Performance of Tc-99m Generators in Terms of Molybdenum Contents Measured in NORIN Nawabshah, Pakistan (5 years’ Experience)

Abstract

Technetium-99m is extensively used radiopharmaceutical in nuclear medicine centres throughout the world because of its optimum half-life and photon energy. 99mTc is obtained from 99mTc-99Mo generator. 99Mo contents may appear in 99mTc elutes due to certain reasons. These contents are needed to be checked before injecting it to the patient. In Pakistan, these generators are manufactured in Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad, who names its generators as PAKGEN. 99mTc is eluted on site from generator and used with pharmaceutical kit. Eluted 99mTc may contain some impurities which need to be contained within predefined allowed limits. One of the impurities is molybdenum. For molybdenum, there are two protocols being used worldwide. European pharmacopeia declares the allowed activity of Molly in 99mTc elute to be less than 1 µCi of 99Mo for every mCi of 99mTc, while American pharmacopeia defines it to be less than 0.15 µCi/mCi. PINSTECH is using European standards for its PAKGEN generators. NORIN is using 99mTc-99Mo generators since 2012, purchased from PINSTECH Islamabad. A total of 216 generators were purchased till date. Current study is an assessment of Molly assay tests performed on the first elution of every generators before its administration to patients for diagnostic procedures. Results of these tests are compared with both European and American pharmacopeia standards and found out to be well within both limits. Only 1.4% of total 216 generators were found to be out of the limit of 0.15 µCi/mCi (being practiced in our medical centre), while no one exceeded the limit of 1 µCi/mCi (being implemented by the manufacturer of generators). It is concluded that PAKGEN generators are reliable source of technetium-99m in terms of molybdenum contents.