Variation of 4 MV X-ray dose rate in fractionated irradiation strongly impacts biological endothelial cell response in vitro
Résumé
Comparisons of X-ray beam dose rates are scarce although these beams are widely used in medical diagnosis or radiotherapy. We have recently demonstrated in vitro and in vivo, that for a single dose of irradiation, the relative biological effectiveness (RBE) deviates from 1 when changing the dose rate of high energy X-ray beams. To further investigate the impact of the dose rate on RBE, in this study we performed in vitro fractionated irradiations by using the same two dose rates (0.63 and 2.5 Gy.min-1) of high-energy X-rays (both at 4 MV) on normal endothelial cells (HUVECs). We studied the viability/mortality, measured cellular senescence by flow cytometry and performed gene analysis on custom arrays. Taken together, these experiments show that the RBE of photons deviates from 1 when varying the dose rate of high-energy X-rays in fractionated irradiations. These results strengthen the interest of multiparametric analysis approaches in providing an accurate evaluation of the outcomes of irradiated cells in support of clonogenic assays, especially when such assays are not feasible.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)
