Development and utilization of particle radiation accelerators for diagnosis and treatment of cancer

Fast neutrons and protons generated by accelerators which can be established in the hospital are effective in treating cancer. As it is possible to make a small-sized cyclotron generating fast neutrons by introduing ultra-transmission technique, the isocenters technique can be utilized. Since beam control of proton is easy, regional dose distribution can be changed according to the target volume, and diagnostic capacity of protons is excellent, synchrotron and synchrocyclotron were designed as a proton accelerator for medical treatment. Protons generated by synchrotron have a track of 53 cm and can be applied to CT, but a large-sized apparatus with a large floor is required. Protons generated by synchrocyclotron has track of 33 cm, and protons are generated easily by a single accelerator. It was clarified that short-lived RI could be produced and labelled by a small-sized cyclotron in the hospital. This made it possible to dynamically analyze sites where isotopes were metabolized and accumulated. Moreover, an analytical method of trace amounts of elements peculiar to a tumor bearing body by protons with low energy and alpha particles has been established and application of this method to qualitative diagnosis of cancer is attempted. (Tsunoda, M.)