A new robotic needle insertion method to minimise attendant prostate motion

Area of Science:

• Medical imaging and interventional procedures
• Robotics in medicine
• Oncology and radiation therapy

Background:

• Needle insertion can cause significant tissue motion, particularly in the prostate.
• This motion poses challenges for procedures like MRI-guided prostate brachytherapy and biopsies.
• Minimizing prostate motion is critical for accurate radiation delivery in intensity-modulated radiotherapy.

Purpose of the Study:

• To evaluate a novel needle insertion technique (tapping) versus traditional pushing.
• To quantify the reduction in prostate motion achieved by the tapping method.
• To assess the potential of this technique for improving image-guided interventions.

Main Methods:

• Prostate motion was measured in 30 patients undergoing transperineal implantation of fiducial markers.
• Needles were inserted using both manual pushing (32 instances) and a prototype robotic tapping system (29 instances).
• Cranio-caudal prostate motion was recorded via ultrasound video and analyzed using SPSS.

Main Results:

• Mean prostate motion was 5.6mm (range 0.3-21.6mm) with the pushing method.
• Mean prostate motion was significantly reduced to 0.9mm (range 0-2.0mm) with the tapping method (p<0.001).
• A statistically significant difference (p<0.001) was observed between the two insertion techniques.

Conclusions:

• Tapping is a superior method for needle insertion, yielding substantially less prostate motion than pushing.
• This finding supports the development of robotic systems utilizing a tapping mechanism for MRI-guided prostate interventions.
• The reduced motion has direct implications for enhancing the precision and efficacy of prostate cancer treatments.