Dynamic Intraoperative Prostate Brachytherapy Using 3D TRUS Guidance with Robot Assistance.

This paper describes a system for dynamic intraoperative prostate brachytherapy using 3D ultrasound guidance with robotic assistance. The system consists of 3D TRUS imaging, a robot and software for prostate segmentation, intraoperative planning, oblique needle segmentation and tracking, seed segmentation, and 3D dose planning. The robot and 3D TRUS coordinate systems are unified through robot and image calibrations. In 3D ultrasound images, the prostate is segmented using the discrete dynamic contour method, and optimal implantation plan is performed using geometric optimization followed by simulated annealing. The inserted needles are segmented and tracked using grey-level change in near real-time, and seed segmentation is performed using 3D line segment patterns. Needle placement accuracy of the robot at the "patient" skin was 0.15mm± 0.06mm, and needle angulation error was 0.07°. Needle targeting accuracy was 0.79mm±0.32mm.