Early and Late Effects of Difluorodeoxycytidine on Murine Cell Radiosensitivity <i>In Vivo</i>

dFdC enhances early radiosensitivity in bone marrow cells, likely by inhibiting DNA synthesis and generating reactive oxygen species (ROS)-induced DNA breaks. Late genotoxic effects were additive and kinetically linked to dFdC incorporation. Both dFdC alone and in combination with radiation exerted prolonged cytotoxic effects on normoblast precursors, with slightly greater toxicity observed in the combination group.