Narrowband imaging with near‐focus magnification for discriminating the gastric tumor margin before endoscopic resection: A prospective randomized multicenter trial

Abstract

Background and Aim This study investigated the usefulness of near‐focus narrowband imaging (NF‐NBI) for determining gastric tumor margins compared with indigo carmine chromoendoscopy (ICC) before endoscopic submucosal dissection (ESD). Methods This prospective randomized controlled trial was conducted at seven teaching hospitals in Korea. Patients with gastric adenoma or differentiated adenocarcinoma undergoing ESD were enrolled and randomly assigned to the NF‐NBI or ICC group. A marking dot was placed on the most proximal margin of the tumor before ESD. The primary endpoint was delineation accuracy, which was defined as presence of marking dots within 1 mm of the tumor margin under microscopic observation. Results A total of 200 patients in the NF‐NBI group and 195 patients in the ICC group were included. The delineation accuracy rate was 84.5% in the NF‐NBI group and 81.0% in the ICC group (P = 0.44). However, the distance from the marking dot to the margin of the tumor was significantly shorter in the NF‐NBI group than in the ICC group (0.8 ± 0.8 vs 1.2 ± 1.3 mm, P < 0.01). Even after adjustment of other clinicopathological factors that are associated with difficulty of tumor delineation, NF‐NBI did not show significant association with accurate delineation (odds ratio of 0.86, P = 0.60). Conclusions This prospective multicenter study showed that NF‐NBI is not superior to ICC in terms of accurately delineating gastric tumors (NCT02661945).

Near-focus magnification and second-generation narrow-band imaging for early gastric cancer in a randomized trial

“…We assume that the shorted time needed to focus on the lesion is a result of the simple procedure of one-step button for NF-NBI. The usefulness of NF-NBI has been reported in the pharynx, esophagus [12,13] and colon [14,15], however there is only one study in the stomach that assessed the delineation accuracy of EGC margin using NF-NBI [16]. There has been no study that prospectively assessed the diagnostic performance of NF-NBI for newly detected lesions during endoscopy.…”

“…In this study, we only evaluated whether the target lesion was cancerous or noncancerous. To evaluate whether NF-NBI is useful for diagnosing the extent of cancerous areas, a recent prospective study reported that the delineation accuracy rate was 84.5% for EGC margin using NF-NBI before endoscopic resection [16]. Thirdly, our study included only high-risk patients of GC with a history or presence of esophageal or gastric cancer.…”

“…The usefulness of NF-NBI has also been reported for colorectal lesions [14,15]. A recent prospective study reported that the delineation accuracy rate was 84.5% for EGC margin using NF-NBI before endoscopic resection [16].…”

Could near focus endoscopy, narrow-band imaging, and acetic acid improve the visualization of microscopic features of stomach mucosa?

“…In the progression of gastric-related diseases, microscopic features of the stomach mucosa such as venules, capillary network, and the shape and size of gastric fossa and recess have been structurally changed. For the first time, two studies used the NF-NBI mode in the stomach for the evaluation of a tumor lesion and its margin[ 16 , 17 ]. The role of the NF-NBI mode has been assessed recently for atrophic gastritis, according to the Kimura-Takemoto classification and intestinal metaplasia (tubular/granular GP pattern of the corpus)[ 18 ].…”

“…Studies have reported that NF-NBI successfully replaced ME-NBI in the detection of pathological lesions in the esophagus and pharynx as well as the identification of celiac disease[ 12 - 15 ]. Recent studies reported the ability of the NF-NBI mode for the detection of early gastric cancer lesions[ 16 , 17 ]. Two recently published studies considered NF endoscopy in the evaluation of gastric atrophy, intestinal metaplasia, and H. pylori infection[ 18 , 19 ].…”