Stochastic effects in a discrete RT model with critical behaviour

[摘要] The effects of radiation on a tissue (being it healthy or cancerous) are well described by current linear-quadratic (LQ) radiobiological model for low absorbed doses around the 2 Gy often used in clinical fractionation. However, experimental data show a disagreement between the predicted and the observed effect of large doses. The Sotolongo et al. (2011) radiobiological (SRB) model, derived from Tsallis nonextensive entropy, has shown a good agreement with experiments for high absorbed doses, where LQ overestimates the dose required for a required effect. Other studies have reported a crossover in LQ model where its effects are underestimated for large doses. In this paper we develop a mechanistic version of the SRB model and show that it can reproduce both behaviors with a minimum set of assumptions. We compare the results of our simulations with some data reported in the literature. We also trivially adapt this model to fractionated radiotherapy and, in particular, to hypofractionation for which we draw some conclusions.

[发布机构] Dept. Fisica Matematica y de Fluidos, UNED, Senda del Rey 9, Madrid; 28040, Spain^1;Fundacio ACE, Institut Catala de Neurociencies Aplicades, Barcelona; 08029, Spain^2

[效力级别] 数学

[关键词] Absorbed dose;Critical behaviour;Fractionated radiotherapy;Hypofractionation;Linear quadratic;Nonextensive entropy;Radiobiological modeling;Stochastic effects