A meta-analysis of low dose (< 55 Gy) vs. high dose ( >55 Gy) adjuvant radiotherapy effects on survival for intracranial atypical meningiomas.

Background: Atypical meningiomas (AMs) can have an aggressive clinical course, exhibiting a higher recurrence rate, and portending a worse prognosis than benign meningiomas (BMs). Currently, there remains controversy as to the optimal treatment course for AMs, including the utilization of post-operative radiotherapy. Moreover, the dependence of post-operative adjuvant radiotherapy (ART) dose and its impact on survival is unclear. Objective: In this meta-analysis, we investigate the effect of lower-dose (<55 Gy) vs. higher-dose (³55 Gy) ART following surgical resection on progression free survival (PFS), overall survival (OS), and treatment toxicity complications in AM patients. Methods: In accordance with PRISMA guidelines we queried PubMed, Web of Science, Cochrane, and Scopus databases for studies reporting PFS, OS, and treatment toxicity for intracranial, primary AMs treated with higheror lower-dose ART. Results: Mean 5-year PFS for patients with AM was 73.5% for higher-dose and 70.0% for lower-dose treatments, while 5-year OS was 84.9% and 71.4%, respectively. Only one study reported 5-year OS for a low-dose ART group. ART-induced toxicity incidence for grades III or higher ranged from 0.7% to 19.6% for all AM patients. Conclusion: Our analysis demonstrates no significant difference in 5-year PFS when comparing higher- to lower-dose ART in atypical meningiomas. Importantly, lower radiotherapy dosages may reduce radiation associated complications. Future studies examining surgery + ART should be conducted to more completely elucidate the ideal radiotherapy candidate, modality, and dosage. [ABSTRACT FROM AUTHOR]