Proffered Presentations Archive

UK & Ireland Prostate Brachytherapy Conference 2024

Abstract number 23 

MRI-guided Needle Placement Robot for Prostate Brachytherapy 

Taimur Shah
Imperial College London 

Akram Gholami, Neel Sancheti, Sreeja Vangapelli, Paul Brathwaite, Aleksandar Nacev
Promaxo Inc. 

Purpose: Brachytherapy aims to deliver a precise and targeted dose of radiation directly to the cancerous tissue while minimizing exposure to surrounding healthy tissues [1]. Accurate seed placement ensures that the radiation reaches the intended area, maximizing its effectiveness in treating the tumor [2]. Combining low-field Magnetic Resonance Imaging (MRI) with brachytherapy can enhance the targeting accuracy by providing detailed anatomical information during seed placement. This is particularly important for ensuring that the radioactive sources are precisely positioned within and around the tumor or the target area. This study introduces an innovative MRI-safe needle guidance system integrated with the single-sided low-field Promaxo MRI system (Promaxo Inc., Oakland, California, United States). 

Methods: The needle guidance system, constructed from MRI-safe materials and featuring 5 degrees of freedom (DOF), is compact and utilizes pneumatic stepper motors for actuation. The system facilitates needle insertion from various angles by employing a spherical parallel mechanism. Following angulation, a translation screw is employed to insert needles or cannulas at different depths. 

Results: To assess its performance, the system underwent evaluation using a multi-modality prostate phantom model that mimics the human prostate and surrounding structures (Yezitronix Group Inc. Automation & Control Industries Inc.). In a benchtop experiment, needle placement accuracy was verified by piercing the phantom along a vertical line spaced at equal depth and then comparing the achieved distances with the distance between air tracks in Computed Tomography (CT) scan images of the phantom. The experimental results reveal an absolute error (mean ± SD) of 0.75±0.73 mm on the vertical line and 0.24±0.14 mm in depth. 

Conclusion: These preliminary experimental findings suggest the potential for precise robotic manipulation during brachytherapy procedures, offering a pathway to reduce the likelihood of human errors in procedures potentially improving patient outcomes.

References: 

1. Mohd Khairi, N. F. Z. ., Roszaini, N. F. ., & Othman, S. A.. Principles and Techniques in Handling Brachytherapy – A Short Review. Journal of Advanced Industrial Technology and Application, (2023), 4(1), 75-79 
2. Dhaliwal S. S., et al., Review of Clinical and Technological Consideration for MRI-Guided Robotic Prostate Brachytherapy, IEEE Transactions on Medical Robotics and Bionics, (2021) Aug., 3(3), 583-605