The value of 18F-FDG-PET/CT in the diagnosis of solitary pulmonary nodules

Abstract
Solitary pulmonary nodules (SPNs) are common imaging findings. Many studies have indicated that 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is an accurate test for distinguishing benign and malignant SPNs. The aim of this study was to investigate the value of 18F-FDG-PET/CT in the diagnosis of malignant SPNs. We systematically searched the PubMed and Embase databases up to March 2017, and published data on sensitivity, specificity, and other measures of diagnostic accuracy of 18F-FDG-PET/CT in the diagnosis of malignant SPNs were meta-analyzed. Statistical analyses were undertaken using Meta-DiSc 1.4 software and Stata version 12.0. The measures of accuracy of 18F-FDG-PET/CT in the diagnosis of malignant SPNs were pooled using random-effects models. A total of 20 publications reporting 21 studies were identified. Pooled results indicated that 18F-FDG-PET/CT showed a diagnostic sensitivity of 0.89 (95% confidence interval [CI], 0.87–0.91) and a specificity of 0.70 (95% CI, 0.66–0.73). The positive likelihood ratio was 3.33 (95% CI, 2.35–4.71) and the negative likelihood ratio was 0.18 (95% CI, 0.13–0.25). The diagnostic odds ratio was 22.43 (95% CI, 12.55–40.07). 18F-FDG-PET/CT showed insufficient sensitivity and specificity for diagnosing malignant SPNs; it cannot replace the “gold standard” pathology by resection or percutaneous biopsy. Larger studies are required for further evaluation.