ObjectiveTo investigate the value of integrin αvβ3 targeted microPET/CT imaging with 68Ga-NODAGA-RGD2 as radiotracer for the detection of osteosarcoma and theranostics of osteosarcoma lung metastasis.MethodsThe 68Ga-NODAGA-RGD2 and 177Lu-NODAGA-RGD2 were prepared via one-step method and their stability and integrin αvβ3 binding specificity were investigated in vitro. Forty-one nude mice were injected with human MG63 osteosarcoma to established the animal model bearing subcutaneous osteosarcoma (n=21), osteosarcoma in tibia (n=5), and osteosarcoma pulmonary metastatic (n=15). The microPET-CT imaging was carried out in 3 animal models at 1 hour after tail vein injection of 68Ga-NODAGA-RGD2. Biodistribution study of 68Ga-NODAGA-RGD2 was performed in animal model bearing subcutaneous osteosarcoma at 10, 60, and 120 minutes. The animal model bearing pulmonary metastatic osteosarcoma was injected with 177Lu-NODAGA-RGD2 at 7 weeks after model establishment to observe the therapeutic effect of pulmonary metastatic osteosarcoma. Histological and immunohistochemistry examinations were also done to confirm the establishment of animal model and integrin β3 expression in animal models bearing subcutaneous osteosarcoma and bearing pulmonary metastatic osteosarcoma.Results68Ga-NODAGA-RGD2 and 177Lu-NODAGA-RGD2 had good stability in vitro with the 50% inhibitory concentration value of (5.0±1.1) and (6.5±0.8) nmol/L, respectively. The radiochemical purity of 68Ga-NODAGA-RGD2 at 1, 4, and 8 hours was 98.5%±0.3%, 98.3%±0.5%, and 97.9%±0.4%; while the radiochemical purity of 177Lu-NODAGA-RGD2 at 1, 7, and 14 days was 99.3%±0.7%, 98.7%±1.2%, and 96.0%±2.8%. 68Ga-NODAGA-RGD2 microPET-CT showed that the accumulation of 68Ga-NODAGA-RGD2 in animal models bearing subcutaneous osteosarcoma and osteosarcoma in tibia and in lung metastasis as small as 1-2 mm in diameter of animal model bearing pulmonary metastatic osteosarcoma. Biodistribution study of 68Ga-NODAGA-RGD2 in animal model bearing subcutaneous osteosarcoma revealed rapid clearance from blood with tumor peak uptake of (3.85±0.84) %ID/g at 120 minutes. The distribution of 177Lu-NODAGA-RGD2 in lung metastasis was similar with 68Ga-NODAGA-RGD2. The number and size of osteosarcoma metastasis decreased at 2 weeks after 177Lu-NODAGA-RGD2 administration and integrin targeting specificity was confirmed by pathology examination.Conclusion68Ga-NODAGA-RGD2 was potential for positive imaging and early detection of osteosarcoma and metastasis. Targeted radiotherapy with 177Lu-NODAGA-RGD2 was one potential alternative for osteosarcoma lung metastasis.