Rationale for hypofractionation.

Fractionation was established more than fifty years ago as the best way to obtain a differential effect between tumors and normal tissues. However, new technologies allowed today to spare critical organs from the radiation fields. And so protracted courses of irradiation are no longer required. Hypofractionation have clear practical advantages over classical fractionation: it saves the patient time; it saves money for public health system; it reduces pressure on radiotherapy units. In several localization, it has proved to be as efficient as classical fractionation without increasing late effects. In prostate cancer, some radiobiological considerations argue in favor of a better efficiency, but clinical trials did not demonstrated differences in biological control. In conclusion, for all diseases where hypofractionation was demonstrated efficient, it must be fully implemented. Invoice procedures must be adapted to maintain a sufficient level of reimbursement of radiotherapy centers.