Fusing MRI and ultrasound images can be complex and does not always work perfectly. If the tumor could be targeted with MRI, the extra step of fusion could be avoided. However, MRI machines make use of extremely strong magnets and metal instruments cannot be near the machine when it is turned on. This makes it impossible to use metal needles or machines with any metal components (including electrical wiring).
Researchers at Johns Hopkins, led by Dan Stoianovici, PhD, Director of the Urology Robotics Program, have developed a completely MRI-compatible robot to target the prostate and cancers within it. The robot makes use of pneumatic system composed of rubber and plastic tubing, screws and gears to manipulate a MRI-compatible needle to target the prostate. "The robotic device mounts on the MRI table alongside the patient. The physician selects a suspicious region that the MRI has shown, and the robot automatically guides the needle to target and presets the depth of insertion."
"To the best of our knowledge, this is the only robot approved by the FDA to operate in the MR environment in general, not only for the prostate."
The MR-bot (MRI-robot) has been approved by the Food and Drug Administration (FDA) and Insitutional Review Board (IRB) of Johns Hopkins for a clinical trial in humans. Urologists Mohamad Allaf, MD and Ashley Ross, MD, PhD, perform the biopsies. The first few cases indicate that robotic biopsy is safe and feasible.
With more precise imaging and techniques, urologists may continue to improve the precision of prostate biopsies. This work was awarded best paper of the Engineering and Urology Society of the American Urological Association.
Read more about the MrBOT at: http://urobotics.urology.jhu.edu/projects/MrBot/
Portions of this story were extracted from "First-Ever MRI Robot Targets Potential Cancer Sites for Biopsy" in Discovery: Volume XI, Winter 2015 by the Patrick C. Walsh Prostate Cancer Research Fund.