Objective: To investigate and compare the clinical significance of (18)F-FDG single-photon emission computed tomography and computed tomography (SPECT-CT) in the diagnosis and staging of lung cancer.
Methods: From July 2005 to July 2007, 71 patients with suspected lung cancer received conventional CT and SPECT-CT examination. Fifty-seven of the 71 patients had definite pathological or cytological diagnosis, consisting of 52 malignant lung tumors and 5 benign pulmonary nodules. Forty-three patients underwent surgical resection with different modes. Thirty-seven of the 43 surgically treated patients had available complete data of CT, SPECT-CT and pathological results.
Results: Taking the pathological diagnosis as gold standard, the sensitivity, specificity and accuracy of diagnosing pulmonary lesions suspected as lung cancer were 84.6% (44/52), 80.0% (4/5), 84.2% (48/57) for conventional CT and 92.3% (48/52), 80.0% (4/5), 91.2% (52/57) for SPECT-CT, respectively. If taking the pathological TNM staging results as gold standard, the concordance rates of TNM staging with pathological TNM staging results was 59.5% (22/37) for CT and 67.6% (25/37) for SPECT-CT. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of staging hilar and mediastinal lymph nodes were 76.9%, 79.2%, 78.4%, 66.6%, 86.4% for conventional CT versus 61.5%, 75.0%, 70.3%, 57.1%, 78.3% for SPECT-CT (P > 0.05), respectively. There was no statistically significant difference between conventional CT and SPECT-CT in the accuracy of diagnosing and staging for the suspected pulmonary lesions (P > 0.05).
Conclusion: SPECT-CT is likely superior to conventional CT in the diagnosing and staging for lung cancer. It can be used as a non-invasive supplementary tool for differential diagnosis between malignant and benign pulmonary lesions and in diagnosis of lymph node > 1 cm in diameter.