A fiducial-less tracking method for radiation therapy of liver tumors by diaphragm disparity analysis part 2: validation study by using clinical data

Objective Motion management must be considered in treating liver tumors. One effective approach is real-time tumor tracking, which can be performed by the CyberKnife® Robotic Radiosurgery System through the Synchrony® Respiratory Tracking System. It uses a combination of kV images, LED markers, an infrared camera, and surgically implanted fiducial markers to track tumors under the influence of respiration. However, the use of fiducial markers through an invasive procedure can lead to complications. In our previous simulation study, we were able to demonstrate the feasibility of our proposed fiducial-less tracking technique using a digital phantom under regular respiratory motion. The aim of this study is to further validate this innovative method by using a digital phantom data under the irregular respiratory cycles as well as clinical data from patients under the Cyberknife environment.