Didwania, Prabhanjan

BACKGROUND: Dural arteriovenous fistulas (dAVFs) are often treated with stereotactic radiosurgery (SRS) to achieve complete obliteration (CO), prevent future hemorrhages, and ameliorate neurological symptoms. OBJECTIVE: To summarize outcomes after SRS for dAVFs and propose relevant practice recommendations. METHODS: Using a PICOS/PRISMA/MOOSE protocol, we included patients with dAVFs treated with SRS and data for at least one of the outcomes of the study. Relevant outcomes were CO, symptom improvement and cure, and post-SRS hemorrhage or permanent neurological deficits (PNDs). Estimated outcome effect sizes were determined using weighted random-effects meta-analyses using DerSimonian and Laird methods. To assess potential relationships between patient and lesion characteristics and clinical outcomes, mixed-effects weighted regression models were used. RESULTS: Across 21 published studies, we identified 705 patients with 721 dAVFs treated with SRS. The CO rate was 68.6% (95% CI 60.7%-76.5%) with symptom improvement and cure rates of 97.2% (95% CI 93.2%-100%) and 78.8% (95% CI 69.3%-88.2%), respectively. Estimated incidences of post-SRS hemorrhage and PNDs were 1.1% (95% CI 0.6%-1.6%) and 1.3% (95% CI 0.8%-1.8%), respectively. Noncavernous sinus (NCS) dAVFs were associated with lower CO ( P = .03) and symptom cure rates ( P = .001). Higher grade was also associated with lower symptom cure rates ( P = .04), whereas previous embolization was associated with higher symptom cure rates ( P = .01). CONCLUSION: SRS for dAVFs results in CO in the majority of patients with excellent symptom improvement rates with minimal toxicity. Patients with NCS and/or higher-grade dAVFs have poorer symptom cure rates. Combined therapy with embolization and SRS is recommended when feasible for clinically aggressive dAVFs or those refractory to embolization to maximize the likelihood of symptom cure.

Abstract INTRODUCTION Optic nerve sheath meningiomas (ONSMs) are often managed with radiotherapy (RT) with the goal of achieving radiographic local control (LC) to prevent further decline in visual acuity (VA); however, reports on outcomes are limited to small retrospective series. Thus, we aimed to perform a systematic review and meta-analysis of outcomes for patients with ONSM treated with RT. METHODS A PICOS/PRISMA/MOOSE selection criteria was utilized to identify studies for inclusion. Primary outcomes were stable or improved VA and radiographic LC at last follow-up. The secondary outcome was incidence of radiation-induced retinopathy. Weighted random effects meta-analyses using the DerSimonian and Laird methods were conducted to characterize effect sizes. Mixed effects regression models were used to examine potential correlations between gross tumor volume (GTV) and outcomes. RESULTS In total, 381 patients with ONSM across 18 published studies were included. Of these, 332 and 386 treated ONSMs had information on VA or LC, respectively. Median age was 46.75 (range: 9-87), median/mean GTV was 2.905cc (range: 0.28-26.3), and median follow-up was 51.15 months (range: 1-248.4 months). The estimated LC rate at last follow-up was 100% (95% CI: 98-100%), and the estimated proportion of patients with stable or improved VA at last follow-up was 89% (95% CI: 84-93%). The rate of chronic radiation retinopathy was estimated to be 7% (95% CI: 5-11%). GTV was significantly associated with VA (p=0.014) with estimated VA rates of 96.4%, 91.4%, and 80.5% for GTVs of 2.0, 3.0, and 4.0ccs, respectively. CONCLUSIONS RT was well-tolerated in the treatment of ONSM with excellent LC achieved. Nearly 90% of patients noted either stability or improvement in VA. Larger ONSMs were found to be associated with poorer VA. Incidences of radiation-induced retinopathy were limited and estimated to be less than 10%.