Gamma Knife Radiosurgery Reduce The Annual Hemorrhage Rate Of Intracranial Cavernous Malformation:Meta-analysis

Objective: This meta-analysis is to evaluate the effect of Gamma Knife Radiosurgery in reducing the annual hemorrhage rate of ICM,and to provide a reference for Gamma Knife Radiosurgery as an alternative treatment for intracranial ICM.Methods: Searching the Pub Med,Web of Science,Cochrane Library and EMBASE for the clinical studies of Gamma Knife Radiosurgery for ICM before December 2019.Search keywords: “cavernous sinus hemangioma” OR “cavernous hemangioma” OR “cavernous sinus hemangiomas” OR “cavernous angioma” OR “cavernous malformation” OR “cavernous malformations” OR “cavernoma” AND “gamma knife surgery” OR “gamma-knife” OR “gamma knife radiosurgery” OR “gamma knife.” After screening the literature,the data were extracted according to the inclusion criteria.The relevant data were processed by using the Review Manager 5.3 and Stata 12.Results: A total of 984 patients across 16 studies were included in this meta-analysis.The post-GKRS hemorrhage rate was significantly decreased compared with the pre-GKRS rate(RR,5.48;P < 0.001),and the hemorrhage rate 2 years after GKRS was significantly lower than that within 2 years after GKRS(RR,3.17;P<0.001).16 studies have shown that 70.2%(689/984)patient symptoms were improved or stationary after GKRS.Lesion volume was reduced in 48.2%(341/708)of the patients and was stationary in 49.7%(348/700)on the last follow-up images.Symptomatic adverse radiation effects(AREs)developed in 6.9%(68/984),temporary AREs was 4.9%(30/610),and permanent AREs were observed in 1.9%(11/576).In subgroup analysis,studies having mean marginal dose of ?13 Gy showed statistically significantly lower development of symptomatic AREs than those having mean marginal dose of >13Gy(4.2% vs.8.7%;P<0.001).Conclusion: Patients with intracranial cavernous malformation can benefit from GKRS owing to a reduction of annual hemorrhage rate in the first 2 years and 2 years after.GKRS using a relatively low marginal dose can be a safe and effective treatment for ICM.Further prospective studies are necessary to confirm the optimal radiation dose for ICM.