The differentiatial diagnostic value of 99Tcm-MIBI SPECT combined with localizable CT imaging in oxygen intervention for lung lesions

Objective To investigate the differentiatial diagnostic value of 99Tcm-methoxyisobutylisonitrile ( MIBI ) SPECT combined with localizable CT in the evaluation of oxygen intervention for suspicious lung lesions,and to establish a cost-effective imaging modality in the detection of malignant lung lesions.Methods From September 2008 to March 2009,47 consecutive patients with suspicious malignant lung lesions underwent 99Tcm-MIBI SPECT/CT prospectively. Patients with suspicious pneumonia were treated with antibiotics for about 4 d before imaging. All patients were cannulized with a nostril tube for oxygen inhalation before 99Tc-MIBI injection. SPECT combined with localizable CT of the chest was performed at 10 min and 2 h after 99Tcm-MIBI injection. The uptake ratios of lesion to contralateral normal lung parenchyma(early uptake ratio:EUR and delayed uptake ratio:DUR) were compared using independent-samples ttest. In addition,the diagnostic efficiency of uptake ratios of lung lesions was analyzed with receiver operating characteristic (ROC) curve. Results Forty-seven patients ( primary lung cancers:32,metastatic tumors of the lung:4,benign lung diseases:11 ) had 51 lung lesions,including 39 malignant and 12 benign lung lesions. The sensitivity,specificity,accuracy,positive predictive value (PPV),and negative predictive value (NPV) were 94.9% (37/39),83.3% ( 10/12),92.2% (47/51),94.9% (37/39) and 83.3% ( 10/12),respectively. The EUR of malignant lesions was 2.95 ± 1.16,whereas of benign lesions was 1.43 ±0.33. The DUR of the malignant lesions was 3.19 ± 1.74,whereas of benign lesions was 1.60 ±0.32. Both EUR and DUR were significantly different between malignant and benign lung lesions,respectively (t= -4.44,-3.12,respectively,both P＜0.01). The ROC curve showed that EUR value ≥1.625 provided the sensitivity of 97.4% (38/39) and specificity of 83.3% (10/12); DUR value ≥ 1.75provided the sensitivity of 94.9% (37/39) and specificity of 83.3% (10/12). Conclusion 99Tcm-MIBI SPECT combined with localizable CT imaging in oxygen intervention has a potential value in differentiating malignant from benign lung lesions. Key words: Lung neoplasms;  Oxygen;  Tomography,emission-computed,single-photon; Tomography,X-ray computed;  MIBI