title: Intraoperative 3D fluoroscopy in stereotactic surgery.
abstract: BACKGROUND
  Intraoperative localisation of a stereotactic probe remains challenging. Stereotactic X-ray, the "gold standard", as well as intraoperative magnetic resonance (MRI) and computed tomography (CT), require a dedicated operating room (OR). Fluoroscopy with crosshairs confirms only grossly the target position. An alternative would be a mobile three-dimensional (3D) fluoroscopy C-arm. To our knowledge, this is the first report on 3D C-arm fluoroscopy to verify stereotactical trajectories. The objective was to assess the feasibility of using a 3D C-arm to verify the intraoperative trajectory and target.
  
  
  METHODS
  A total of 12 stereotactic trajectories in 10 patients were analysed, comprising 8 biopsies and 4 electrode trajectories. The fluoroscopic scan was performed after implantation of the deep brain stimulation electrode or after advancing the biopsy needle to the tumour. An image set is acquired during a rotation of the 3D C-arm. The image set is reconstructed and merged to the preoperative CT scan. Calculating the vector error and the deviation assesses target and trajectory accuracy.
  
  
  RESULTS
  The mean trajectory deviation was 0.6 mm (±0.54 mm) and the mean vector error was 1.44 mm (±1.43 mm). There was no influence on the surgical time and the mean irradiation dosage was 401.9 cGycm(2).
  
  
  CONCLUSIONS
  This target and trajectory verification is feasible. Its accuracy seems comparable with MRI and CT. There is no additional time consumption. Irradiation is comparable with stereotactic X-ray.
authors.affiliation: Klinik für Neurochirurgie, Goethe Universität Frankfurt am Main, Germany. lutz.weise@med.uni-frankfurt.de
authors.forename: Lutz
authors.initials: L
authors.lastname: Weise
authors.forename: S
authors.initials: S
authors.lastname: Eibach
authors.forename: V
authors.initials: V
authors.lastname: Seifert
authors.forename: M
authors.initials: M
authors.lastname: Setzer
mesh_terms: D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D046690:Deep Brain Stimulation / Q000295:instrumentation / Q000379:methods; D005240:Feasibility Studies; D005471:Fluoroscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D016343:Monitoring, Intraoperative; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods