Introduction: This study investigates the clinical and imaging outcomes of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the sylvian fissure.
Methods: A retrospective analysis was conducted on 87 patients who underwent a single radiosurgery procedure for AVMs located in the sylvian fissure in the interval of 1987 to 2009. The median age was 38 years (range 9-77). Thirty-six patients (41%) experienced seizures prior to SRS, and in 29 this was the presenting symptom that led to their AVM diagnosis . Hemorrhage was the initial presentation in 40 patients (46%). The median marginal dose was 20 Gy (range 13-25Gy), and 3.85cm3 (range 0.1-17.7cm3) was the median treatment volume.
Results: At a median follow-up of 64 months (range 3–275 months), 43 patients had AVM obliteration documented by MRI or angiography. The 3, 4, 5, and 10-year actuarial total obliteration rates were 35%, 60%, 60% and 76% respectively. Larger volumes and maximum AVM diameters were negatively correlated with obliteration rates (p=0.027). Higher margin doses were positively correlated (p=0.009). Eighteen patients (50%) showed improvement in Engel seizure classification. The rates of seizure improvement were 26%, 32%, 51%, and 67% at 3, 5, 10 and 15 years respectively. Four patients (4.6%) experienced a hemorrhage during the latency period, and one patient died. The annual hemorrhage rate during the latency interval was 1%, and no patient sustained a hemorrhage after confirmed obliteration. A single patient suffered a permanent neurological deficit due to adverse radiation effects (ARE). Three patients had delayed cyst formation.
Conclusions: Stereotactic radiosurgery provided an effective treatment for AVMs in the sylvian fissure. This is reinforced by the relatively low hemorrhage rate during the latency period, and substantial improvement in seizure control over time.
Patient Care: This paper provides evidence to support clinical decision making in regard to treatment options of AVMs in the sylvian fissure.
Learning Objectives: To investigates and understand the clinical and imaging outcomes of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the sylvian fissure, as well as seizure outcomes in this region.