June Kim MD, Presenter: Nothing to Disclose

James Kyle Goddard MD, Abstract Co-Author: Nothing to Disclose

Leslie Nussbaum MD, Abstract Co-Author: Nothing to Disclose

Eric Nussbaum MD, Abstract Co-Author: Nothing to Disclose

Lori Copsey BS, RT, Abstract Co-Author: Nothing to Disclose

Rachel Dayton MPH, Abstract Co-Author: Nothing to Disclose

Amy Fehrer MPH, Abstract Co-Author: Nothing to Disclose

Camille Schwarzrock RN, Abstract Co-Author: Nothing to Disclose

Michelle Smith BS,RT, Abstract Co-Author: Nothing to Disclose

To examine the treatment parameters and clinical outcomes of patients with arteriovenous malformation (AVM) treated with CyberKnife® (CK) stereotactic radiosurgery (SRS).

Patients with AVM who underwent CK SRS and had at least 1 year follow-up were included in this study (n=67). Medical records were reviewed and demographic, treatment parameter and outcome data were gathered and analyzed.

Age of patients ranged from 14-75 years (mean 45). Pre-SRS AVM volume ranged from 0.027-62.72 ml (median 4.4 ml). The median prescription dose was 24 Gy in 3 fractions. Per Spetzler-Martin grading, 6 patients had grade 1, 18 had grade 2, 18 had grade 3, 8 had grade 4 and none had grade 5 AVMs. According to the Cognard classification, there were 14 dural AV fistulas (21%). Two patients had AVMs located in the vein of Galen. The rate of re-bleed was 4% (n=3). One patient experienced ischemic stroke post-SRS. Procedure related gliosis was observed in 19 patients (28%). The mean time to complete obliteration was 29 months. Thirty-four patients had malformations of <15 ml and >3 year follow-up. Of these patients, the obliteration rate for parenchymal AVMs was 75% (18/24) and 50% (4/8) for dural AV fistulas. One-hundred percent (2/2) of vein of Galen AVMs were obliterated. Eight patients had parenchymal AVMs larger than 15 ml and >3 year follow-up. The obliteration rate for these patients was 25%. No dural AV fistulas greater than 15 ml were reported. The obliteration rate was higher in patients with compact (67%) versus diffuse (22%) nidus. Five patients had obliteration prior to 3 year follow-up; two were parenchymal AVMs and three were dural AV fistulas. Although the sample size was small, there appeared to be a trend towards favorable outcomes with a dose equivalent to 15 Gy or higher in a single fraction. Three cases were re-treated following SRS. Of those, two underwent surgery and one had embolization followed by repeat SRS.

The results suggest CK SRS is an effective treatment for AVM and dural AV fistula comparable to similar treatment modalities.

Our data show favorable outcomes for parenchymal AVM and dural AV fistula obliteration with low rates of re-bleed and re-treatment.

Kim, J, Goddard, J, Nussbaum, L, Nussbaum, E, Copsey, L, Dayton, R, Fehrer, A, Schwarzrock, C, Smith, M, CyberKnife® Stereotactic Radiosurgery for Arteriovenous Malformation.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13020952.html