X-rays used in medical imaging are ionizing radiations and may induce cancers, an effect known as stochastic and cumulative. Based on studies on nuclear bomb survivors in Japan, the carcinogenic effect of ionizing radiation is definite with exposures above 100 mSv (RERF 2022; National Research Council 2006). Below this threshold, although no direct effect of radiations as used by medical imaging for the chest can be observed and measured, it is considered that repeated individual exposures induce cumulative risks that are proportional to the dose. Thus, risks can be extrapolated from high doses at which increased cancer incidence has been observed to lower doses as used in medical imaging. This extrapolation from high to low doses used as a rule by all authorities around the world is known as the linear-no-threshold (LNT) model of carcinogenesis and remains a matter of debate in the scientific community (Hendee and O’Connor 2012). Indeed, the LNT model of carcinogenesis can be opposed to a hormetic model in which low exposures could indeed bring a protection against cancer (Cohen 2002; Tubiana et al. 2009).