title: The long-term outcomes of radiosurgery for arteriovenous malformations in pediatric and adolescent populations.
abstract: OBJECT Although stereotactic radiosurgery (SRS) has been accepted as a therapeutic option for arteriovenous malformations (AVMs) in children and adolescents, substantial data are still lacking regarding the outcomes of SRS for AVMs in this age group, especially long-term complications. This study aimed to clarify the long-term outcomes of SRS for the treatment of AVM in pediatric patients aged ≤ 18 years. METHODS Outcomes of 116 patients who were aged 4-18 years when they underwent SRS between 1990 and 2009 at the study institute were analyzed retrospectively. RESULTS The median follow-up period after SRS was 100 months, with 6 patients followed up for more than 20 years. Actuarial obliteration rates at 3 and 5 years after SRS were 68% and 88%, respectively. Five hemorrhages occurred in 851 patient-years of follow-up. The annual bleeding rate after SRS before obliteration was calculated as 1.3%, which decreased to 0.2% after obliteration. Shorter maximum nidus diameter (p = 0.02) and higher margin dose (p = 0.03) were associated with a higher obliteration rate. Ten patients experienced adverse events after SRS. Of them, 4 patients presented with delayed complications years after SRS (range 9-20 years after SRS). CONCLUSIONS SRS can reduce the risk of hemorrhage in pediatric and adolescent AVMs, with an acceptable risk of complications in the long term. However, adverse events such as expanding hematoma and radiation necrosis that can occur after substantial follow-up should be taken into account at the time that treatment decisions are made and informed consent is obtained.
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Shunya
authors.initials: S
authors.lastname: Hanakita
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Koga
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shin
authors.affiliation: Radiology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Igaki
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Saito
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D016634:Radiosurgery; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
keywords: AVM = arteriovenous malformation; DTT = diffusion tensor tractography; Gamma Knife surgery; SRS = stereotactic radiosurgery; arteriovenous malformation; children; stereotactic radiosurgery