XACT is developing a 5 degrees-of-freedom needle steering and insertion system comprised of a patient-mounted robot, a control unit connected to the CT and to the robot, and a workstation for procedure planning and observation. The system allows the interventional radiologist to easily plan the procedure and allow the robot to perform the needle insertion and steering under the radiologists’ control with unparalleled accuracy, while safely monitoring the progress from the work station in the control room. The XACT system is the first system to actively compensate for breathing and patient movement during the procedure allowing for fast, accurate and safe performance of needle insertion to the desired target. Real-time closed loop control coupled with the ability to complex angulation 3D trajectories, mean that any deviation from the original planned pathway can be immediately detected and corrected without the need for needle reinsertion or patient repositioning. The XACT system is expected to significantly reduce the learning curve for interventional radiologists to perform complex needle trajectories and to successfully reach small targets.