The clinical value of SPECT/CT fusion imaging in the diagnosis of bone metastasis of breast cancer

Abstract

Objective To evaluate the clinical value of SPECT/CT fusion imaging in the diagnosis and differential diagnosis the characteristic of the whole body bone scan radioactive hot lesions in patients with breast cancer.Methods The abnormal radioactive hot lesions of whole body bone scan in 25 patients with breast cancer underwent SPECT/CT fusion imaging immediately.Another whole body bone scan and SPECT/CT fusion imaging were carried out 4 to 8 months later in all these patients.The whole body bone scan images,SPECT/CT images and fusion images were analyzed independently by two experienced nuclear medicine physicians and some of the equivocal CT images were analyzed by an experienced radiologist.Results Among all the 37 abnormal radioactive hot bone lesions,29 (29/37,78.38％) lesions were confirmed metastatic lesions,including 2 vertebral lesions classified as benign lesions on the basis of the first examinations data; and 8 lesions were benign,including a rib lesion classified as benign lesion according to the first examinations data.The difference between whole body bone scan and SPECT/CT examination was statistically significant (x2=6.975,P＜0.05).The bone metastases are located mainly in spine and ribs.The sensitivity,specificity,positive and negative predictive values,and accuracy of whole-body bone scan and SPECT/CT fusion imaging were 82.76％,75.00％,92.31％,54.55％,81.08％ and 93.10％,87.50％,96.43％,77.78％,91.89％,respectively.The area under the receiver operating characteristics curve was 0.860±0.056for whole body bone scan and 0.974±0.020 for SPECT/CT.The area under the curve for SPECT/CT was significantly larger compared with the whole body bone scan (x2=9.924,P＜0.001).Conclusions SPECT/CT fusion imaging is better than whole body bone scan alone to characterize the abnormal bone radioactive hot lesions and it can improve the accuracy of diagnosis.The patients should repeat the modality 4 to 8 months later if necessary. Key words: Breast neoplasms; Neoplasms metastasis; Tomography, emission-computed, singlephoton; Tomography, X-ray computed