Open AccessOn calculation of the average linear energy transfer for radiobiological modelling
Author(s) -
Oleg N Vassiliev
Publication year - 2020
Publication title -
biomedical physics and engineering express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.333
H-Index - 16
ISSN - 2057-1976
DOI - 10.1088/2057-1976/abc967
Subject(s) - photon , fluence , monte carlo method , linear energy transfer , computational physics , ionization , statistical physics , physics , energy (signal processing) , radiation , electron , energy spectrum , mathematics , nuclear physics , statistics , optics , irradiation , quantum mechanics , ion
Applying the concept of linear energy transfer (LET) to modeling of biological effects of charged particles usually involves calculation of the average LET. To calculate this, the energy distribution of particles is characterized by either the source spectrum or fluence spectrum. Also, the average can be frequency-or dose-weighted. This makes four methods of calculating the average LET, each producing a different number. The purpose of this note is to describe which of these four methods is best suited for radiobiological modelling. We focused on data for photons (x-rays and gamma radiation) because in this case differences in the four averaging methods are most pronounced. However, our conclusions are equally applicable to photons and hadrons. We based our arguments on recently emerged Monte Carlo data that fully account for transport of electrons down to very low energies comparable to the ionization potential of water. We concluded that the frequency average LET calculated using the fluence spectrum has better predictive power than does that calculated using any of the other three options. This optimal method is not new but is different from those currently dominating research in this area.