Stereotactic radiosurgery for thalamus arteriovenous malformations.

Background: Cerebral arteriovenous malformations or angiomas are congenital vascular anomalies defined by abnormal arteriovenous shunt.

Materials and methods: We conducted a retrospective study between January 1992 and December 2010 at the Timone Hospital radiosurgery unit, 1557 patients were treated by radiosurgery for arteriovenous malformation of which 53 for thalamic localization (3,4%).

Results: The mean age was 35.8-/+16.6 years (4-75). 14 patients underwent pre-radiosurgical embolization (26.4%), discovery mode for 47 patients (88.7%) was haemorrhage. The average treatment volume was 1.43 cm³. The average RBAS score was 1.36. The average prescription to the 50% isodose envelope delivered was 22.9 +/-2.9 Gy (12-30), the median margin dose was 24 Gy. Our global obliteration rate after one or two procedures 66.7% for an average follow-up period of 56.7 months. We noted 3.9% of mortality, 5.9% of bleeding after procedure and 3.9% of radio-induced neurological deficit.

Conclusion: Radiosurgery became indispensable in the treatment of thalamic AVM even when there is a persistent risk of haemorrhage until total recovery.