The radio-biological bystander effect as a non-linear diffusive phenomenon


The radiation-induced bystander effect (RIBE) is a phenomenon in which cells undergo genetic damage without having been directly irradiated by an external radiation source. In current literature, it is often modeled via Monte Carlo simulations with the standard Brownian motion as the underlying mode of diffusion. In this study, we replace the standard Brownian motion with the fractional Brownian motion (fBm) and compare it with previous experimental data. We note that the ensemble probability of irradiation is slightly higher in the subdiffusive regime as compared to the standard Brownian motion, which tends to underestimate it. Furthermore, the uniformity of irradiation is preserved in the subdiffusive regime. For these reasons, we conclude that the radio-biological bystander effect is more appropriately examined in the subdiffusive regime (H < 1/2).