<prompt> Not a radiosensitizing drug -5-FuBUDRCyclophosphamideHydroxyrea  <response>: Ans. is c i.e., Cyclophosphamide RadiosensitizersA Hypoxic cell radiosensitizers1 Nitroimidazoles:- Metronidazole, Misonidazole, Etanidazole, Nimorazole, Pimonidazole2 Anticancers:- Actinomycin D Dactinomycin, Bleomycin, Cisplatin, Doxorubicin, 5-FU, Fludarabine, Gemcitabine, Hydroxyurea, Paclitaxel, Mitomycin - C, Topotecan, Vinorelbine.3 Hyperbaric oxygen most potentB Non hypoxic cell radiosensitizers1 Haloginatedpyrimidines:- BUdR, IUdR.Cisplatin and 5-FU are two of the most commonly used radiosensitizing agents. 