Development of Radiopharmaceuticals in Japan

The total annual sales for radiopharmaceuticals in fiscal year of 1985 in Japan was 42.9 billion yen which was 6.4% increase from the previous year. 1. The in vivo sales share about 33%, 14.1 billion ten with the increase of 4.3% from the previous year. The increase rate of radiopharmaceuticals in Japan in these several years is getting slower. This is mainly due to lower growth rate in vitro area caused by the development of non-isotopic technology. Although the increase rate of in vivo radiopharmaceutical is not as in vitro, it steadily increases in these 10 years. Main radionuclides for in vivo use are Tc-99m, Xe-133, Ga-67 and Tl-201 which occupies more than 95% out of total radiopharmaceuticals. Figure 2 showed recent trend of Tc-99m usage. In 1985, 3,900 Ci were used as Mo-99 - Tc-99m generator and 1,000 Ci as Tc-99m solution. The Tc-99m totaled 4,900 Ci which is about 75% of total radiopharmaceuticals used in Japan, and is still increasing year by year. Another important radionuclide is Xe-133, and remarkably increased in these years. In 1985, 1,020 Ci of Xe-133, 360 Ci of Ga-67 and 220 Ci of Tl-201, have been used. As an alternative of Xe-133, Kr-81m has been used. Though the amount of Kr-81m used is about 17 Ci in 1985, its growth rate is more than 20% and is expected to increase. As for In-111, it decreased until 1982, but it began to increase because of its ideal characteristics to label with various antibodies through the chelating agent which will be discussed later