PENENTUAN KEMURNIAN RADIONUKLIDA DARI PRODUK GENERATOR Mo-99/Tc-99m NON-FISI MENGGUNAKAN SPEKTROMETER GAMMA

Abstract

The medical radionuclide technetium-99m (Tc-99m) is the type of radionuclide that is most widely used in diagnostic processes in the world of nuclear medicine. This is related to its characteristic of having a half-life of 6 hours and releasing a single gamma energy (E ) of 140 keV. Tc-99m is a product of the Mo-99/ Tc-99m generator and is a decay child of molybdenum-99 (Mo-99) which has a half-life of 66 hours. The Mo-99  radionuclide can be produced via a neutron activation reaction which requires the non-fission natural target molybdenum trioxide (MoO3) as a target in a nuclear reactor, so it is called a non-fission Mo-99/Tc-99m generator. The aim of this research is to determine the purity value of the Tc-99m product from the non-fission Mo-99/Tc-99m generator using the gamma spectrometer method. This is done by analyzing the energy and efficiency calibration of the gamma spectrometer using a liquid standard source (Liquid Source) of a mixture of Ba-133  and Eu-152, and a point standard source (Point Source) of Eu-152, according to the geometry for the measurements of Mo-99 breakthrough and Tc-99m products respectively for each three-generator elution process. The neutron activation process of natural molybdenum (MoO3) was carried out in the nuclear reactor G.A. Siwabessy, Indonesia. The purity of the Tc-99m  product radionuclide from the non-fission Mo-99/Tc-99m generator was obtained at 99.999% for each elution while the largest Mo-99 breakthrough was 0,0018 µCi Mo-99/mCi Tc-99m and the lowest was 1,04 x 10-4 µCi Mo-99/mCi Tc-99m. The Mo-99 breakthrough results obtained were below the value of 0,15 µCi Mo-99/mCi Tc-99m set by the US Pharmacopoeia, so the resulting product of Tc-99m was good, and showed that the product could be used for the labeling process to become a radiopharmaceutical. This radionuclide purity measurement method can be used to determine quality control parameters for non-fission Mo-99/Tc-99m generator products.