Introduction: The goal was to define the long-term benefits and risks of stereotactic radiosurgery (SRS) for patients with arteriovenous malformations (AVMs) who underwent prior embolization.
Methods: Between 1999 and 2013, the authors performed CyberKnife radiosurgery on 111 patients with brain AVMs; 57 patients had embolization of their AVMs prior to CyberKnife treatment. Among those who underwent prior embolization, 22 (42%) had at least one prior hemorrhage and 12 (21%) had undergone prior surgical resection. The median Spetzler-Martin grade was three, with a median target volume of 4cm(3) treated with a median target dose of 20Gy.
Results: Among the 57 patients who underwent CyberKnife radiosurgery after embolization, 43 (75%) had clinical and radiographic follow-up. The median follow-up time was 35 months. Only two patients had a post-radiosurgery hemorrhages, at 11 and 17 months following treatment. At the time of last follow-up, sixteen patients (37%) had stable AVMs, 22 (51%) had partial obliteration and 5 (12%) had complete obliteration. In the univariate and multivariate analyses, prior embolization was not associated with the obliteration rate (p=0.9, 0.7 respectively), as well as the risk of post-radiosurgery hemorrhage (p=0.1, 0.5 respectively).
Conclusions: In our experience, both the rates of obliteration as well as the risks of hemorrhage during the latency period were not affected by prior embolization. The role of embolization both before after CyberKnife radiosurgery for AVMs should be further explored.
Patient Care: Patients will be more knowledgeable about how prior embolization will affect obliteration of their AVMs.
Learning Objectives: By the conclusion of this session participants should be able to better understand the role that embolization plays in the efficacy of stereotactic radiosurgery for arteriovenous malformations.