Medical accelerators for use in radiotherapy

Radiation, as well as surgery, plays an important role in cancer treatment. Electron linear and heavy ion medical accelerators are outlined, focusing on their irradiation procedures. For electron linear accelerators, multifield, rotational, and conformation irradiation techniques are discussed in view of the limited absorption doses to the deep-seated lesions. Treatment using a particle accelerator is discussed, focusing on a Heavy Ion Medical Accelerator in Chiba (HIMAC) that is under construction at the National Institute of Radiological Sciences in Japan. (N.K.)