Stereotactic radiosurgery and fractionated radiotherapy for spinal arteriovenous malformations - A systematic review of the literature.

Spinal arteriovenous malformations (AVMs) comprise a group of complex vascular lesions whose treatment with microsurgery or transarterial embolization can be challenging. Stereotactic radiosurgery is a well-established treatment for intracranial AVMs, and spinal radiosurgery and fractionated radiotherapy are common treatments for spinal tumors of both primary and metastatic origin. The use of radiosurgery and fractionated radiotherapy for the treatment of spinal arteriovenous malformations, however, has been infrequently reported. Spinal stereotactic radiosurgery is emerging as a promising option for the treatment of these lesions. We conducted a systematic review of English language articles reporting one or more cases of spinal radiosurgery or fractionated radiotherapy for the treatment of spinal arteriovenous fistulas (AVFs) or arteriovenous malformations. Eight unique studies comprising 64 patients were identified. All treated lesions consisted primarily of spinal AVMs, either intramedullary or metameric. Most were treated with CyberKnife technology. Marginal doses in the most current studies ranged from 18 to 21 Gy given over 2-4 fractions. In aggregate, good outcomes were reported in 92.2% with no instances of post-treatment hemorrhage over a mean follow-up time of 46.8 months. Angiographic follow-up showed the nidus to be obliterated in 16%, decreased in 44.6%, and unchanged in 39.3%. Stereotactic radiosurgery for spinal arteriovenous malformations holds promise as a safe and potentially effective option in the treatment of these rare but complex lesions.