Evaluation of PET/CT combined with HRCT in differentiating malignant from benign solitary pulmonary nodules

Objective: To investigate the clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT combined with high resolution CT (HRCT) to differentiate solitary pulmonary nodule (SPN). Methods: 25 patients with 27 SPN were examined with 18F-FDG PET/CT and HRCT, all of them were proved pathologically or by follow-up. The differential diagnosis of SPN were made using visual method and semi-quantitative method on PET/CT and morphological characteristics on HRCT. The results of 18F-FDG PET/CT and 18F-FDG PET/CT combined with HRCT were compared with pathological results. Results: 15 were malignant and 12 benign among the 27 SPN. 14 SPN were positive on PET/CT among 15 malignant SPN with only one negative less than 10 mm in size. 3 benign were positive on PET/CT, but 2 of them were correctly diagnosed as benign by PET/CT combined with HRCT. The specificity, negative predictive value and accuracy of 18F-FDG PET/CT combined with HRCT were higher than that of PET/CT (91.7%, 93.3%, 91.7% and 93.7% vs 75.0%, 82.4%, 90.0% and 85.2% ). The sensitivity of PET/CT combined with HRCT and PET/CT alone was same (93.3%). Conclusion: 18 F-FDG PET/CT combined with HRCT is a effective no-invasive method in differentiating malignant SPN from benign. (authors)