Stereotactic radiosurgery at a low marginal dose for the treatment of pediatric arteriovenous malformations: obliteration, complications, and functional outcomes.
OBJECT.: Stereotactic radiosurgery (SRS) is an established treatment modality for brain arteriovenous malformations (AVMs) in children, but the optimal treatment parameters and associated treatment-related complications are not fully understood. The authors present their single-institution experience of using SRS, at a relatively low marginal dose, to treat AVMs in children for nearly 20 years; they report angiographic outcomes, posttreatment hemorrhage rates, adverse treatment-related events, and functional outcomes.


METHODS
The authors conducted a retrospective review of 2 cohorts of children (18 years of age or younger) with AVMs treated from 1991 to 1998 and from 2000 to 2010.


RESULTS
A total of 80 patients with follow-up data after SRS were identified. Mean age at SRS was 12.7 years, and 56% of patients had hemorrhage at the time of presentation. Median target volume was 3.1 cm(3) (range 0.09-62.3 cm(3)), and median prescription marginal dose used was 17.5 Gy (range 12-20 Gy). Angiograms acquired 3 years after treatment were available for 47% of patients; AVM obliteration was achieved in 52% of patients who received a dose of 18-20 Gy and in 16% who received less than 18 Gy. At 5 years after SRS, the cumulative incidence of hemorrhage was 25% (95% CI 16%-37%). No permanent neurological deficits occurred in patients who did not experience posttreatment hemorrhage. Overall, good functional outcomes (modified Rankin Scale Scores 0-2) were observed for 78% of patients; for 66% of patients, functional status improved or remained the same as before treatment.


CONCLUSIONS
A low marginal dose minimizes SRS-related neurological deficits but leads to low rates of obliteration and high rates of hemorrhage. To maximize AVM obliteration and minimize posttreatment hemorrhage, the authors recommend a prescription marginal dose of 18 Gy or more. In addition, SRS-related symptoms such as headache and seizures should be considered when discussing risks and benefits of SRS for treating AVMs in children.
Departments of Neurological Surgery.
Matthew B
MB
Potts
Sunil A
SA
Sheth
Jonathan
J
Louie
Matthew D
MD
Smyth
Penny K
PK
Sneed
Michael W
MW
McDermott
Michael T
MT
Lawton
William L
WL
Young
Steven W
SW
Hetts
Heather J
HJ
Fullerton
Nalin
N
Gupta
D000293:Adolescent; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D011829:Radiation Dosage; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome
AVM = arteriovenous malformation; SRS = stereotactic radiosurgery; UCSF = University of California, San Francisco; arteriovenous malformation; mRS = modified Rankin Scale; pediatric; stereotactic radiosurgery; vascular disorders