“Bone metastasis” is the abbreviation of tumor bone metastasis, which means that tumors from other tissues or organs of the body are transferred to the bones through blood or other means. The severe bone pain caused by bone metastasis is a tricky problem that can seriously affect the patient’s quality of life. Gao Yongju, Department of Nuclear Medicine, Henan Provincial People’s Hospital Bone metastasis diagnosis: ECT bone scan is often used for diagnosis. A harmless radioactive isotope is injected into the blood, this isotope has a high affinity for bone, and its distribution in the bone can accurately respond to the metabolism and blood circulation of the bone, so the bone lesion (bone destruction) at the isotope uptake of the abnormal changes in the image of the lesion is obtained through the ECT imaging, the lesion image information. Treatment for metastatic bone pain: 1. Drug analgesia (World Health Organization three-step drug analgesia); 2. External irradiation radiotherapy; 3. Surgery; 4. Radionuclide therapy (internal radiotherapy). Radionuclide therapy is to inject radionuclides and their compounds into the body and specifically accumulate in the lesion site, the nuclides decay to emit rays, and use the ß-rays emitted by radionuclides to irradiate the tumor internally to achieve the purpose of pain relieving and killing tumor cells. The indications for treatment include: 1. patients with multiple bone metastases throughout the body and bone pain; 2. abnormal concentration of radioactivity in bone metastases on nuclear bone imaging; 3. white blood cells＞3.5×109/L, platelets＞80×109/L. The commonly used radionuclides in clinic are 89SrCl2 and 153Sm-EDTMP. 89SrCl2 has a high affinity for bone (especially metastatic foci), emits pure ß-rays, ß-rays and ß-rays, and has high affinity for bone, It emits pure ß-rays, ß-rays with a maximum energy of 1.46 Mev, short range, no external contamination, and a half-life of 50.6 days. Pain relief usually occurs 2-10 days after administration and can last 3-6 months.153SM-EDTMP: emits both ß-rays and r-rays, ß-rays have a half-life of 46.3 hours, ß-rays have a maximum energy of 810 Kev and r-rays have an energy of 103 Kev. The advantage of this drug is that it can be utilized for ß-rays for treatment and for r-rays for imaging at the same time. 153SM-EDTMP has a short pain maintenance time of about one month.