Effectiveness of FDG-PET Scans in the Evaluation of Patients with Single Pulmonary Nodules in Taiwan

Received 1/29/2004; revised 2/11/2004; accepted 2/19/2004. For correspondence and reprints contact: Wan-Yu Lin, M.D., Department of Nuclear Medicine, Taichung Veterans General Hospital, 160 Section 3, Taichung Harbor Road, Taichung 407, Taiwan. Tel: (886)4-23741349, Fax: (886)423741348, E-mail: [email protected] Background: Lung cancer is one of the most frequent malignancies and a major cause of mortality. FDG-PET scan has been proven to be very useful in the evaluation of single pulmonary nodules in western countries. However, its clinical value for Taiwanese who have a high incidence of infectious disease such as tuberculosis is still not clear. In this study, 15 Taiwanese patients were diagnosed with single pulmonary nodule by CT scans. All these patients were further evaluated with FDG-PET scans for differentiating benign lesion from malignancy. Methods: Fifteen patients with suspected primary pulmonary neoplasm were enrolled in this study. All patients received a thoracic CT scan and a whole body FDG-PET scan before surgery or biopsy. All patients were given a final diagnosis in a histopathologic report from thoracic surgery, CT-guide biopsy or bronchoalveolar brushing. Results: There were 11 lung cancers and four benign lesions in our study. The sensitivity, specificity and accuracy for FDG-PET were 81.8%, 25% and 66.7%, respectively, using a SUV of 2.5 as a cut-off value. Using a SUV of 3 as a cut-off value, the sensitivity, specificity and accuracy were 81.8%, 50% and 73.3%, respectively. Conclusion: Our preliminary study showed that the sensitivity of FDG-PET in the detection of lung malignancy is high, but the specificity is suboptimal when compared to the results in the literature. High incidence of pulmonary infection rate may play a role in low specificity. Based on our preliminary study, a higher SUV as a cut-off value may be useful in improving the specificity in Taiwan.