Narrow band imaging versus lugol chromoendoscopy in screening for esophageal squamous neoplasia: a randomized trial

An optimal method for endoscopic detection of esophageal squamous cell neoplasia in high-risk individuals is not yet established. We aimed to compare the narrow-band imaging (NBI) and Lugol chromoendoscopy in screening for esophageal neoplasia among patients after treatment for head and neck squamous cell cancers (HNSCC). We randomly assigned 300 patients ≥1 year after curative treatment of HNSCC in a 2:1 ratio to NBI or Lugol endoscopy. Following white-light examination of the esophagus, one of the assigned imaging modality was performed and biopsies were taken from any suspicious lesion identified with NBI or Lugol chromoendoscopy. The primary endpoint was positive predictive value (PPV) of biopsied lesion for diagnosis of esophageal neoplasia (high-grade intraephitelial neoplasia (HG-IEN) and invasive squamous cell esophageal carcinoma, ESCC). The secondary endpoints included number of biopsied lesions, time of esophagus examination, and endoscopy tolerance. In 294 patients (204NBI: 90Lugol) 3 ESCC(1.02%) and 2 HG-IEN (0.68%) were diagnosed. The PPV of NBI and Lugol in per-lesion analysis were 7.69% (95% CI, 0.94%-25.1%) and 8.11% (95% CI, 1.70%-21.9%), respectively (P = 1.0). The NBI outperformed Lugol in the rate of patients requiring biopsy (12.75% vs. 41.11%, P = 0.003), esophagus examination time (3.50 min. vs. 5.15 min., P