Comparison of (18)F-FDG PET/CT and DWI for detection of mediastinal nodal metastasis in non-small cell lung cancer: A meta-analysis

BACKGROUND: Accurate clinical staging of mediastinal lymph nodes of patients with lung cancer is important in determining therapeutic options and prognoses. We aimed to compare the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in detecting mediastinal nodal metastasis of lung cancer. METHODS: Relevant studies were systematically searched in the MEDLINE, EMBASE, PUBMED, and Cochrane Library databases. Based on extracted data, the pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR) with individual 95% confidence intervals were calculated. In addition, the publication bias was assessed by Deek’s funnel plot of the asymmetry test. The potential heterogeneity was explored by threshold effect analysis and subgroup analyses. RESULTS: Forty-three studies were finally included. For PET/CT, the pooled sensitivity and specificity were 0.65 (0.63–0.67) and 0.93 (0.93–0.94), respectively. The corresponding values of DWI were 0.72 (0.68–0.76) and 0.97 (0.96–0.98), respectively. The overall PLR and NLR of DWI were 13.15 (5.98–28.89) and 0.32 (0.27–0.39), respectively. For PET/CT, the corresponding values were 8.46 (6.54–10.96) and 0.38 (0.33–0.45), respectively. The Deek’s test revealed no significant publication bias. Study design and patient enrollment were potential causes for the heterogeneity of DWI studies and the threshold was a potential source for PET/CT studies. CONCLUSION: Both modalities are beneficial in detecting lymph nodes metastases in lung cancer without significant differences between them. DWI might be an alternative modality for evaluating nodal status of NSCLC.