CHRONOLOGY OF COMBINED CHEMOTHERAPY (5FU) AND RADIOTHERAPY .2. IN-VIVO STUDY

In a previous study, we reported that repeated combined chemotherapy a nd radiotherapy, and a single combined treatment had different consequ ences. In this study the effect of the chronology of the repeated comb ined treatments was tested, i.e. it was determined whether the treatme nt is more efficient when the first treatment is Fluorouracil or irrad iation or when they are given simultaneously. It was first demonstrate d that, under our conditions, neither radiotherapy nor chemotherapy we re chronodependent. The combined treatments were more efficient that t he single treatment although their chronology had no significant conse quences. Nevertheless, the simultaneous treatment appeared slightly be tter than the administration of Fluorouracil 6 h before or 6 h after i rradiation. These results confirm our in vitro experiments.