gms | German Medical Science

Objective: To compare stereotactic frame registration with computed tomography (CT) or 3D fluoroscopy (XT) for accuracy and precision of lead implantation, efficiency, and radiation dose delivered in frame-based deep brain stimulation (DBS) surgery.

Methods: A retrospective chart review was performed that included patients with movement disorders that underwent DBS surgery at our centre by the same surgeon between December 2016 and August 2019. Patients received frame registration with either CT or XT. The actual site of electrode placement on postoperative CT was compared to the planned lead trajectory on preoperative CT to determine mean absolute differences and Euclidean distance for precision and accuracy of implantation. Efficiency was measured as the time required to register the stereotactic frame (i.e. the time between the patient entering the OR and the initial skin incision). The radiation exposure from CT or XT was measured by the dose length product (DLP). These parameters were compared between CT and XT patient groups using a one-way ANOVA.

Results: Twenty-five patients in the CT group and 16 in the XT group underwent DBS surgery (Table 1 [Tab. 1]). The mean absolute difference between patient groups did not differ significantly differ for the x (p=0.331), y (p=0.951) or z (p=0.807) coordinates (Table 2 [Tab. 2]). The Euclidean distance (± standard error of the mean, or SEM) between the CT group (2.11 ± 0.25 mm) and XT group (2.17 ± 0.21 mm) was not significantly different (p=0.874). The mean radiation dose (± standard deviation, or SD) delivered by CT was 1269.3 ± 112.9 mGy*cm, which was significantly higher than XT (220.0 ± 0.1 mGy*cm) (p<0.001). The difference in frame registration time (± SD) between CT (107.8 ± 23.1 minutes) and XT (106.0 ± 18.2 minutes) did not reach statistical significance (p=0.518).

Conclusion: XT-based frame registration was shown to result in accurate lead implantation, which did not significantly differ from CT. XT was shown to result in significantly lower radiation exposure, which may improve both patient and provider safety. Surprisingly, registration time was not significantly different between patient groups, but this might be attributed to a learning curve effect as XT was only recently introduced at our centre for DBS. Future studies might further examine the difference in registration time between these patient groups and explore complications and clinical outcomes associated with XT-based registration.