It is well-accepted that IR can induce cancer even at clinically relevant doses and the relationship between radiation and formation of solid tumors is considered to be linear in the dose range of 0.15–1.5 Gy . Epidemiological data from the Life Span Study of the Japanese Atomic Bomb survivor cohort has provided significant evidence on the causal relationship between IR exposure and carcinogenesis . For low doses (<0.1 Gy), there is a heated debate on the actual relationship between dose and cancer incidence. Even recently the validity of the well-known linear no-threshold (LNT) model has been challenged and many questions are still open regarding if the radiosensitivity of a tissue to malignant transformation increases or decreases with dose and if the actual form of the curve, i.e., linear or curvilinear, etc. .