放射性医薬品のための¹²³Iの製造

抄録

  Nihon Medi-Physics Co., Ltd. has been producing ¹²³I with its cyclotrons since 1975. During the years, we have tried several production methods by ¹²²Te (d,n), ¹²⁴Te (p, 2n), ¹²⁷I (p, 5n) and ¹²⁴Xe (p, 2n) reaction. As a result, we have reached a conclusion that the indirect production method using ¹²³Xe-¹²³I precursor system enables the supply of high purity ¹²³I, which is essential for the nuclear medicine studies with low radiation exposure as well as clear image, and high ¹²³I yield for the supply of Na ¹²³I capsule and ¹²³I compounds (such as Perfusamine, an imaging agent for cerebral blood flow study).

  The amount of ¹²³I used annually in Japan exceeded that of ¹³¹I in 1987. If the cyclotron with high external beam current is used, the production capability of ¹²³I will be high enough for the existing ¹²³I radiopharmaceuticals as well as for new ones.