Adjuvant Radiosurgery Versus Serial Surveillance Following Subtotal Resection of Atypical Meningioma: A Systematic Analysis

BACKGROUND:Atypical meningioma (AM) is an aggressive subtype of meningioma associated with a high recurrence rates (RR) following surgical resection. Recent studies have compared outcomes of various treatment strategies, but advantages of adjuvant radiosurgery (ARS) over serial surveillance (SS) following subtotal resection (STR) remain unclear. To further elucidate this issue, we systematically analyzed the current literature on AM and compared outcomes of ARS versus SS after STR. METHODS:Embase, PubMed, and Cochrane databases were queried using relevant search terms. Retrospective case series that described patients with AM treated with ARS and SS after STR were included. Tests of proportions were performed to detect significant variations in RR, 5-year progression-free survival (PFS), and 5-year overall survival (OS) between the treatment strategies (ARS vs. SS) and among individual studies. RESULTS:A total of 619 patients (263 in the ARS group and 356 in the SS group) were identified. Mean RR, 5-year PFS, and 5-year OS were 53.5%, 50.3%, and 74.9%, respectively, for ARS versus 89.8%, 19.1%, and 89.8% for SS. RR differed between treatment strategies and ARS studies (P < 0.001), and 5-year PFS differed among treatment strategies, ARS, and SS studies (P < 0.001, P = 0.007, and P < 0.001, respectively). CONCLUSIONS:The data presented here show significant differences in RR and 5-year PFS between ARS and SS, suggesting a potential benefit of ARS. As our understanding of the clinical outcomes of various treatment strategies for AM increases, we also move closer to integrating modalities, such as radiosurgery, into management guidelines.