Research progress on image-guided localization and tracking in CyberKnife treatment of hepatocellular carcinoma

CyberKnife has the characteristics of good repeatability of radiotherapy target, high precision and less trauma. It is a stereotactic body radiation therapy system for real-time tracking of moving tumors during treatment. For intrahepatic tumors being highly affected by respiratory movements in treatment, CyberKnife provides precise positioning, planning, and treatment. This paper focuses on the treatment of hepatocellular carcinoma (HCC) using CyberKnife, and reviews as following: the structure and iteration of CyberKnife; image-tracking modes and their advantages and disadvantages; tracking modes of common fiducial markers and their optimization methods, the positioning problems after the implantation of fiducial markers.