title: Gamma Knife surgery for arteriovenous malformations in the brain: integration of time-resolved contrast-enhanced magnetic resonance angiography into dosimetry planning. Technical note.
abstract: OBJECTIVE
  The aim of this study was to develop an algorithm for the integration of time-resolved contrast-enhanced magnetic resonance (MR) angiography into dosimetry planning for Gamma Knife surgery (GKS) of arteriovenous malformations (AVMs) in the brain.
  
  
  METHODS
  Twelve patients harboring brain AVMs referred for GKS underwent intraarterial digital subtraction (DS) angiography and time-resolved MR angiography while wearing an externally applied cranial stereotactic frame. Time-resolved MR angiography was performed on a 1.5-tesla MR unit (Achieva, Philips Medical Systems) using contrast-enhanced 3D fast field echo sequencing with stochastic central k-space ordering. Postprocessing with interactive data language (Research Systems, Inc.) produced hybrid data sets containing dynamic angiographic information and the MR markers necessary for stereotactic transformation. Image files were sent to the Leksell GammaPlan system (Elekta) for dosimetry planning.
  
  
  RESULTS
  Stereotactic transformation of the hybrid data sets containing the time-resolved MR angiography information with automatic detection of the MR markers was possible in all 12 cases. The stereotactic coordinates of vascular structures predefined from time-resolved MR angiography matched with DS angiography data in all cases. In 10 patients dosimetry planning could be performed based on time-resolved MR angiography data. In two patients, time-resolved MR angiography data alone were considered insufficient. The target volumes showed a notable shift of centers between modalities.
  
  
  CONCLUSIONS
  Integration of time-resolved MR angiography data into the Leksell GammaPlan system for patients with brain AVMs is feasible. The proposed algorithm seems concise and sufficiently robust for clinical application. The quality of the time-resolved MR angiography sequencing needs further improvement.
authors.affiliation: Department of Neuroradiology, Hôpital Roger Salengro, University Hospital Lille, France. c.taschner@web.de
authors.forename: Christian A
authors.initials: CA
authors.lastname: Taschner
authors.forename: Vianney
authors.initials: V
authors.lastname: Le Thuc
authors.forename: Nicolas
authors.initials: N
authors.lastname: Reyns
authors.forename: Juergen
authors.initials: J
authors.lastname: Gieseke
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Gauvrit
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pruvo
authors.forename: Xavier
authors.initials: X
authors.lastname: Leclerc
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology* / Q000601:surgery*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*
chemical_list: D003287:Contrast Media