Yu Zhou, Abstract Co-Author: Nothing to Disclose

William Henry Moore MD, Presenter: Research grant, EDDA Technology, Inc

Kaarvannan Thiruvalluvan, Abstract Co-Author: Nothing to Disclose

Lukasz Krzeminski, Abstract Co-Author: Nothing to Disclose

Jerome Liang PhD, Abstract Co-Author: Nothing to Disclose

Josh Xu, Abstract Co-Author: Nothing to Disclose

To evaluate the potential use of a robotic system for needle biopsy of small nodules while the nodules are in motion.  

A prototype robotic needle manipulator was created to allow for the robot to control with six degrees of freedom the path of a standard biopsy needle. The needle grasper was made of synthetic non-metal material to facilitate use in computed tomography (CT). The motion of the lung nodule and other relevant internal structures at relaxed patient respiration was obtained from radiation therapy planning studies which utilized respiratory gating software. Based on the respiratory motion model, the optimal needle placement path was planned, and the needle placement was controlled using visual tracking from a fiducial marker. The phantom was constructed using soft-tissue equivalent with a pea at the center of the phantom. The motion path was programmed into a three dimensional motion stage and the robot was allowed to target the lesion from multiple different starting points. Three different lung nodule motion paths with varying nodule speed were programmed into the motion stage. 150 different needle paths were planned from different directions relative to the nodule paths, using an 18-gauge co-axial needle set. The final location of the tip of the needle was documented and the degree variance from the center was recorded.  

The needle hit the target in 100% of the tests. The mean error from the center of the lesion was 0.4 mm with a standard deviation <0.1mm.

The results show that the robotic needle placement technique is promising for accurately biopsying nodules under respiratory motion. Given the extremely high accuracy and precision reported we would expect to be able to biopsy very small lesions reproducibly and reliably.

This system could allow for more wide spread ability to biopsy extremely small nodules in patients whom would normally not be able to tolerate these procedures.  

Zhou, Y, Moore, W, Thiruvalluvan, K, Krzeminski, L, Liang, J, Xu, J, Robotic Controlled Needle Biopsy of Nodules with Respiratory Motion: Phantom Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015282.html