiosurgery outcomes for Grade II and III meningiomas. ⋯ The current data for radiosurgery suggest that it has a role in the management of residual or recurrent Grade II and III meningiomas. However, better studies are needed to fully define this role. Due to the relatively low prevalence of these tumors, it is unlikely that prospective studies will be feasible. As such, well-designed retrospective analyses may improve our understanding of the effect of radiosurgery on tumor recurrence and patient survival and the incidence and impact of treatment-induced complications.
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Meningioma is the second most common type of adult intracranial neoplasm. A substantial subset of patients present with peritumoral brain edema (PTBE), which can cause significant morbidity via mass effect, complicate surgical management, and impact the safety of stereotactic radiosurgery. Recent studies suggest a close relationship between vascular endothelial growth factor-A (VEGF-A) expression and PTBE development in meningiomas. ⋯ Results of preliminary clinical studies suggest VEGF-directed therapy has modest activity against recurrent and progressive meningioma growth but can alleviate PTBE in some patients. A comprehensive understanding of the VEGF-A pathway and its modulators may hold the key to an effective therapeutic approach to treating PTBE associated with meningiomas. Further clinical trials with larger patient cohorts and longer follow-up periods are warranted to confirm the efficacy of VEGF-directed therapy.
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Tumor consistency plays an important and underrecognized role in the surgeon's ability to resect meningiomas, especially with evolving trends toward minimally invasive and keyhole surgical approaches. Aside from descriptors such as "hard" or "soft," no objective criteria exist for grading, studying, and conveying the consistency of meningiomas. ⋯ The proposed grading system provides a reliable, practical, and objective assessment of meningioma consistency and facilitates communication among providers. This system also accounts for heterogeneity in tumor consistency. With the proposed scale, meningioma consistency can be standardized as groundwork for future studies relating to surgical outcomes, predictability of consistency and vascularity using neuroimaging techniques, and effectiveness of various surgical instruments.
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The role of postoperative radiation therapy after surgery for atypical meningiomas remains controversial. In this retrospective cohort study, the authors examine the recurrence rates for atypical meningiomas after resection (with or without adjuvant radiotherapy) and identify which factors were associated with recurrence. ⋯ Adjuvant radiotherapy was effective at lowering recurrence rates in patients after STR but delivered no significant improvement in patients after GTR. Given that rates after GTR were similar with or without adjuvant radiotherapy, close observation without postoperative radiation therapy may be a viable option for these patients. Patients older than 55 years and those with mitoses noted during pathological examination had a significant risk of recurrence after GTR; for these patients, postoperative radiotherapy is recommended.