Objective To investigate the value of single photon emission computed tomography/computed tomography(SPECT/CT)fusion imaging for post-implantation dose verification of 125I particles in patients with bone metastases.Methods Forty patients with metastatic bone tumors treated with 125I particles implantation were selected.Within 24 h after 125I particles implantation,patients underwent SPECT/CT fusion imaging and the radioactivity per unit(RPU)was calculated.The treatment planning system(TPS)was then used to obtain the isodose profiles of SPECT/CT fusion imaging results and to calculate the tumor target coverage.The patient's preoperative and postoperative 1 month clinical outcomes,including local tumour remission,pain assessment,quality of life and serum alkaline phosphatase(ALP)levels were compared,and a receiver operating characteristic(ROC)curve was applied to evaluate the predictive value of tumor target coverage on postoperative outcomes.Results The mean number of particles implanted in the target area was 32.52±12.87.Within 24 h of 125I particles implantation,SPECT/CT fusion imaging analysis confirmed a strong positive correlation between the RPU of the radioactive concentration area and the mean dose received by the patient(r=0.786,P<0.05).The predicted area under the curve(AUC)for local tumor remission,pain relief,quality of life improvement and change in ALP levels was 0.789,0.757,0.804 and 0.833,respectively.Conclusion SPECT/CT fusion imaging can be used for postoperative dose verification of 125I particles for metastatic bone tumors and has some predictive value for clinical outcomes.