Stereotactic heavy-particle irradiation of intracranial arteriovenous malformations.

Stereotactic irradiation appears to be effective in causing partial or complete thrombosis of AVM that are not surgically resectable. Use of heavy particles generated in a cyclotron allows better spatial definition and dose distribution than do other methods, allowing larger AVM to be treated. From these preliminary results, it is evident that heavy-particle irradiation therapy, like proton beam therapy, does not offer protection from recurrent hemorrhage for at least 12 months, nor is it devoid of major complications; it does offer a noninvasive mode of therapy for AVM that are difficult to treat surgically, however.