CT-guided percutaneous interventions: Improving needle placement accuracy for lung and liver procedures

Accurate needle placement inside the body is critical in several medical procedures. Generally, this is done by hand (freehand), using a CT scanner to verify the needle’s position. This PhD research focussed on whether the use of a robot to aim the needle will result in increased needle positioning accuracy. The robotic approach is validated in CT-guided liver tumor ablation. With tumor ablation, a needle is inserted through the skin into the tumor in order to kill the tumor using heat. This minimally invasive approach is often a good alternative to surgery. Accurate needle positioning inside the tumor is crucial because positioning inaccuracy may result in an incomplete ablation and incomplete ablations require additional treatment. This research has shown that with the use of the robot the needle was placed in an adequate position inside the tumor every time in one try; with the freehand method, this generally required two attempts. The resulting positioning error was smaller for the robot approach, too, though mostly for difficult-to-reach tumors. This means that in the near future, tumors that are too difficult to reach with the freehand approach and would have to be treated with surgery can be treated with minimally invasive ablation instead, using the robot. Also, the reliability of liver tumor ablation was investigated for different kinds of liver tumors. Finally, Wout Heerink developed a method to accurately track patient breathing, in order to be able to use the robot for lung tumors, too