Background:Prostate carcinoma is a common disease that occurs in men over 50 years old. Many studies have explored the effect of free/total prostate-specific antigen (f/t PSA) ratio in monitoring prostate cancer. We conducted a meta-analysis to identify the accuracy of the f/t PSA ratio in the diagnosis of prostate cancer in patients who have PSA levels of 4 to 10 ng/mL.Methods:Databases searched included PubMed and OVID databases, from inception to March 2017, after a systematical review, sensitivity, specificity, and other measures of accuracy of the f/t PSA ratio in the diagnosis of prostate cancer were pooled. We used summary receiver operating characteristic curves to summarize overall test performance.Results:Fifteen case–control studies from 14 articles were identified. The results indicated that the sensitivity of the f/t PSA ratio in the diagnosis of prostate cancer ranged from 0.5 to 0.94 (pooled sensitivity 0.70, 95% CI: 0.67–0.72), whereas its specificity ranged from 0.31 to 0.93 (pooled specificity 0.55, 95% CI: 0.57–0.60). The positive likelihood ratio was 1.85 (95% CI: 1.56–2.20), negative likelihood ratio was 0.42 (95% CI: 0.34–0.53), and diagnostic odds ratio was 4.81 (9.53% CI: 3.33–6.94).Conclusions:The f/t PSA ratio determination has a low sensitivity and specificity for the diagnosis of prostate cancer; it would not be useful for the diagnosis of prostate cancer by itself. The results of f/t PSA ratio measurements should refer to the clinical manifestations and the results of conventional tests such as biopsies.

Background: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.Methods: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.Results: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).Conclusions: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.