[Radiobiology base change: long term effects of ionizing radiation]

By definition, radiobiology studies energy transferring from ionizing radiations to biological material. For a long time, radiobiologists have mainly focused in physical issues and its impact on biological cells and tissues. Moreover, DNA damage, specifically of single and double strands (correctly or not restored by enzymatic repair processes), was studied through diverse mathematical models but only one experimental method: cell death measurement. Today, radiobiology has become again a strictly biological science, focused on the future of energy deposit. Genomic instability is the first step, as it studies the amplification over time of a gene signal in a clonal population derived from a single surviving cell after radiation exposure, independently of initial radiation doses. Bystander effect demonstrates that damage signals may be transmitted from irradiated to non-irradiated cells in a population with the same long term radio-induced effect. Abscopal effect is a reaction produced following irradiation, but occurring outside the site of radiation absorption (for example, from irradiated right lung to DNA damage of the left lung). Clastogenic factors are chromosome damaging substances which are present in irradiated patients's plasma. These data could change the fundamentals of radioprotection, as declared UNSCEAR during the 54th session of may 2006.