First-Ever MRI Robot Targets Potential Cancer Sites for Biopsy
Here’s a challenge: MRI is getting really good at imaging localized prostate cancer, and although prostate biopsies have traditionally been done using another form of imaging, transrectal ultrasound, there are now ways to “fuse” these two technologies in real time, for a more comprehensive picture of the prostate while a biopsy is under way. But the two forms of technology don’t always go together perfectly, and sometimes this can make it difficult for the urologist to target with the ultrasound-guided biopsy needle the suspicious lesions that the MRI has picked up. Another problem: Because MRI requires that the patient lie inside a doughnut-shaped machine, the biopsy must be done using a special de vice. Also, there can be no electricity inside the MRI room.
Dan Stoianovici, Ph.D., Director of the Johns Hopkins Urology Robotics Program and Laboratory, has overcome these obstacles and developed a pneumaticdriven robot that has absolutely no metal — metal and the strong magnetic field inside the MRI wouldn’t work well together — and is made of plas tic, ceramic, glass, and rubber, “all non-magnetic and non-conducting materials,” he notes. “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 the target and presets the depth of insertion.”
The device has been approved and declared MRI-safe by the Food and Drug Administration and by the Johns Hopkins Internal Review Board, and a clinical study has just started. Urologists including Mohamad Allaf and Ashley Ross perform the biopsies. “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 pr ostate,” says Stoianovici.
“The first clinical cases suggest that robotic biopsy is safe and feasible.” With more precise knowledge of suspicious areas to investigate, urologists may be able to make biopsies even more accurate at determining the true picture of cancer within the pr ostate. This technology may also help radiation oncologists achieve more precise implantation of radiation seeds in brachytherapy. Stoianovici presented this work at the annual meeting of the American Urological Association, where it was awarded Best Paper of the Engineering and Urology Society. Other authors of the paper include Chunwoo Kim, Changhan Jun, Doru Petrisor, Katarzyna Macura, Ross, and Allaf.