Computed tomography (CT) fluoroscopy is a useful imaging modality for guiding various interventional procedures (e.g., ablation, biopsy, and drainage). However, radiation exposure is a major disadvantage of CT fluoroscopy guidance. Even if a physician uses 17-cm forceps, radiation exposure to their hand is 7.0 µGy/s (120 kV; 30 mA). The average activation time for CT fluoroscopy in a lung biopsy has been reported to be approximately 90 s. It is expected that the activation time would be longer for more complex procedures such as ablation for large tumors. Therefore, radiation exposure during CT fluoroscopy is a serious concern for physicians.
Robotic surgery, which is the preferred surgical method for 80% of prostate cancer surgeries in the United States, has been shown to reduce procedural complications. We hypothesized that robotic technology might be more easily applied to CT-guided interventions. If physicians performed CT-guided interventions using a robot that they controlled from a location far from the CT gantry, radiation exposure to physicians could be minimized. However, issues such as metal artifacts and the limited workspace may hinder the development of a robot for CT-guided interventions. More specifically, the robot must be constructed of non-metal materials and it must fit in a small space within the CT gantry. Despite these limitations, we have developed a prototype model of the robot.
The prototype has 5 degrees of freedom and can be remotely operated with a joystick controller. Phantom experiments using the prototype showed no radiation exposure to the operating physician during the procedure. In this article, we will provide an overview of the development of this prototype model, present the limitations of the prototype, and discuss future prospects.