Standardized Magnifying Endoscopy with Narrow-Band Imaging-Guided Targeted Biopsy Workflow For Upper Gastrointestinal Precancerous Lesions.

Although early detection of upper gastrointestinal precancerous lesions is vital, subtle mucosal variations often limit conventional endoscopic screening. To address this limitation, we present a standardized targeted biopsy protocol using magnifying endoscopy with narrow-band imaging (ME-NBI). This systematic workflow integrates key microstructural and microvascular criteria-specifically demarcation lines, irregular microsurfaces, atypical microvasculature, and marked glandular distortion-to identify high-risk focal areas for mucosal sampling. In a prospective clinical evaluation involving 161 patients, this standardized ME-NBI workflow was compared with a conventional white-light endoscopic assessment. The application of this protocol significantly enhanced the first-pass positive rate, overall biopsy positivity, and the diagnostic yield of high-risk lesions per biopsy sample, while simultaneously reducing the total number of biopsy samples required per patient. Furthermore, the standardized workflow demonstrated high diagnostic performance, achieving an area under the curve (AUC) of 0.928, and yielded strong interobserver agreement. By establishing objective criteria for target selection, this reproducible workflow reduces operator subjectivity, supports early neoplasia detection, and provides a practical framework for clinical implementation.