Image‐guided robots for low dose rate prostate brachytherapy: Perspectives on safety in design and use

Abstract

Background Image‐guided brachytherapy (BT) robots can be used to assist urologists during seed implantation, thereby improving therapeutic effects. However, safety issues must be considered in the design of such robots, including their structure, mechanical movements, function, materials and actuators. Previous reviews focused on image‐guided prostate BT robot technology (e.g., imaging and robot navigation technology and robot system introduction); however, this review is the first time that safety issues have been investigated as part of a study on low‐dose‐rate (LDR) prostate BT robots. Methods Multiple electronic databases were searched for LDR prostate BT robot articles published during the last 24 years (1996–2020), with a particular focus on two aspects of robots: safety in design and use. Results We retrieved a total of 26 LDR prostate BT robots. BT robots were divided into ultrasound, computed tomography, magnetic resonance imaging and fusion‐guided systems. The conditions associated with each system were then analysed to develop a set of requirements for the safety of prostate BT robots. Recommendations are also provided for future BT robot development. Conclusions The transrectal approach for prostate seed implantation is safer than the traditional transperineal approach. Research into the control of a steerable needle by the urologists and robot, the needle deflection model, and robotic automated needle changing and seed injection equipment should be pursued in a future study.

Robotic Systems in Radiotherapy and Radiosurgery

“…One general challenge in robotic BT is the safety of the system. Since the implantation of radioactive seeds is an invasive procedure, particular care has to be taken in order to verify the system's safe operation, compare Dai et al for an overview of recent methods [80].…”

A needle deflection model with operating condition optimization for corrective force‐based needle guidance during transrectal prostate brachytherapy

“…Precise needle placement, for the positioning of radioactive seeds, is one of the most challenging components of LDR prostate BT, as it directly affects dose delivery and treatment outcomes. 4 Even small seed positioning errors (>6 mm) 8 can result in unsatisfactory dose distribution and insufficient tumour coverage, often caused by needle deflection. As shown in Figure 2, BT needles are commonly made of a nickel-titanium alloy and are designed to be semi-flexible.…”

“…Once the desired depth is reached, the seeds are deposited by extruding them from the needle as it is withdrawn. 4,5 Clinical practice involves two needle insertion routes for prostate BT, transperineal (TP) and transrectal (TR), as shown in Figure 1. Patients who undergo TP prostate BT, which is commonly used in clinical practice, require general anaesthesia or epidural anaesthesia.…”

“…LDR‐BT involves loading a needle with rice‐sized radioactive seeds for insertion into the prostate. Once the desired depth is reached, the seeds are deposited by extruding them from the needle as it is withdrawn 4,5 …”

Design and Experimental Setup of a Robotic Medical Instrument for Brachytherapy in Non-Resectable Liver Tumors

“…Dai et al [ 12 ] divides the brachytherapy robotic system into four categories with respect to the imaging method used: ultrasound (US)-guided systems [ 13 , 14 , 15 , 16 ], MRI-guided systems [ 17 , 18 , 19 ], CT-guided systems [ 20 , 21 , 22 , 23 ] and additional image-guided systems [ 24 , 25 , 26 , 27 ]. Lin et al [ 28 ] proposes a multi-DoF (Degrees of Freedom) robotic system for liver brachytherapy.…”