title: Use of cone-beam computed tomography angiography in planning for gamma knife radiosurgery for arteriovenous malformations: a case series and early report.
abstract: BACKGROUND
  The effectiveness of Gamma Knife radiosurgery (GKR) for cerebral arteriovenous malformations (AVMs) is predicated on inclusion of the entire nidus while excluding normal tissue. As such, GKR may be limited by the resolution and accuracy of the imaging modality used in targeting.
  
  
  OBJECTIVE
  We present the first case series to demonstrate the feasibility of using ultrahigh-resolution C-arm cone-beam computed tomography angiography (CBCT-A) in AVM targeting.
  
  
  METHODS
  From June 2009 to June 2013, CBCT-A was used for targeting of all patients with AVMs treated with GKR at our institution. Patients underwent Leksell stereotactic head frame placement followed by catheter-based biplane 2-dimensional digital subtraction angiography, 3-dimensional rotational angiography, as well as CBCT-A. The CBCT-A dataset was used for stereotactic planning for GKR. Patients were followed at 1, 3, 6, and 12 months and then annually thereafter.
  
  
  RESULTS
  CBCT-A-based targeting was used in 22 consecutive patients. CBCT-A provided detailed spatial resolution and sensitivity of nidal angioarchitecture enabling treatment. The average radiation dose to the margin of the AVM nidus corresponding to the 50% isodose line was 15.6 Gy. No patient had treatment-associated hemorrhage. At early follow-up (mean, 16 months), 84% of patients had a decreasing or obliterated AVM nidus.
  
  
  CONCLUSIONS
  CBCT-A-guided radiosurgery is feasible and useful because it provides sufficient detailed resolution and sensitivity for imaging brain AVMs.
authors.affiliation: *Cerebrovascular and Endovascular Division, Department of Neurosurgery, ‡Department of Radiation Oncology, Tufts Medical Center and Tufts University School of Medicine, Boston, Massachusetts; §Boston Gamma Knife Center, Boston, Massachusetts.
authors.forename: Mina G
authors.initials: MG
authors.lastname: Safain
authors.forename: Jason P
authors.initials: JP
authors.lastname: Rahal
authors.forename: Ami
authors.initials: A
authors.lastname: Raval
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Rivard
authors.forename: John E
authors.initials: JE
authors.lastname: Mignano
authors.forename: Julian K
authors.initials: JK
authors.lastname: Wu
authors.forename: Adel M
authors.initials: AM
authors.lastname: Malek
mesh_terms: D000328:Adult; D001164:Arteriovenous Fistula / Q000601:surgery*; D002533:Cerebral Angiography / Q000379:methods; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D016634:Radiosurgery; D016896:Treatment Outcome