Keywords: low dose definition, computer simulation, multi random detector, MRD, photon beam, energy deposited, low radiation, radiobiology
The definition of low doses and their importance in radiobiology
The aim of this work is to introduce a new dosimetric approach that is expected to contribute to characterising and distinguishing low, intermediate and high dose ranges. The emphasis will be on the low dose range, owing to the importance of the biological effects at low doses. A Monte Carlo code was used to simulate the energy degradation of photons in water, where the coherent and incoherent scattering were sampled from the Thompson and Klein-Nishina cross-sections corrected by the form factor and the incoherent scattering function, respectively. For the photoelectric effect, the kerma approximation was used, meaning that the simulation of the interactions of photons provides the initial spectra of the secondary electrons that cause damages at the cellular and intracellular levels. A new scoring method was proposed that allowed multiscale analysis of the energy deposited by radiation, inspired by the basic definition of an absorbed dose. Data for analysis were obtained from the simulation of a photon beam with extremely low dose values in a water phantom. Implications of the results in radiobiological studies are discussed.