A male, 75 years old, had multiple lymph node metastases after thyroid follicular carcinoma surgery. It was thought that follicular thyroid cancer was highly differentiated and not prone to metastasis, but multiple lymph node metastases were detected in 2008. Since the metastatic lymph nodes were mainly located in the upper mediastinum and the trachea was invaded, surgery was not possible. When he heard that thyroid follicular carcinoma is highly differentiated, radiotherapy is not sensitive and iodine 131 is a good treatment method, he put his hope on iodine 131 treatment. Yang Hui, Department of Nuclear Medicine, Henan Cancer Hospital Which thought that he fell right into such a small percentage of patients whose metastases do not absorb iodine 131, 15% of the population. Just when the patient was disappointed and ready to give up the treatment, the doctor of nuclear medicine told him about an advanced tumor nuclide internal irradiation treatment technology – iodine 125 particle implantation therapy. With the attitude of giving it a try, he underwent CT-guided iodine 125 particle implantation treatment for only one lymph node in his neck in December 2008, and was convinced by the excellent treatment effect. Subsequently, he further requested other lesions to continue iodine 125 particle implantation treatment. There are many similar cases where iodine 125 particle implantation has allowed patients with advanced cancer who had failed to respond to conventional treatment to receive unexpected therapeutic results and rekindle their hope for life. Why is iodine 125 particle implantation therapy technologically advanced? Solid tumor iodine 125 particle implantation therapy is a kind of nuclear irradiation therapy. Iodine 125 particle implantation therapy inherits the characteristics of nuclear irradiation targeted therapy. This method is minimally invasive and can be used to implant radioactive iodine 125 particles into the tumor by image guided percutaneous puncture, intraoperative or lumpectomy. The iodine 125 particles implanted in the tumor emit uninterrupted radiation to kill tumor cells, thus effectively treating the tumor. For early stage prostate cancer, this method can achieve the effect of surgical treatment with less side effects than surgical treatment. In developed countries, prostate cancer is the number one tumor in men and already 60% of patients prefer this treatment method for treatment. What are the advantages of iodine 125 particle implantation treatment? 1. Iodine 125 particle implantation is an advanced treatment technology with good efficacy and low side effects; 2. 3. Iodine 125 particle implantation by percutaneous puncture guided by CT, MRI or color ultrasound can achieve the effect of incisionless surgery with less trauma and can be discharged 2 days after surgery; 4. Although iodine 125 particles are radioactive, they have a range of 1.7 cm and do not require environmental contamination or protection; 7.