Abstract: Cancer is one of the diseases that seriously harm human health. The cancer-related incidence and deaths are still increasing worldwide, which has brought heavy burden to the global public health system. During the long anticancer history, a variety of methods to treat tumors have been developed. More than 100 years ago, shortly after the discovery of Roentgen rays, people began to treat tumors with radiation, and thus pioneered radiation oncology. As a brachytherapy method, implantation of radioactive seeds acts well, has received public recognition, and becomes an important member of the oncology therapeutic spectrum. In vivo, some seeds can migrate from initial site of implantation to other locations. Permanent interstitial brachytherapy and the incidence, mechanism, influence and prevention of  ¹²⁵ I seed migration were reviewed here.

Key words: Malignant tumor, Brachytherapy, Radioactive , ¹²⁵ I, Seed migration