Feasibility and Accuracy of Mri-based, Robot-assisted, Stereotactic Biopsy Using 3D Intraoperative Imaging and Frameless Patient Registration Tool. the Sainte Anne Hospital Experience

Introduction: In stereotaxic biopsies, the difference between the planned target and the actual one is not studied due to the absence of intraoperative control imaging. The purpose of this study is to investigate the accuracy and effectiveness of the robot-assisted frameless stereotaxic biopsy with intraoperative 3D control.

Methods: We performed a retrospective, monocentric study analyzing the first adult patients who underwent consecutive (2019-2021) frameless stereotaxic biopsy using an MRI-based robot with intraoperative CT scan control. Trajectory planning is performed on the 3D sequences of preoperative T1 gadolinium. Intraoperatively, the 3D acquisitions performed are co-registered with the preoperative planning via a software that allows you to confirm the alignment of the biopsy cannula with the planned trajectory. A control CT scan is performed systematically 1 day after surgery.

Results: In the series (n=100), a mean of 6.5 ± 2.3 biopsy samples and a mean of 1.7 ± 0.7 biopsy sites were obtained per patient. Diagnosis was obtained in 96% of cases. The average time of the procedure was 58 minutes. The average accuracy of the actual target compared to the planned target was 0.8mm±0.9mm. A postoperative decrease in 20 of KPS was observed in 4% of cases resulting in postoperative disability. The number of sites and biopsy specimens were not found to be independent risk factors for complication. The intraoperative radiation dose emitted (at least three 3D acquisitions) was 159.73 mGy.cm, 5 to 10 times lower than a conventional brain CT.

Conclusion : In our experience, this technique has proved to be efficient, fast, with a low complication rate, and low radiation emission. The analysis of the normalized trajectories shows the accuracy regardless of the position of the tumor, confirming the importance of pre-operative planning and intraoperative control techniques for this type of procedure.