Impact of NBI on Patients Undergoing Endoscopic Eradication Therapy

Barrett's esophagus (BE), is a condition whereby normal esophageal squamous epithelium is
replaced by metaplastic columnar epithelium, predisposing patients to esophageal
adenocarcinoma (EAC). It is estimated that about 5.6% of adults in the United States have BE
with risk factors including: long standing gastroesophageal reflux disease, tobacco use, male
gender, central obesity, and age over 50 years. EAC is believed to progress in a step-wise
pattern with the following order of non-dysplastic BE, low-grade dysplasia (LGD), and
high-grade dysplasia (HGD). Each carries a risk of progression to EAC, differing by degree of
dysplasia: 0.2-0.5%, 0.7%, and 7% per year, respectively. Given this association, it is
common practice to perform endoscopic surveillance with biopsies in patients with BE.
Endoscopic surveillance has been shown to detect EAC at earlier stages and improve survival
in asymptomatic presentations. As dysplasia in BE may not always be seen as a distinct
lesion, surveillance programs entail use of the Seattle Protocol, a systematic four-quadrant
biopsy technique obtained at 1 to 2 cm increments. Current guidelines recommend the use of
high-definition white light endoscopy (HD-WLE) as it is superior over standard-definition in
regards to improved targeted detection of dysplasia.

Advanced endoscopic imaging techniques have been proposed to improve dysplasia detection with
preference for electronic chromoendoscopy, specifically narrow band imaging (NBI), as it does
not require dye sprays. NBI has been shown to be more accurate in detecting intestinal
metaplasia and HGD. HGD is more often detected in areas with subtle mucosal and vascular
abnormalities, which may be more difficult to see on HD-WLE alone. However, subtle lesions
may go undetected, as NBI is not routinely used in the community with a recent survey showing
only about a third of practicing gastroenterologists use advanced endoscopic imaging. The
widespread use of NBI has been potentially limited by a perceived complexity of
interpretation and lack of standardization. Recently, Sharma et al introduced the BING
criteria - a standardized classification system to detect dysplasia and EAC with NBI. While a
few studies have demonstrated no significant difference in detection of dysplasia or
neoplasia between HD-WLE and NBI, they have had some limitations. The studies occurred prior
to the BING classification system, and participants were limited to a few expert tertiary
medical centers.

The current standard of care for visible lesions identified by HD-WLE (nodules, ulcers,
erosions, or plaques) is endoscopic mucosal resection (EMR). Endoscopic recognition and
appropriate resection of visible lesions is essential for optimal patient outcomes. Staging
EMR is critical as it allows for histopathological "upgrading" or "downgrading" of dysplasia
and ultimately is the best tool for identifying and treating early EAC. Despite the
importance of EMR for BE-AN, survey data suggests it is underutilized in practice with 39% of
academic endoscopists and 13% of community-based endoscopists performing EMR. While many
endoscopists utilize NBI to assist in identification of visible lesions, the resection of
areas deemed "abnormal" by NBI alone is not widely accepted. Moreover, endoscopists at
community hospitals detect neoplastic lesions at significantly lower rates than at BE expert
centers.

Given these data, routine use of NBI prior to EET could significantly impact treatment
decisions among all endoscopists with highly accurate rates of dysplasia detection. It's been
shown that NBI increases the accuracy and positive predictive value of predicting histology
than if HD-WLE is used alone. This study is limited by the use of still-images, which does
not accurately reproduce live images seen during endoscopy. Nevertheless, the current
standard of using HD-WLE for identification of visible lesions likely underestimates the
presence of dysplastic areas in patients undergoing Endoscopic Eradication Therapy (EET) for
BE-AN. We hypothesize that the routine use of narrow band imaging (NBI) for identification of
visible lesions will improve dysplasia detection and have a significant effect on the choice
of primary treatment modality among endoscopists performing EET. To this end, we propose a
video-based study to evaluate the impact of NBI on choice of treatment modality during EET.

Inclusion Criteria:

- Endoscopists familiar with EET.

Exclusion Criteria:

- Endoscopists not familiar with EET or non-endoscopists.

- Special populations will not be included in this study.