Stereotactic Radiosurgery for Arteriovenous Malformations with Hemorrhage History: the University of Pittsburgh Experience in 407 Consecutive PatientsHideyuki Kano, PhD, MD1, Douglas Kondziolka, MD1, John Flickinger, MD1, Huai-che Yang, MD1, Kyung-Jae Park, MD, PhD1, Thomas Flannery, MD, PhD1, Ajay Niranjan1, L. Dade Lunsford, MD11Pittsburgh, PA United States Keywords: arteriovenous malformation, radiosurgery, gamma knife, hemorrhage, outcome
AVM hemorrhage is a risk factor for repeat hemorrhage.
To define the outcomes and risks of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) with hemorrhage history.
Between 1987 and 2006, SRS was performed on 407 AVM patients with hemorrhage history.
The median target volumes and margin dose were 2.3 cc (0.1-20.7 cc) and 20 Gy (13.5-32 Gy), respectively. Sixty-four patients (16%) underwent prior embolization and 84 (21%) underwent prior surgical resection.
The overall rates of total obliteration documented by angiography or MR were 57%, 77%, 80%, and 82% at 3, 4, 5, and 10 years, respectively at a median follow-up of 66 months. The overall rates of total obliteration documented by angiography were 46%, 65%, 68%, and 70% at 3, 4, 5, and 10 years, respectively. Factors associated with a higher rate of AVM obliteration were no smaller target volume, and higher margin dose. Twenty-nine patients (7%) had a hemorrhage during the latency interval and 14 patients died due to hemorrhage. The rate of AVM hemorrhage after SRS was 2.7%, 3.8%, 5.0%, 6.1%, and 8.1% at 1, 2, 3, 5, and 10 years, respectively. The annual hemorrhage rate after SRS was 3.4%. Factors associated with higher hemorrhage rate included coexisting aneurysm and larger nidus volume. Symptomatic AREs were detected in 7%, and associated with a 12 Gy volume and lower margin dose. Delayed cyst formations were detected in 11 patients with a median of 38 months.
This is a retrospective study.
SRS is an effective and relatively safe management option for AVMs.
Patients remain at risk during the latency interval until obliteration occurs. Project Roles:
H. Kano (), D. Kondziolka (), J. Flickinger (), H. Yang (), K. Park (), T. Flannery (), A. Niranjan (), L. Lunsford ()