Dr Joost Nuyttens speaks about Cyberknife, explaining which cancers can be treated with this technology and how patients are selected. The benefits include the relatively small number of hospital visits required and the ability to track the tumour, ensuring that healthy tissue is not irradiated even if the patient moves. Dr Nuyttens discusses the option of using either Cyberknife or robotic surgery to treat prostate cancer and the possibility of clinical trials to establish which of the two is most effective.