Endovascular therapy followed by stereotactic radiosurgery for cerebral arteriovenous malformations

Pre-radiosurgical embolization was carried out using cyanoacrylate in seven of 13 patients with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS) with a linear accelerator (LINAC). The aim of embolization before SRS was the reduction of AVM volume and/or the elimination of vascular structures bearing an increased risk of haemorrhage. Staged-volume SRS was also performed in two patients because of residual irregular shaped nidus of AVMs even after the embolizations. Complete obliteration of the AVM nidus on angiogram was presented in five patients with embolizations (including one with staged-volume SRS) and in three of six patients with SRS alone, during follow-up periods after radiosurgery. No patients experienced haemorrhagic events after SRS. Although transient neurological symptoms were observed after embolizations in two patients, no permanent neurological deficits were presented in all patients with SRS. Pre-radiosurgical embolization may allow the effective influence on irradiation therapy in relatively large AVMs and promote more frequent obliteration in more small sized AVMs compared to those with SRS alone. However, further study must be needed to determine whether staged-volume SRS provides a high rate of AVM obliteration and its safeness.