Impact of radiotherapy in atypical meningioma recurrence: literature review.

Evaluate whether radiotherapy (RT) after the neurosurgical treatment of atypical meningiomas (AM) has an impact on the reduction rate of recurrence. A Medline search through October 2017 using "atypical meningioma" returned 1277 papers for initial review. Inclusion criteria were as follows. We analyzed the database and included articles in which the anatomic pathological classification of atypical meningiomas was in accordance with WHO 2007 or WHO 2016 criteria, patients > 18 years of age, and there was postoperative external beam radiation to the tumor bed. Exclusion criteria were WHO grade I or III meningioma, patients who underwent whole-brain radiation, RT used as salvage therapy for recurrence, palliative dose of RT (< 45 Gy), recurrent AMs, and multiple AMs. Papers reporting outcomes in which atypical and anaplastic meningiomas were analyzed together were rejected, as were papers with small samples that may compromise evaluation. After filtering our initial selection, only 17 papers were selected. After reviewing the seventeen articles including a total of 1761 patients (972 female and 799 male; 1.21 female/1.0 male), the difference in proportion of tumor recurrence between patients with and without radiotherapy after neurosurgical procedure was 1.0448, 95% CI [0.8318 to 1.3125], p value = 0.7062. On the basis of this review, there is no evidence to suggest that RT decreases the rate of recurrence in patients with atypical meningiomas.