Objective To study the cytotoxicity of FUDR on nasopharyngeal carcinoma cell line CNE-1 and evaluate the radiosensitivity of noncytotoxic FUDR,and compare the efficacy with 5-fluorouracil(5-Fu).Methods The concentration suppression rate curve was established by using cell counting kit 8,and ID50 of FUDR and 5-Fu was calculated;then the radiosensitization of low concentration of FUDR and 5-Fu(<1/5 ID50) on nasopharyngeal carcinoma line CNE-1 associated with radiotherapy was determined by clonogenic assay.Cel...