Abstract
Background
Technitium-99m (99mTc) is a widely used radioisotope for the diagnostic procedures in nuclear medicine. The radioisotope is eluted from 99Mo/99mTc generator. Ideally there should be no Molybdenum-99 (99Mo) or any other contamination; however, sometimes traces of 99Mo are co-eluted from the generator. This impurity interferes labeling of 99mTc with pharmaceuticals result in poor quality radiopharmaceutical and unnecessary exposure to patients. The purpose of this study is to assess the contamination level of 99Mo in the eluted activity of 99mTc used for the diagnostic procedures at Swat Institute of Nuclear Medicine, Oncology and Radiotherapy (SINOR), Swat Pakistan. Also the purpose is to check the integrity of the generators being transported by road, and it is a part of quality audit of PAKGEN 99Mo/99mTc generators.
Methods
The data was collected for 166-PAKGEN 99Mo/99mTc generators used over 6 years at SINOR. The generators were procured from Isotope Production Division (IPD), Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad, Pakistan. The 99Mo impurity concentration was measured for each elution with dose calibrator (Capintech Inc. CRC-25R) and canister.
Results
Results for most of the generators (99.4%) were within the permissible limit (0.15 μCi of 99Mo/mCi of 99mTc) as per Pakistan Nuclear Regulatory Authority (PNRA), Nuclear Regulatory Commission (NRC), and other regulatory authorities. Only one generator (0.6%) had the values out of range.
Conclusion
99Mo breakthrough concentration for most of the generators was within permissible range which shows integrity of 99Mo/99mTc PAKGEN generators and approves the quality of locally prepared 99Mo/99mTc PAKGEN generators. The study replicates excellent manufacturing and quality control of PAKGEN generators which offers a confirmation of safe medical practices.

Key words: Molybdenum Concentration,99Mo/99mTc generator, Nuclear medicine, Image quality.