Image-guided interventions have become a mainstay of cancer diagnosis and treatment. By image-guided we mean the use of medical imaging such as uoroscopy or computed tomography (CT) to carry out minimally invasive procedures. ese procedures can be done through percutaneous instrument placement (through the skin) or through the vasculature using catheterbased approaches. Navigation systems to assist the physician in more precisely completing image-guided interventions have also been introduced in recent years by commercial companies and are an active area of research. Since we focus on navigation systems for cancer interventions in this chapter, we will call this Navigated Image-Guided ermal Cancer erapy (NIGTCT).