Puncture accuracy of an optical tracked robotic aiming device-a phantom study

Objectives To evaluate the targeting accuracy of stereotactic punctures based on a hybrid robotic device in combination with optical tracking-a phantom study. Methods CT data sets of a gelatin-filled plexiglass phantom with 1-, 3-, and 5-mm slice thickness were acquired. An optical navigation device served for planning of a total of 150 needle trajectories. All punctures were carried out semi-automatically with help of the trackable iSYS-1 robotic device. Conically shaped targets inside the phantom were punctured using Kirschner wires. Up to 8 K-wires were positioned sequentially based on the same planning CT and placement accuracy was assessed by taking control CTs and measuring the Euclidean (ED) and normal distances (NDs) between the wire and the entry and target point. Results Using the StealthStation S7, the accomplished mean ND at the target for the 1-mm, 3-mm, and 5-mm slice thickness was 0.89 mm (SD +/- 0.42), 0.93 mm (SD +/- 0.45), and 0.73 mm (SD +/- 0.50), respectively. The corresponding mean ED was 1.61 mm (SD +/- 0.36), 2.04 mm (SD +/- 0.59), and 1.76 mm (SD +/- 0.45). The mean duration of the total procedure was 27.9 min, including image acquisition, trajectory planning, registration, placement of 8 wires, and the control-CT. Conclusions The optically tracked iSYS-1 robot allows for precise punctures in a phantom. The StealthStation S7 provided acceptable results and may be helpful for interventions in difficult anatomical regions and for those requiring complex multi-angle trajectories. In combination with our optical navigation tool, the trackable robot unit allows to cover a large treatment field and the compact design facilitates placement of needle-like instruments.

Automated summary

This study evaluated the targeting accuracy of stereotactic punctures using a hybrid robotic device and optical tracking. The results demonstrated that this method achieved high accuracy and feasibility in puncturing a phantom.