Iodine 125 particle implantation therapy, also a method of treating tumors, involves implanting iodine 125 particles emitting low-energy r-rays directly into tumor tissues under CT and ultrasound guidance to provide continuous and maximally destructive killing of tumor tissues. This technique can achieve or approach the effectiveness of other focal destruction therapies for local treatment of tumors. Iodine 125 particle implantation has significant advantages. Not only can it enhance the antitumor effect in synergy with other treatments, but it can also be used as a primary means of treating tumors. For tumors that are insensitive to chemotherapy, unwilling to undergo radical surgery, or cannot be removed by surgery due to physical condition, tumor location and other factors, iodine 125 particle implantation is a better treatment method, which can directly implant iodine 125 particles to inhibit tumor growth and prolong survival. For patients with metastatic tumors, iodine 125 particle implantation can effectively control the growth of primary or metastatic tumor lesions, maintain organ function, reduce pain and prolong life. What is 125 iodine particle implantation therapy? 125 iodine particle implantation is an effective technique for the comprehensive treatment of malignant tumors, which is a kind of brachy-therapy. It is a minimally invasive (percutaneous puncture) or surgical implantation of radioactive 125 iodine particles into tumors or tissues that may be invaded by tumors, as well as into lymphatic channels or lymph nodes where tumors have metastasized. 125 iodine particles emit low doses of r-rays during decay and irradiate tumor tissues continuously without interruption, which can kill tumor cells that have fissioned at different times and oxygen-depleted cells around tumors. Therefore, it can effectively treat tumors and prevent tumor recurrence and metastasis. 125 iodine particle implantation has the following features: 1. 125 iodine particle radiation diameter is only 1.7cm, most of the energy is absorbed by tissues, no special shielding protection is needed; 2. 125 iodine particle implantation irradiates tumor tissues directly, the local irradiation dose is much higher than that of normal tissues; it can kill tumor cells to the maximum extent, with little damage to normal tissues and sensitive tissues; 3. Continuous, low dose 4. The radioactive source is always stored in a special container, and the staff does not touch the particles directly during the operation, which makes the operation safe and easy to protect; 5. 125 iodine particles are radiopharmaceuticals, which need to be ordered by the nuclear medicine department and stored in a special place; 125 iodine particle implantation also needs the cooperation of radiology, B-ultrasound and general surgery. 6. There are certain complications after 125 iodine particle implantation depending on the implantation site. Indications for 125 iodine particle implantation: 1. Untreated primary tumor. 2. 2. Tumors that require preservation of important functional tissues or surgery that will accumulate important organs, such as deep brain tumors 3. Cases in which the patient refuses to undergo radical surgery 4. Prophylactic implantation to prevent local regional spread of tumors and enhance the radical effect 5. Metastatic tumor lesions or postoperative isolated tumor metastases, such as multiple metastases in the lung 6. Inoperable primary cases, such as giant liver cancer 7. 8.Insufficient dose of external irradiation treatment as a supplement of local dose