AUTHOR=Oermann Eric K. , Murthy Nikhil , Chen Viola , Baimeedi Advaith , Sasaki-Adams Deanna , McGrail Kevin , Collins Sean P. , Ewend Matthew G. , Collins Brian T. 

TITLE=A Multicenter Retrospective Study of Frameless Robotic Radiosurgery for Intracranial Arteriovenous Malformation

JOURNAL=Frontiers in Oncology

VOLUME=4

YEAR=2014

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2014.00298

DOI=10.3389/fonc.2014.00298

ISSN=2234-943X

ABSTRACT=<p><bold>Introduction:</bold> CT-guided, frameless radiosurgery is an alternative treatment to traditional catheter-angiography targeted, frame-based methods for intracranial arteriovenous malformations (AVMs). Despite the widespread use of frameless radiosurgery for treating intracranial tumors, its use for treating AVM is not-well described.</p><p><bold>Methods:</bold> Patients who completed a course of single fraction radiosurgery at The University of North Carolina or Georgetown University between 4/1/2005–4/1/2011 with single fraction radiosurgery and received at least one follow-up imaging study were included. All patients received pre-treatment planning with CTA ± MRA and were treated on the CyberKnife (Accuray) radiosurgery system. Patients were evaluated for changes in clinical symptoms and radiographic changes evaluated with MRI/MRA and catheter-angiography.</p><p><bold>Results:</bold> Twenty-six patients, 15 male and 11 female, were included in the present study at a median age of 41 years old. The Spetzler-Martin grades of the AVMs included seven Grade I, 12 Grade II, six Grade III, and one Grade IV with 14 (54%) of the patients having a pre-treatment hemorrhage. Median AVM nidal volume was 1.62 cm<sup>3</sup> (0.57–8.26 cm<sup>3</sup>) and was treated with a median dose of 1900 cGy to the 80% isodose line. At median follow-up of 25 months, 15 patients had a complete closure of their AVM, 6 patients had a partial closure, and 5 patients were stable. Time since treatment was a significant predictor of response, with patients experience complete closure having on average 11 months more follow-up than patients with partial or no closure (<italic>p</italic> = 0.03). One patient experienced a post-treatment hemorrhage at 22 months.</p><p><bold>Conclusion:</bold> Frameless radiosurgery can be targeted with non-invasive MRI/MRA and CTA imaging. Despite the difficulty of treating AVM without catheter angiography, early results with frameless, CT-guided radiosurgery suggest that it can achieve similar results to frame-based methods at these time points.</p>