Robotic-aided 3D TRUS guided intraoperative prostate brachytherapy

Abstract

We have developed a robotic aided 3D transrectal ultrasound (TRUS) guided, intraoperative prostate brachytherapy. This system allows brachytherapy needles to be inserted into the prostate along various trajectories including oblique to avoid pubic arch interference. We unified the robotic coordinate system with the 3D TRUS image coordinate system. In addition, we also hdeveloped the method to automatically detect the needle in TRUS images for oblique insertion. We have evaluated our prototype system using prostate phantoms in terms of different needle insertion depths and the distances of the needle from the TRUS transducer. We have shown that our robotic aided 3D TRUS guided system was capable of placing the needle tip with approximately 0.74 mm ± 0.24 mm accuracy at a target identified in the 3D TRUS image. Brachytherapy accuracy was tested by dropping 0.8 mm beads into prostate phantoms via various angles up to ± 20°. Our results showed that the bead-dropping accuracy was 2.59 mm ± 0.76 mm with the error due to the needle deflection caused by the needle's bevel.