On the Equivalent Dose for Auger Electron Emitters

• Published in: Radiation research Vol. 134; no. 1; pp. 71 - 78
• Main Authors: Howell, Roger W., Narra, Venkat R., Kandula S. R. Sastry, Rao, Dandamudi V.
• Format: Journal Article
• Language: English
• Published: Oak Brook, Il Academic Press, Inc 01-04-1993; Radiation Research Society
• Subjects: Animals; Applied radiobiology (equipment, dosimetry...); Augers; Biological and medical sciences; Biological effects of radiation; Cell nucleus; Cell Survival - radiation effects; Dose-Response Relationship, Radiation; Electrons; Fundamental and applied biological sciences. Psychology; Idoxuridine; Iodine Radioisotopes; Iodobenzenes; Male; Mice; Radiation dosage; Radioactive decay; Radionuclides; Radiotherapy; Relative biological effectiveness; Solar X rays; Sperm Head - radiation effects; Testes; Tissues, organs and organisms biophysics; Spermatogenesis; Mortality; Rodentia; Relative biological effectiveness; Biophysics; Dose equivalent; Radioisotope; Experimental study; Linear energy transfer; Vertebrata; Ionizing irradiation; Mammalia; Radiobiology; Mouse; Animal; Radiation injury; Auger emission
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3578503

Radionuclides that emit Auger electrons are widely used in nuclear medicine (e.g., ^{99{\rm m}}{\rm Tc},\ {}^{123}{\rm I},\ {}^{201}{\rm Tl}$) and biomedical research (e.g., ^{51}{\rm Cr},\ {}^{125}{\rm I}$), and they are present in the environment (e.g., ^{40}{\rm K},\ {}^{55}{\rm Fe}$). Depending on the subcellular distribution of the radionuclide, the biological effects caused by tissue-incorporated Auger emitters can be as severe as those from high-LET α particles. However, the recently adopted recommendations of the International Commission on Radiological Protection (ICRP) provide no guidance with regard to calculating the equivalent dose for these radionuclides. The present work, using spermatogenesis in mouse testis as the experimental model, shows that the lethality of the prolific Auger emitter 125 I is linearly dependent on the fraction of the radioactivity in the organ that is bound to DNA. This suggests that the equivalent dose for Auger emitters may have a similar linear dependence. Accordingly, a formalism for calculating the equivalent dose for Auger emitters is advanced within the ICRP framework.