Preoperative mediastinal and hilar nodal staging with diffusion-weighted magnetic resonance imaging and fluorodeoxyglucose positron emission tomography/computed tomography in patients with non–small-cell lung cancer: Which is better?

BACKGROUND: To compare the diagnostic capability of diffusion-weighted magnetic resonance imaging (DWI) and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the N stage assessment in patients with non-small-cell lung cancer. METHODS: We performed a meta-analysis of all available studies of the diagnostic performance of DWI and (18)F-FDG PET/CT in the N stage assessment of patients with non-small-cell lung cancer. We determined the sensitivity and specificity across studies, calculated the positive and negative likelihood ratios (LR+ and LR-, respectively), and constructed the summary receiver operating characteristic curves using hierarchical regression models. The methodologic quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. RESULTS: A total of 19 studies met the inclusion criteria and included a total of 2845 pathologically confirmed patients. No publication bias was found. The methodologic quality was relatively high. The pooled sensitivity estimate of DWI (0.72, 95% confidence interval [CI] 0.63-0.80) was not significantly difference between PET/CT (0.75, 95% CI 0.68-0.81; P = 0.09). The pooled specificity estimate for DWI (0.95, 95% CI 0.85-0.98) was significantly greater than (18)F-FDG PET/CT (0.89, 95% CI 0.85-0.91; P = 0.02). For DWI, the overall LR+ was 13.80 (95% CI 4.54-41.95) and the LR- was 0.29 (95% CI 0.21-0.40). For (18)F-FDG PET/CT, LR+ was 6.67 (95% CI 5.20-8.56) and LR- was 0.28 (95% CI 0.22-0.37). CONCLUSIONS: Our study has confirmed that DWI has a high specificity for N staging of non-small-cell lung cancer compared with (18)F-FDG PET/CT and has the potential to be a reliable alternative noninvasive imaging method for the preoperative staging of mediastinal and hilar lymph nodes in patients with non-small-cell lung cancer.