The dose fractionation effect is a recurrent question of radiation biology research that remains unsolved since no model predicts the clinical effect only with the cumulated dose and the radiobiology of irradiated tissues. Such an important question is differentially answered in radioprotection, radiotherapy, radiology or epidemiology. A better understanding of the molecular response to radiation makes possible today a novel approach to identify the parameters that condition the fractionation effect. Particularly, the time between doses appears to be a key factor since it will permit, or not, the repair of certain radiation-induced DNA damages whose repair rates are of the order of seconds, minutes or hours: the fractionation effect will therefore vary according to the functionality of the different repair pathways, whatever for tumor or normal tissues.
Keywords: Cassures double-brin; DNA double-strand breaks; DNA repair; Fractionation; Fractionnement; Radiosensibilité; Radiosensitivity; Repeated doses; Réparation de l’ADN; Répétition de doses.
Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.