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.