Abstract: 5-¹²⁵I-2-deoxyuridine(¹²⁵I-UdR) is specially incorporated into deoxyribonucleic acid during S-phase, where it releases Auger electrons, causing cell death. ¹²⁵I-UdR has been recognized as an effective carrier. On the basis of many animal experiments and clinical trials, it is proved that prolonged continuous or repeated intermittent drug infusions intratumorally leads to favorable antineoplastic efficacy with no significant systemic toxicity, ¹²⁵I-UdR is administered locoregionally in the prevailing circumstances and investigators have been searching for therapeutic efficacy and safety of ¹²⁵I-UdR when combined with other drugs or improved treatment modality locoregionally.