With an incidence of over 19 million in 2020 [1], cancer is one of the leading causes of death. Radiotherapy (RT) has long been one of the most widely used and effective treatment options, which is required in over 60–70% of these cases [2]. However, since the ionizing radiation that is at the core of the treatment can also impose severe harm to patients and staff, safe and automated dose delivery is one of the key challenges of RT. Another interesting aspect is the localization of the target, which is typically deep inside the patient and not readily visible. It may also be subject to patient motion which has to be considered during treatment. Given the challenging environment, the need for automation, and the dynamics of patient motion, a number of systems based on robots and robotics methods have been proposed. The steady increase in the numbers of publications shown in Fig. 1 illustrates the growing interest in robotic systems in RT.
