Third‐Generation Narrow‐Band Imaging Versus White‐Light Imaging for the Detection of Early Gastric Cancer: A Randomized Controlled Study

ABSTRACT Objectives The endoscopic system EVIS X1 with improved image quality has been introduced into clinical practice. We examined whether third‐generation narrow‐band imaging (3G‐NBI) is more effective than white‐light imaging (WLI) for detecting early gastric cancer (EGC). Methods Our study, performed at a single center, had a parallel‐group, open‐label, two‐arm, randomized, controlled design. Patients who had undergone endoscopic submucosal dissection for EGC were randomly assigned to a group undergoing 3G‐NBI after initial WLI (initial WLI group) or a group undergoing WLI after initial 3G‐NBI (initial 3G‐NBI group). The primary endpoint was the EGC detection rate of the two methods. The secondary endpoints were as follows: proportions of EGC detected and missed lesions, positive predictive value (PPV) for EGC diagnosis, and observation time for WLI and 3G‐NBI. Results The EGC detection rate was 9.0% (17/188) in the initial WLI group and 8.5% (16/188) in the initial 3G‐NBI group. The missed lesion rate was 5.6% (1/18) in the initial WLI group and 0% (0/18) in the initial 3G‐NBI group. The PPV of the initial WLI group was 42.5% (17/40), whereas that of the secondary 3G‐NBI was 25% (1/4). The PPV of the initial 3G‐NBI group was 30.2% (16/53). No biopsies were performed during secondary WLI. The examination times were 274 ± 78.2 and 280 ± 82.9 s for WLI and 3G‐NBI, respectively. Conclusions 3G‐NBI was not superior to WLI in detecting EGC. This finding is likely due to improved WLI image quality.