We present a robot-assisted approach for transrectal ultrasound (TRUS) guided prostate biopsy. The robot is a hands-free probe manipulator that moves the probe with the same 4 degrees-of-freedom (DoF) that are used manually. Software was developed for 3D imaging, biopsy planning, robot control, and navigation. Methods to minimize the deformation of the prostate caused by the probe at 3D imaging and needle targeting were developed to reduce biopsy targeting errors. We also present a prostate coordinate system (PCS). The PCS helps defining a systematic biopsy plan without the need for prostate segmentation. Comprehensive tests were performed, including 2 bench tests, 1 imaging test, 2 in vitro targeting tests, and an IRB-approved clinical trial on 5 patients. Preclinical tests showed that image-based needle targeting can be accomplished with accuracy on the order of 1mm. Prostate biopsy can be accomplished with minimal TRUS pressure on the gland and submillimetric prostate deformations. All 5 clinical cases were successful with an average procedure time of 13 min and millimeter targeting accuracy. Hands-free TRUS operation, transrectal TRUS guided prostate biopsy with minimal prostate deformations, and the PCS based biopsy plan are novel methods. Robot-assisted prostate biopsy is safe and feasible. Accurate needle targeting has the potential to increase the detection of clinically significant prostate cancer.
IEEE transactions on bio-medical engineering. 2019 Jan 07 [Epub ahead of print]
Sunghwan Lim, Changhan Jun, Doyoung Chang, Doru Petrisor, Misop Han, Dan Stoianovici