White-Light Imaging and Image-Enhanced Endoscopy With Magnifying Endoscopy for the Optical Diagnosis of Superficial Nonampullary Duodenal Epithelial Tumors: A Systematic Review and Meta-Analysis

Background and Aim: Optical diagnosis of superficial nonampullary duodenal epithelial tumors using white-light imaging (WLI) and/or narrow-band imaging with magnifying endoscopy (NBI-ME) is used to guide the treatment strategy and avoid biopsy-induced fibrosis. However, the effectiveness of this approach has not been elucidated. We conducted a systematic review and meta-analysis aiming to investigate the diagnostic yield between Vienna classification category 3 (VCL C3) and categories 4 or 5 (VCL C4/C5) using biopsy, WLI, NBI-ME, and WLI + NBI-ME. Methods: A literature search identified studies on the diagnosis of superficial nonampullary duodenal epithelial tumors using biopsy, WLI, or NBI-ME. A bivariate random-effects model was utilized to analyze the summary estimates of sensitivity and specificity, as well as the area under the summary receiver operating characteristic curves for diagnosing VCL C4/C5. Results: Ultimately, 13 studies were included in the meta-analysis. For the diagnosis of VCL C4/C5, summary estimates of sensitivity, specificity, and area under the curve were for biopsy 47% (95% confidence interval: 37–58), 86% (79–91), and 0.745; for WLI 80% (65–89), 80% (70–87), and 0.859; for NBI-ME were 72% (61–81), 76% (68–85), and 0.811; and for WLI + NBI-ME 88% (67–96), 87% (51–98), and 0.929, respectively. Conclusions: WLI, NBI-ME, and WLI + NBI-ME showed high values for sensitivity and area under the curve. Biopsies can be replaced by WLI, NBI-ME, and WLI + NBI-ME for the preoperative diagnosis of superficial nonampullary duodenal epithelial tumors. However, further accumulation of research findings is needed.