Abstract: Objective: To investigate the differential diagnostic value of integrated 99Tcm-MIBI-SPECT/CT after oxygen inhalation for lung masses. Methods: From December 2008 to September 2011, we had prospectively studied 34 consecutive patients with lung masses. All patients breathed oxygen via nasal catheter before 99Tcm-MIBI injection. Ten minutes and 2 hours after 99Tcm-MIBI injection, early and delayed SPECT/CT fusion imaging of the chest was performed, respectively. The uptake ratios of malignant and benign lung masses were compared by independent-samples T test. In addition, the diagnostic efficiency of uptake ratios of lung masses was analyzed with receiver operating characteristic (ROC) curve. Results: There were 27 patients with malignant lung lesions and 7 patients with benign lung lesions. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of qualitative analysis were 100%, 71.43%、94.12%, 93.10% and 100%, respectively. In patients with malignant lung lesions, the early mean T/N ratio value ± standard deviation was 3.29±2.10. Whereas in patients with benign lung lesions, that was 1.55±0.66. In patients with malignant lung lesions, the delayed mean T/N ratio value ± standard deviation was 3.40±2.05. Whereas in patients with benign lung lesions, that was 1.59±0.61. The early and delayed T/N ratio were significantly different between malignant lung lesions and benign lung lesions (t=2.14, t=2.28, respectively. P＜0.05). Semiquantitative analysis showed that for a early T/N value ≥1.87, the value of sensitivity and specificity was 92.60% and 71.40%, respectively (ROC curve), for a delayed T/N value ≥1.78, the value of sensitivity and specificity was 100% and 71.40%, respectively (ROC curve). Conclusion: Our study shows that integrated 99Tcm-MIBI-SPECT/CT takes on highly clinical value in differentiating malignant from benign lung masses, and it is a practical method for medium-to-low income patients with lung masses in small and medium-sized cities.

Key words: Technetium Tc 99m Sestamibi, SPECT, X-Ray Computed Tomography, Fusion imaging, Lung lesion, lung cancer