Protocol for the systematic review on special imaging (narrow band imaging and acetic acid chromoendoscopy) for endoscopic surveillance of Barrett’s oesophagus

This research project is a systematic review designed to evaluate the effectiveness of special imaging modalities—specifically narrow band imaging (NBI) and acetic acid chromoendoscopy (AAC)—when used during endoscopic surveillance of Barrett’s oesophagus (BO). Barrett’s oesophagus is a premalignant condition in which chronic reflux leads to metaplastic transformation of the lower oesophageal mucosa, predisposing a subset of patients to dysplasia and ultimately oesophageal adenocarcinoma (OAC). Although the annual risk of progression is low, OAC carries a high mortality rate, making high‑quality surveillance a critical component of early detection and prevention. Current guidelines recommend the use of enhanced imaging techniques to improve dysplasia detection during surveillance endoscopy. However, the evidence supporting these modalities is heterogeneous, spans several decades, and varies widely in study design, population characteristics, and outcome reporting. This review aims to systematically identify, map, and evaluate interventional and cohort studies that have assessed NBI or AAC in the context of BO surveillance. By synthesising the available evidence, the project seeks to clarify the clinical utility of these imaging techniques, highlight methodological strengths and weaknesses in the existing literature, and identify gaps that require further investigation. The expected outcomes of this review include: A comprehensive catalogue of interventional and cohort studies evaluating NBI and AAC in BO surveillance. A structured appraisal of study quality, risk of bias, and methodological limitations. A detailed synthesis of dysplasia and neoplasia detection outcomes associated with each imaging modality. Identification of research gaps, including areas where evidence is insufficient, inconsistent, or outdated. Practical insights to inform clinicians, guideline developers, and researchers regarding the strengths and limitations of current evidence supporting advanced imaging in BO surveillance. Ultimately, this project aims to provide a clear, evidence‑based overview of how NBI and AAC contribute to surveillance quality, where uncertainties remain, and what future research is needed to optimise early detection strategies for patients with Barrett’s oesophagus.