Medical use of radiation and particle accelerators

Recently, medical use of radiation has progressed markedly with the application of newly developed techniques and modalities. And the progress of radiation diagnosis too, has felt the impact of imaging techniques since the introduction of X-ray computerized tomography (X-ray CT). In radiation therapy, efforts have been concentrated on studies to improve local control rates of radioresistant cancers and locally advanced cancers, which remained a problem even after the introduction of megavoltage radiation therapy machines. Particle radiation, characterized by an excellent dose distribution as well as the features of high LET radiation, has been introduced in to clinical research for use in radiation therapy. Other studies with particle radiation suggests that the short lived radioisotopes produced by accelerators will open up a new era for nuclear medicine. This paper looks at the present status and some of the future problems in the medical use of radiation and radioisotopes in Japan.