The Auger electron effect in radiation dosimetry.

The Auger electron effect is of importance in radiation protection related to work in radiobiology, radiophysics, and nuclear medicine. Radionuclides that emit Auger electrons are widely used in nuclear medicine (99mTc, 123I, and 201Tl) and in biomedical research (51Cr and 125I). They are also present in the environment (40K). Therefore, calculation of the absorbed dose and equivalent dose to tissues from these incorporated radionuclides is important for risk assessment. Depending on the subcellular distribution of the radionuclide, the biological effects caused by cell-incorporated Auger emitters can be as severe as those from high-linear energy transfer (LET) alpha particles. However, the recently adopted recommendations of the International Commission on Radiological Protection in Publication No. 60 do not provide guidance on calculating the equivalent dose for these radionuclides. A better understanding of the effects of Auger electrons is required to estimate the equivalent doses, and further research in this field is appropriate. There are good reasons to consider the Auger electron effect not only in medical radiation protection of patients but also in the context of annual limits of intake for workers and the public.