Radiation risk for employees involved in the validation of methods to control radiochemical impurity in technetium-99m radiopharmaceuticals
Authors:   tate Research Center – Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Malysheva A.O. , Lyamtseva E.A. ,   tate Research Center – Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Taratonenkova N.A. ,   tate Research Center – Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Lunev A.S. ,   tate Research Center – Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency
Published: December 2024

The validation of methods to control radiochemical impurities content in radiopharmaceuticals (RPh) has some features and differs from the established analytical methods for control of radiochemical impurities in drugs free of radionuclides. The article presents the results of the validation procedure for determination of radiochemical impurities content in 99mTс radiopharmaceuticals, such as “Pyrphotech,99mTс”, “Technephyte,99mTс”, “Tehnephore,99mTс”, “Phosphotech,99mTс”, “Rezoscan,99mTс” and “Medroscan,99mTс” at performing the “Specificity” and “Precision” (“Repeatability and “Intermediate precision”) tests. The selectivity of the chromatographic determination of sodium pertechnetate and hydrolyzed reduced technetium-99m has been proven. Coefficients of variation were 5.0% and the relative error of the methods does not exceed 11.5%. The calculated values of the Student's t-test for two samples for each chromatographic system for each radiopharmaceutical in the "Intermediate precision" tests did not exceed the table value of the Student's test, equal to 3.17 at the confidence probability of 99%. This indicates that there are no differences between the results obtained in each chromatographic system and confirms the validation of the methods for precision. It has been shown that performing the listed tests when validation at the minimum volume activity of RPh allowed in regulatory documents (185 MBq/ml) is associated with significant radiation burden on the personnel of the quality control laboratory. The equivalent dose to an employee's eye lens can be up to 6.0 mSv, and to the fingertips – up to 1,310 mSv, which is almost 2.6 times the limit for the established annual dose to the fingertips. Thus, we can conclude that it is impossible to perform all tests in full volume by one employee in compliance with the dose limits established by NRB-99/2009, OSPORB-99/2010. When health care providers perform these tests, the risk of radiation exposure to the employees will increase several times because performing the listed tests when validation at the minimum volume activity of RPh allowed in regulatory documents (185 MBq/ml) is associated with significant radiation burden on the employees of the quality control laboratory. The equivalent dose to an employee's eye lens may be up to 6.0 mSv, and to the fingertips – up to 1,310 mSv, it is almost 2.6 times exceeds the limit for the established annual dose to the fingertips. Thus, we can conclude that it is impossible to perform all tests in full volume by one employee in compliance with the dose limits established by NRB-99/2009, OSPORB-99/2010. When performing these tests in health care providers, the risk of employees exposure to radiation will increase several times because for radiopharmaceuticals preparation the volume activity necessary for diagnostic procedures is used.