Clinical experiences and accuracy of stereoelectroencephalography using the robotic arm Cirq

Robot-assisted stereoelectroencephalography (SEEG) has become increasingly popular worldwide. Robotic arm Cirq (BrainLab, Munich, Germany) is an optional instrument for SEEG. This study aimed to evaluate the accuracy of electrode implantation using Cirq.

Data were retrospectively collected from 10 consecutive SEEG cases from July 2022 to August 2024 at our institute. Two cases of simultaneous SEEG and grid implantation via craniotomy were excluded. Eight SEEG cases (37 depth electrodes) were included in this study. We evaluated the accuracy of the electrode placement. The distances between the planned and actual site of entry and the target were measured in the anterior-posterior (Xe, Xt) and cranial-caudal (Ye, Yt) directions. The distance between the planned and the actual target site was measured at the surface depth (Zt). The two-dimensional differences of the entry (De₂) and target (Dt₂) and the three-dimensional differences, including the depth parameter of the target (Dt), were measured. The two-dimensional and three-dimensional Euclidean distances (ED₂, ED) were also calculated.

The differences between the planned entry and the actual entry in Xe and Ye were 2.5 ± 1.6 mm and -0.6 ± 1.8 mm, respectively. De₂ was 3.2 ± 1.4 mm. The differences between the planned target and the actual target in Xt, Yt, and Zt were 2.1 ± 1.5 mm, 0.5 ± 1.5 mm, and 1.4 ± 2.9 mm, respectively. Dt₂ and Dt were 2.7 ± 1.4 mm and 4.1 ± 1.7 mm, respectively. ED₂ and ED were 1.8 ± 1.1 mm and 3.4 ± 1.8 mm, respectively.

We reported our initial experience with a high accuracy and features of the Cirq robotic arm for SEEG procedures using the standard surface matching method.