Stereotactic radiosurgery of cerebral arteriovenous malformations with a multileaf collimator and a single isocenter.
OBJECTIVE
To prospectively demonstrate the safety and efficacy of stereotactic radiosurgery for arteriovenous malformations (AVMs) of the brain with a linear accelerator fitted with a multileaf collimator.


METHODS
A novel radiosurgery system was developed at the University of Michigan Medical Center with a standard multileaf collimator and a computer-controlled radiotherapy system. Data were accumulated prospectively on all patients undergoing treatment with this system since treatment began in 1995.


RESULTS
Thirty-six patients with 37 AVMs have undergone treatment to date. At more than 3 years since treatment, 15 of 16 AVMs with a volume of less than 10 cc were proven to be obliterated by angiography or magnetic resonance imaging, and one was considered a treatment failure. At more than 24 months since therapy, all four AVMs with a volume of 10 to 25 cc were obliterated. Four patients with AVMs with a volume of more than 25 cc have undergone staged therapy, treating the entire volume to 10 Gy twice, but none has been followed long enough to demonstrate a final outcome. There were four transient and no permanent complications.


CONCLUSIONS
Our early data indicate that stereotactic radiosurgery of cerebral AVMs with a linear accelerator and a multileaf collimator is safe and effective. Large AVMs may be especially suitable for this mode of therapy. Staged treatment of very large AVMs seems to be a promising addition to standard treatment, but longer follow-up is necessary to confirm that complete obliteration can be achieved.
Department of Surgery, University of Michigan, Ann Arbor, USA.
D A
DA
Ross
H M
HM
Sandler
J M
JM
Balter
J A
JA
Hayman
J
J
Deveikis
D L
DL
Auer
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery / Q000295:instrumentation*