Artikel
Stereotactic electrode localization in deep brain stimulation: validation of an alternative X-ray stereotactic tool
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Autoren
Veröffentlicht: | 4. Mai 2005 |
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Gliederung
Text
Objective
The aim of this study was to evaluate the accuracy of our stereotactic procedure for deep brain stimulation in an operating room without teleradiology: we report our alternative technique to documente stepwise location of the microelectrode during surgery, and the final location of the poles of stimulation lead.
Methods
Twelve bilateral implantation procedures were performed using direct targeting of the subthalamic nucleus on magnetic resonance (MR). On the stereotactic frame (Fisher RM, Open ceremic version, Strycker-Leibinger) were mounted x-ray localizer plates, giving opportunity for exact calculation of coordinates for each microelectrodes tips or final contact, by digitization and transformation of the X-ray image, with stereotactic software (Stereoplan, Leibinger). (i) We compared the peroperative coordinates obtained by this method with the theorical coordinates calculated from the preoperative MR. (ii) The final position of the 4 contacts were determinated with Stereoplan. Afterward, postoperative MR is fused with preoperative, and the positions of the 4 contacts were compared with the final peroperative X-ray acquisitions.
Results
(i) Concerning the peroperative location of the microelectrodes, the mean deviation values in the 3 axis between coordinates mesured with stereoplan and coordinates calculated from planned MR were (in mms) : Δx=0.84 [0-3.7], Δy=0.87 [0-3.4], Δz=0.89 [0-3.7]. (ii) Concerning the final position of the four contacts of the DBS leads, the mean deviation values in the 3 axis between final stereotactic X-ray and postoperative MR were (in mms) : Δx=0.42 [0-1.7], Δy=0.71 [0-0.9], Δz=0.55 [0-1.5]. The 3D euclidian error was 1.00mm.
Conclusions
In absence of a real teleradiologic tool in our operating room, we developed a procedure to determine stereotactic coordinates for test-electrodes and for final electrodes contacts. The infra-millimetric accuracy of the system allows a stepwise intraoperative verification, in accordance with the planned trajectory. In a second hand, this X-ray stereotactic system is helpfull to determine final location of the contacts without risk of MR-related slight distorsion.