gms | German Medical Science

Objective: We evaluated the 10-year follow-up of pediatric intracerebral arteriovenous malformations (AVMs) treated with Gamma Knife radiosurgery (GKRS).

Methods: GKRS was performed on 34 children suffering from intracerebral AVM. 12 children were treated by a single radiosurgical procedure and 4 by repeated GKRS. In 18 children GKRS was performed as secondary therapy after operation and/or embolization. The median lesion diameter was 17.3 mm (range 6 to 33 mm) treated by a median dose of 21 Gy (range 12.5 to 28 Gy). The median margin isodose was the 50% isodose (range 40% to 90%).

Results: Median follow-up of the 23 children was 79 months (range 24 to 162 months). In 16 cases complete obliteration was proven by angiography, in one case by MR-angiography after 3.5 years. In 6 patients only partial obliteration was seen. In the recent literature a 75% obliteration rate 3 years after GKRS has been reported. According to our experience a marginal dose of 20 Gy on the 50% isodose is most effective. In our series AVMs of a volume smaller than 3 cm³ showed better and faster obliteration than those exceeding this size. In 2 cases radiosurgery-related complications occurred after GKRS without any permanent neurological deficit. In the literature a risk of 2–3% is mentioned for radiation effects with permanent neurological deficit. Hemorrhage was noted in one child 10 months after GKRS (4% incidence in recent literature).

Conclusions: GKRS is a safe and effective technique in the treatment of pediatric AVMs. Especially those graded as Spezler-Martin grade 3 (small volume, deeply located) seem to be most suitable for GKRS. In larger AVMs treatment with additional embolization, operation or staged radiosurgical procedure is recommended.