Added Value Of SPECT/CT Fusion Imaging In Diagnosing Bone Metastasis

ObjectiveTo assess the added value of SPECT/CT fusion imaging in diagnosing bone metastasis and explore the clinical indications of bone SPECT/CT examination,so as to provide guidance on early diagnosis and differential diagnosis of bone metastatic disease.Materials and methods269 patients who underwent 99mTc-MDP whole body planar scintigraphy and local SPECT/CT fusion imaging were recruited in the present study.Two experienced nuclear medicine physicians interpreted the planar,SPECT,CT,and SPECT/CT images,and then gave the location and diagnosis for each lesion.The diagnoses were recorded using a five-point scale(1,benign;2,likely benign;3,indeterminate;4,likely bone metastasis;5,bone metastasis).Final diagnoses were derived from histopathology or clinical/imaging follow-up.According to the final diagnoses,we analyzed diagnostic efficacy of the four examinations and investigated the added value of SPECT/CT in diagnosing bone metastasis.All statistical analysis was performed using SPSS 23.0 software and results were considered significant for ap value of less than 0.05.Results269 patients with 525 lesions were examined.Among them,153 lesions were bone metastases and 372 were benign lesions referring to the final diagnostic standard.The sensitivity,specificity,positive predictive value,negative predictive value and diagnostic coincidence rate of SPECT/CT were 98.7%,96.8%,92.6%,99.4%and 96.6%and AUC was 0.987.They were all higher than PBS,SPECT and CT and the added value of SPECT/CT compared with PBS,SPECT and CT were 57.1%,32.0%and 4.2%respectively.Besides,the added value of SPECT/CT was significantly higher for solitary lesions than for multiple lesions(p<0.05),40.6%for osteoblastic lesions,29.6%for osteolytic lesions and more than 50%for lesions in complex skeletal structures such as spine and pelvis.SPECT/CT also had an added value on tumor staging and clinical management of 59.1%malignant tumor patients.ConclusionSPECT/CT fusion imaging has obvious added value in characterizing bone lesions compared with PBS,SPECT and CT.Performing SPECT/CT on the basis of PBS can significantly increase the diagnostic efficacy for bone metastases.SPECT/CT fusion imaging provides higher added value for solitary bone lesion and lesions in complex skeletal structures such as spine and plays a guidance role in tumor staging and management.But it also has some limitations,thus in the process of clinical application we should use it strictly according to the indications in order to maximize its advantages.