Postoperative radiation therapy (PORT) impact on clinical outcomes of resected atypical meningioma: A meta-analysis.

Abstract

2570 Background: Although meningiomas are among the most prevalent types of brain tumors, atypical meningiomas (AM) account for around 4% of all meningiomas. AMs tend to be more aggressive with relatively higher rates of recurrence and mortality. Gross total resection (GTR) has been the standard of care when possible. However, GTR itself is not always enough to prevent recurrence of AMs. The role of PORT remains controversial in AM as the comparative studies to support its use have provided conflicting results. The purpose of this meta-analysis is to evaluate the impact of PORT on clinical outcomes in resected AMs. Methods: A review of the medical literature was conducted using online databases. Inclusion criteria consisted of (i) AM diagnosis, (ii) English language, (iii) Simpson graded resections, and (iv) comparative studies reporting recurrence rates (RcR), Progression Free Survival (PFS), and Overall Survival (OS) with hazard ratios (HR) or Kaplan-Meier curves. A meta-analysis was conducted using an inverse variance method with random-effects model. Results: Twenty-two comparative studies with a total of 5,129 patients were included and analyzed. When GTR was attained, PORT was associated with improved RcR (HR = 0.72, 95%CI:0.59-0.86) and PFS (HR = 0.77, 95%CI:0.65-0.90), but not OS (HR = 0.93, 95%CI:0.83-1.04). When subtotal resection (STR) was attained, PORT was associated with improved PFS (HR = 0.35, 95%CI:0.26-0.48) as well as OS (HR = 0.70, 95%CI:0.54-0.89). Conclusions: This is the first meta-analysis to show that PORT is associated with PFS benefit in AMs with GTR and STR. Moreover, PORT significantly improved OS of AMs that underwent STR but had no impact on OS when GTR was achieved. In the absence of randomized clinical trials, this meta-analysis represents the most compelling data supporting the use of PORT in this patient population.