possible mechanisms of interaction between chemotherapeutic agents and radiation that result in an enhanced effect include ( 1 ) changes in the slope of the dose response curve , ( 2 ) decreased accumulation or inhibition of repair of sublethal damage , ( 3 ) decreased recovery from potentially lethal damage , ( 4 ) perturbation in cell kinetics with an increase of proportion of cells in the sensitive cell cycle phase and proliferative state , ( 5 ) decreased tumor bulk and improved blood supply leading to reoxygenation and recruitment and increased radiosensitivity and chemosensitivity , and ( 6 ) increased drug delivery and uptake .
C0007634
cells
C1516337
cell cycle phase