A system for MRI‐guided transperineal delivery of needles to the prostate for focal therapy

Abstract

A system for delivering needles to a patient's prostate for focal therapy within the bore of an MRI scanner has been developed. Results from needle insertion tests in phantoms suggest that the system has the potential to provide accurate delivery of focal therapy to prostate tumors of the smallest clinically significant size. Initial tests in two patients showed that needle deflection was larger than in phantoms, but methods of manually compensating for this effect were employed and needles were delivered to treatment sites with sufficient accuracy to deliver effective treatment. In addition, the treatment was delivered in less time than with a fixed grid template or freehand insertions. Despite this success, methods of reducing needle deflection are needed in order to fully utilize the potential of this system, and further reduce total procedure time.

MR Safe Robot, FDA Clearance, Safety and Feasibility of Prostate Biopsy Clinical Trial

“…A problem that many others also confronted [20, 47, 50, 51] is that needle deflection errors can be sizeable. In our preclinical experiments where accuracy was good, we used symmetric point (diamond) needles.…”

“…As such, initial devices developed for direct MRI guided procedures were manually operated [18–20]. These have the merit of bringing the procedure first to clinical trials.…”

“…Few devices that reached clinical trial stages showed that direct MRI guided procedures are feasible [20, 34, 35, 37], within certain limitations.…”

In-bore MRI interventions

“…Much of this increased time is from repeatedly moving the patient out of the scanner to enable access to the needle, followed by repeat imaging. Some investigators have therefore looked at MR compatible robotic devices via rectal [32], gluteal [33] and perineal approaches [ 35,36] recently described an MR compatible mechatronic system for transperineal needle guidance ( Fig. 1).…”

Porphysome nanoparticles: Tailoring treatments with nature’s pigments

“…Photothermal therapy (PTT) has spatial control, similar to PDT, and acts independently of molecular oxygen concentration, and so performs better under hypoxic conditions [30]. Recent advances in interstitial laser fibers, coupled with a relatively large radius of heat diffusion, have allowed PTT to even be used in deep seated tissues [31,32]. PTT also causes thermoelastic expansion of water, which generates high frequency sound waves that can be detected with an ultrasound transducer.…”