Application state of radioisotopes for medical use

Application of unsealed radioisotopes as radiopharmaceuticals has been increasing year by year with the development of nuclear medicine. As for the radioisotopes for in vivo use which are internally administered and are detected by external scanning, the consumption of Tc-99 m drugs has increased rapidly. The sales of radiopharmaceuticals for in vivo use including 131I, etc. amounted to four billion Yen in 1977. The consumption of the isotopes used in vitro for radioimmunoassay has made more rapid increase, and the sales of radiopharmaceuticals for in vitro use amounted to seven billion Yen in 1977. Radiopharmaceuticals have been used in 1,134 institutes all over Japan in 1978. 534 among them have applied radiopharmaceuticals to both in vivo and in vitro uses. Radioactive wastes have been increasing with the application of these unsealed radiopharmaceuticals, and their disposal method should be examined as there is a limit in their storage. (Kobatake, H.)