Clinical and radiologic follow-up of 86 patients with symptomatic, but surgically inaccessible, cerebral arteriovenous malformations treated with stereotactic heavy charged particle Bragg-peak radiation is reported from the Divisions of Neurosurgery and Neuradiology, Stanford University School of Medicine, California and the Lawrence Berkeley Laboratory, University of California. Ages at the time of treatment were from 9 to 69 years (mean, 33). Presenting symptoms were hemorrhage (60 patients), neurologic deficits (11), seizures (35), and headaches (40). Three years after radiation treatment the rate of complete obliteration of the lesions as detected angiographically was 100% for smaller lesions and 70% for those larger than 25 cm3. Major neurologic complications occurred in ten patients (12%). Seizures and headaches were less severe in the patients who suffered from these initially. The authors concluded that heavy charged particle radiation is effective for symptomatic surgically inaccessible intracranial AV malformations. Disadvantages of this therapy include the long delay in obliteration of the vascular lesion and a small risk of serious neurologic complications. 
COMMENT: In an editorial comment by Heros R C and Korosue K of the University of Minnesota, Minneapolis, it is pointed out that the rate of serious morbidity from a hemorrhage from an arteriovenous malformation is about 30% and the mortality rate is about 10%. Not to treat is an unattractive choice for younger patients who will remain at risk for the rest of their lives. In considering the results of radiation therapy for AV malformations, the morbidity and mortality resulting from hemorrhage after treatment must be considered, particularly in comparing irradiation with surgical excision, a treatment method which eliminates the risk of hemorrhage. The delayed adverse effects of radiation on nervous tissue may limit this form of therapy in children. Only patients with previous hemorrhage, severe neurologic deficits, uncontrolled seizures, or disabling headaches were accepted in the author's protocol which included mainly adults.