Integration of a lightweight and table-mounted robotic alignment tool with automated patient-to-image registration using robotic cone-beam CT for intracranial biopsies and stereotactic electroencephalography
Authors: Truckenmueller Peter , Früh Anton , Kissner Johannes Felix , Moser Nadja Katharina , Misch Martin , Faust Katharina , Onken Julia , Vajkoczy Peter , Xu Ran 
Published: December 2024

OBJECTIVE

Robotics in neurosurgery is becoming increasingly prevalent. The integration of intraoperative imaging for patient registration into workflows of newer robotic systems enhances precision and has further driven their widespread adoption. In this study, the authors report on a lightweight, table-mounted robotic system integrating robotic cone-beam CT (CB-CT) for automated patient registration in cranial biopsies and stereotactic electroencephalography (sEEG).

METHODS

This prospective cohort study included patients who underwent stereotactic biopsy or sEEG with the Cirq system from January 2023 to August 2024. For patient-to-image registration, an external registration matrix was secured near the patient’s head before conducting CB-CT with robotic Artis Pheno. CT was then fused with preoperative planning MRI and used as the navigation dataset. Demographic and clinical data were evaluated, and entry and target errors, as well as vector deviation of sEEG electrodes, were assessed and compared with those of patients who underwent biopsies and sEEG with the frameless VarioGuide system.

RESULTS

In 26 Cirq-assisted surgical procedures, robotic CB-CT was used for image registration in 20 cases. Of these, 15 were biopsies (mean ± SD 7 ± 1 specimens) and 5 were sEEG with 31 depth electrodes, compared to 29 VarioGuide biopsies and 3 VarioGuide sEEG cases with 25 electrodes. The mean age was 56 ± 19 years, with a male/female ratio of 1.9:1. Lesion size averaged 19 ± 17 cm3 on T1-weighted imaging and 61 ± 53 cm3 on T2-weighted imaging for Cirq and 14 ± 14 cm3 and 68 ± 47 cm3 for VarioGuide. The mean surgical times were 117 ± 34 minutes for biopsy and 269 ± 54 minutes for sEEG in the Cirq group, with skin-to-skin times of 40 ± 23 minutes for biopsy and 208 ± 74 minutes for sEEG; in comparison, surgical times of 78 ± 21 minutes for biopsy and 218 ± 33 minutes for sEEG were reported with VarioGuide, with skin-to-skin times of 34 ± 13 and 158 ± 27 minutes. No complications occurred. The mean dosage area product was 983 ± 351 µGym2 for biopsies and 1772 ± 968 µGym2 for sEEG. Cirq-assisted sEEG electrodes had mean entry and target errors of 1.4 ± 1.2 mm and 2.6 ± 1.6 mm, compared to 5.3 ± 3.3 mm and 6.5 ± 2.8 mm with VarioGuide. Mean vector deviation was 1.6 ± 0.9 mm with Cirq versus 4.9 ± 2.9 mm with VarioGuide.

CONCLUSIONS

The integration of a lightweight, table-mounted robotic alignment tool with intraoperative CB-CT for automated patient-to-image registration enables high precision and a seamless workflow. This combination is safe, has a manageable learning curve, and holds potential to replace traditional frame-based and frameless procedures. Its efficiency and accuracy are likely to contribute to the increasing adoption of robotics in neurosurgery.