Role of Microwave Accelerators in Cancer Treatment

Microwave accelerators have been playing an important role in the light against cancer for more than forty years. Most of the cancer radiation therapy (RT) machines are based on linear accelerators (Linacs). Recent RT machines have imaging capability in addition to the treatment function. This image-guided radiation therapy (IGRT) approach has been recently realized in several cancer treatment machines. Some of the IGRT machines use the accelerator as the source of X-ray for both treatment and imaging. This requirement imposes new demands on the accelerator designer. Linacs used for cancer RT normally require microwave power at S-band or X-band frequencies. These are produced by Klystrons or Magnetrons. In this paper we discuss general requirements of the medical accelerators and their manufacturing. One of the objectives of this paper is to motivate microwave and accelerator engineers to continue the research and development effort in microwave sources and accelerator technology to meet the demands of the new developments in radiation therapy.