Internal microdosimetry of alpha-emitting radionuclides
Autor: | Balázs G. Madas, Wei Bo Li, Werner Hofmann, Brian W. Miller, Imre Balásházy, Werner Friedland, Manuel Bardiès |
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Rok vydání: | 2019 |
Předmět: |
Internal dosimetry
Biophysics chemistry.chemical_element Americium Microdosimetry Review Radiation Bone and Bones 030218 nuclear medicine & medical imaging Nuclear physics 03 medical and health sciences 0302 clinical medicine Specific energy Animals Humans Radiometry Lung Randomness General Environmental Science Physics Radioisotopes Radionuclide Alpha particle Alpha Particles Plutonium chemistry 030220 oncology & carcinogenesis Alpha-emitting radionuclides Internal Dosimetry Alpha-emitting Radionuclides |
Zdroj: | Radiation and Environmental Biophysics Radiat. Environ. Biophys. 59, 29–62 (2020) |
ISSN: | 1432-2099 |
Popis: | At the tissue level, energy deposition in cells is determined by the microdistribution of alpha-emitting radionuclides in relation to sensitive target cells. Furthermore, the highly localized energy deposition of alpha particle tracks and the limited range of alpha particles in tissue produce a highly inhomogeneous energy deposition in traversed cell nuclei. Thus, energy deposition in cell nuclei in a given tissue is characterized by the probability of alpha particle hits and, in the case of a hit, by the energy deposited there. In classical microdosimetry, the randomness of energy deposition in cellular sites is described by a stochastic quantity, the specific energy, which approximates the macroscopic dose for a sufficiently large number of energy deposition events. Typical examples of the alpha-emitting radionuclides in internal microdosimetry are radon progeny and plutonium in the lungs, plutonium and americium in bones, and radium in targeted radionuclide therapy. Several microdosimetric approaches have been proposed to relate specific energy distributions to radiobiological effects, such as hit-related concepts, LET and track length-based models, effect-specific interpretations of specific energy distributions, such as the dual radiation action theory or the hit-size effectiveness function, and finally track structure models. Since microdosimetry characterizes only the initial step of energy deposition, microdosimetric concepts are most successful in exposure situations where biological effects are dominated by energy deposition, but not by subsequently operating biological mechanisms. Indeed, the simulation of the combined action of physical and biological factors may eventually require the application of track structure models at the nanometer scale. |
Databáze: | OpenAIRE |
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