title: Multistaged volumetric management of large arteriovenous malformations.
abstract: We sought to define the long-term outcomes and risks of arteriovenous malformation (AVM) management using 2 or more stages of stereotactic radiosurgery (SRS) for symptomatic large-volume AVMs unsuitable for surgery. Two decades ago, we prospectively began to stage anatomical components in order to deliver higher single doses to AVMs>10 cm3 in volume. Forty-seven patients with large AVMs underwent volume-staged SRS. The median interval between the two SRS procedures was 4.9 months (range, 3-14 months). The median nidus volume was 11.5 cm3 (range, 4.0-26 cm3) in the first stage of SRS and 9.5 cm3 in the second. The median margin dose was 16 Gy (range, 13-18 Gy) for both SRS stages. The actuarial rates of total obliteration after 2-staged SRS were 7, 20, 28 and 36% at 3, 4, 5 and 10 years, respectively. Sixteen patients needed additional SRS at a median interval of 61 months (range, 33-113 months) after the 2-staged SRS. After repeat procedure(s), the eventual obliteration rate was 66% at 10 years. The cumulative rates of AVM hemorrhage after SRS were 4.3, 8.6, 13.5 and 36.0% at 1, 2, 5 and 10 years, respectively. Symptomatic adverse radiation effects were detected in 13% of patients. Successful prospective volume-staged SRS for large AVMs unsuitable for surgery requires 2 or more procedures to complete the obliteration process. Patients remain at risk for hemorrhage if the AVM persists.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kano
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: Kyung-Jae
authors.initials: KJ
authors.lastname: Park
authors.forename: Phillip V
authors.initials: PV
authors.lastname: Parry
authors.forename: Huai-che
authors.initials: HC
authors.lastname: Yang
authors.forename: Sait
authors.initials: S
authors.lastname: Sirin
authors.forename: Ajay
authors.initials: A
authors.lastname: Niranjan
authors.forename: Josef
authors.initials: J
authors.lastname: Novotny
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
mesh_terms: D000293:Adolescent; D000328:Adult; D001164:Arteriovenous Fistula / Q000175:diagnosis* / Q000601:surgery*; D002648:Child; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods*; D055815:Young Adult