Supplementary Material for: Gamma Knife Radiosurgery for Cerebral Cavernous Malformations: Meta-analysis of Reconstructed Time-to-Event Data

Introduction: Cavernomas are vascular lesions with a genetic heritage that can be spotted on the central nervous system. Whenever these lesions are localized in eloquent regions, surgical resection is not recommended. In this type of situation, Gamma Knife stereotactic radiosurgery (GKRS) could be a feasible option for treating patients. Thus, we aim to explore the outcomes associated with this procedure. Methods: We performed a systematic review and meta-analysis of reconstructed time-to-event data based on Kaplan-Meier curves. A thorough search was conducted on PubMed, Cochrane, Web of Science and Embase databases targeting papers that provided information regarding hemorrhagic outcomes associated with GKRS through Kaplan-Meier curves. Results: After a systematic search in the specific databases, seven studies were included in this review. Notably, a total of 1071 patients had 1104 cavernomas treated by GKRS. Assessment of short-term and long-term post-procedure outcomes was performed, with the estimated overall events-free rate at 2 years being 89.8% (95% CI 87.7 – 91.5), whilst, at ten years, the estimated overall events-free rate was 71.3% (95% CI 67.2 – 75.1). Conclusion: GKRS seems to be a good alternative for control of symptomatic events in early and long-term follow-up, despite the need of further investigation provided by future studies. Keywords: cavernoma, bleeding, radiosurgery, radiotherapy, vascular.引言：脑海绵状血管畸形（cavernomas）是一类具有遗传倾向的血管性病变，可累及中枢神经系统。当此类病变位于脑功能区时，手术切除并非推荐治疗方案。在此类场景下，伽玛刀立体定向放射外科（Gamma Knife stereotactic radiosurgery, GKRS）或可成为患者的可行治疗选择。因此，本研究旨在探讨该疗法的相关临床结局。 方法：本研究针对基于Kaplan-Meier曲线重构的生存时间数据开展了系统综述与荟萃分析。我们在PubMed、Cochrane、Web of Science及Embase数据库中进行了全面检索，筛选出所有通过Kaplan-Meier曲线提供伽玛刀立体定向放射外科治疗后出血相关结局的文献。 结果：经上述数据库的系统性检索后，本综述共纳入7项研究。总计纳入1071例患者的1104处脑海绵状血管畸形接受了伽玛刀立体定向放射外科治疗。本研究对术后短期与长期结局进行了评估，结果显示，术后2年的总体无事件发生率为89.8%（95%置信区间：87.7–91.5）；术后10年的总体无事件发生率为71.3%（95%置信区间：67.2–75.1）。 结论：尽管未来仍需更多研究开展进一步验证，但伽玛刀立体定向放射外科似乎是中短期与长期随访中控制症状性事件的良好替代治疗方案。 关键词：脑海绵状血管畸形，出血，放射外科，放射治疗，血管性病变。