Robotics for percutaneous approaches

Why robotics in IR matter

In surgery, the famous da Vinci robot has been in use since the 1990s, and the use of robots is well-established in this field. However, the use of robots in interventional radiology (IR) is still limited, even though they can be valuable tools. Especially in IR, it is important to reach the treated lesion as precisely as possible and to use as little radiation as possible when performing percutaneous interventions with computed tomography (CT). Ideally, the interventions should be performed in a time-saving manner. Robots are particularly useful when treating difficult-to-access lesions, especially those close to blood vessels, when using multiple needles to achieve a large ablation area, or when working at a difficult angle to a target (out-of-plane).

Most robots available on the interventional oncology market are for percutaneous applications, i.e., needle guidance robots. They assist in positioning the needle and determining the angle and depth of needle insertion, while the actual insertion is usually performed by the interventionalist. This preserves the haptic experience and enables early detection of incorrect needle positioning, such as hitting bones during insertion.

So, what’s currently out there?

There are a number of systems on the market today; most are designed for use with CT scanners. The main differences between the available systems are their size and the ancillary modules they include. However, one of the most significant differences is the way in which the robotic device is registered with the CT scanner, whether it is on a plate on the floor near the CT scanner, mounted on the CT table, or partially mounted on the patient. The newer models are also equipped with a stereotactic module. Some also have special modules to monitor the patient’s breathing. The latter is particularly important when performing biopsies or percutaneous procedures without anaesthesia, as it allows the appropriate respiratory phase to be determined for inserting the needle.

Show me the evidence!

The majority of the studies involving the use of robotic systems in IR have focused on liver procedures. These studies have demonstrated that the use of robotics in microwave ablation (MWA), irreversible electroporation (IRE) or radiofrequency ablation (RFA) is safe and highly accurate [1-4]. Additionally, the number of needle adjustments is reduced in robot-assisted procedures, and radiation exposure is lower when a robotic system is used [2, 4-6].

It is not only in liver procedures that robotic systems are being used. For instance, a study demonstrated the successful use of a robot in IRE of the pancreatic head with improved accuracy and reduced procedure time compared to the standard procedure [7]. Another successful application of a robotic system with respiration control was demonstrated in biopsies of the liver, kidney, pancreas and lymph nodes, where needle placement was successful on the first attempt [8].

The studies mentioned above show that the use of robots is safe, and their technical efficacy is equal to or even higher than standard procedures. The success rate of ablation and the rate of complications are similar or equivalent in the robotic-assisted group compared to the standard treatment. However, when looking at procedure times, the picture is less clear. Although the actual needle placement is quicker with the help of robots, the pre-procedure planning takes time. Thus, overall procedure times are comparable, with only a few studies showing significant benefits [4, 7, 9]. Nonetheless, with the use of robotic systems for out-of-plane procedures, substantial time savings can be observed [9, 10].

Using robotics to perform IR procedures has several advantages, including improved precision and accuracy, as well as reduced radiation exposure for both the interventionalist and the patient. Overall, using robotics to perform percutaneous interventional radiology procedures is a promising development that has the potential to improve patient outcomes and safety.