Evaluation of 99mTc- labeled Radiopharmaceuticals Quality Control Procedures in the Radiation and Isotopes Center of Khartoum.

Abstract

This study was conducted at the nuclear medicine department of the Radiation and Isotopes Center of Khartoum (RICK), during the period from 2010 to 2016. The main objective of the study was to study the situation of 99mTc – radiopharmaceuticals QC procedures in RICK. The data were collected from many experimental and observational procedures which were done for the first time, to the best of the researcher's knowledge. These procedures included measurements of radiation exposures and contamination rates at different areas of the department. All the measured radiation exposures in the different areas of the department were within the permissible limits, except the waiting room of the injected patients, in which the radiation exposure rates were high owing to the large number of patients and the narrow area. Physical inspection of 99mTc eluate appearance for color, particles size and turbidity was performed which revealed no abnormality in these variables. Measurement of remaining (unused) activities were performed on different elution yields, and revealed that the total unused activities from 13 elutions were 3999.4 mCi (57%) out of the total eluted activities (7008.7 mCi), 32% of the unused activities were prepared (mixed with the chemical agent) and 74% were unprepared. These unused activities constitute a radiation hazard, in addition to the economical aspect. The researcher measured the external radiation exposure emanating from a new generator, and the generator package surface contamination of two generators, and the tests showed no abnormal results. The measurements, as well, included the radiation doses received by some body organs during elution of generators, injection and imaging of patients. Pyrogenicity test on three mature rabbits was done, and revealed a total temperature increment by 0.9 C0 , which was an evidence of the presence of pyrogens within the tested radiopharmaceutical. The study also included the 99Mo breakthrough test which revealed that the amounts of molebdenum-99 within the eluate were within the internationally acceptable limits, and there was no justification to sacrifice the eluate of the first elution of each generator. The lack of personnel radiation monitoring devices, and the undetermined regular working hours of the staff members made the specification of accurate received doses very difficult, in spite of the attempts made by the researcher to estimate these doses, depending on assumptions. The study concluded that no regular 99mTc radiopharmaceuticals QC procedures were performed in the nuclear medicine department of RICK and that most of radiation doses in different areas were within the internationally permissible limits. The results and recommendations of the study may constitute a great benefit to the department, and a start point to design and implement a comprehensive program of QC procedures in this domain at daily, weekly, monthly and annual fashion. Future studies in this domain are encouraged.