Treatment principle: Strontium-89 uses intravenously injected osteophilic radiopharmaceuticals to appear in higher concentrations at the site of bone metastases, and the beta rays emitted by the radionuclide can irradiate the tumor in the body to achieve pain relief and destruction of tumor tissues. Disease characteristics: Patients with tumor bone metastasis are prone to pathological fracture, bone marrow failure, walking difficulties, nerve compression symptoms and hypercalcemia, especially often accompanied by intractable pain. Therapeutic features: 1. Good efficacy: The beta rays released by strontium-89 can focus on the primary bone tumor and metastases, targeting and inhibiting tumor cells. 2.Safety: Strontium-89 has little side effects and has no significant impact on the bone marrow hematopoietic function of patients. 3.Economy: Strontium-89 has long efficacy time, one injection, half year effective, reducing the comprehensive treatment cost of patients. 4.Convenient: outpatient injection in nuclear medicine department, no hospitalization.