Objective To evaluate the diagnostic value of SPECT/CT fusion imaging in indeterminate lesions on ⁹⁹Tc^m-MDP whole-body bone scan in patients with breast cancer.

Methods 210 bone lesions of 132 patients with breast cancer, for whom the natures of the lesions were unable to be determined by the 99xTcm-MDP whole-body bone scan, were examined by the SPECT/CT fusion imaging simultaneously. The natures of the lesions were eventually confirmed by pathology and clinical follow-up. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of SPECT/CT fusion imaging for diagnosing bone-metastases were calculated. In addition, the diagnostic accuracy of SPECT/CT fusion imaging for bone lesions in various parts of the body was also analyzed.

Results ① Of 210 bone lesions, 82 of bone metastases and 112 benign bone lesions were correctly diagnosed by SPECT/CT fusion imaging. The diagnostic accuracy, sensitivity, specificity, positive prediction value and negative prediction value was 92.4%(194/210), 94.3%(82/87), 91.1%(112/123), 88.2%(82/93), 95.7%(112/117), respectively. ②The diagnostic accuracy of ⁹⁹Tc^m-MDP SPECT/CT for spinal bone lesions were significantly higher than that for rib lesions(95.9% versus 83.7%, χ²=7.81, P < 0.05).

Conclusions ① 92.4% bone lesions in patients with breast cancer, which can not determined on ⁹⁹Tc^m-MDP whole-body bone scan, can be diagnosed by SPECT/CT fusion imaging accurately. ②Diagnositic compliance rate of SPECT/CT fusion imaging is different in different parts with obscure lesion, which is the highest in the spine, the minimum in ribs.