Robotically Assisted CBCT-Guided Needle Insertions: Preliminary Results in a Phantom Model

To compare robotic-assisted needle insertions performed under CBCT guidance to standard manual needle insertions.

A homemade robotic prototype was used by two operators to perform robotic and manual needle insertions on a custom-made phantom. Both the operators had no experience with the prototype before starting the trial. The primary endpoint was accuracy (i.e., the minimal distance between the needle tip and the center of the target) between robotic and manual insertions. Secondary endpoints included total procedure time and operators' radiation exposure. The Wilcoxon test was used. A p value less than 0.05 was considered statistically significant.

Thirty-three (17 manual, 16 robotic) needle insertions were performed. Mean accuracy for robotic insertion was 2.3 ± 0.9 mm (median 2.1; range 0.8-4.2) versus 2.3 ± 1 mm (median 2.1; range 0.7-4.4) for manual insertion (p = 0.84). Mean procedure time was 683 ± 57 s (median 670; range 611-849) for the robotic group versus 552 ± 40 s (median 548; range 486-621) for the manual group (p = 0.0002). Mean radiation exposure was 3.25 times less for the robotic insertion on comparison to manual insertion for the operator 1 (0.4 vs 1.3 µGy); and 4.15 times less for the operator 2 (1.9 vs 7.9 µGy).

The tested robotic prototype showed accuracy comparable to that achieved with manual punctures coupled to a significant reduction of operators' radiation exposure. Further, in vivo studies are necessary to confirm the efficiency of the system.