Narrow band imaging versus lugol chromoendoscopy to diagnose squamous cell carcinoma of the esophagus: a systematic review and meta-analysis

Abstract

BackgroundIn the early stage esophageal cancer, changes in the mucosa are subtle and pass unnoticed in endoscopic examinations using white light. To increase sensitivity, chromoscopy with Lugol’s solution has been used. Technological advancements have led to the emergence of virtual methods of endoscopic chromoscopy, including narrow band imaging (NBI). NBI enhances the relief of the mucosa and the underlying vascular pattern, providing greater convenience without the risks inherent to the use of vital dye. The purpose of this systematic review and meta-analysis was to evaluate the ability of NBI to diagnose squamous cell carcinoma of the esophagus and to compare it to chromoscopy with Lugol’s solution.MethodsThis systematic review included all studies comparing the diagnostic accuracy of NBI and Lugol chromoendoscopy performed to identify high-grade dysplasia and/or squamous cell carcinoma in the esophagus. In the meta-analysis, we calculated and demonstrated sensitivity, specificity, and positive and negative likelihood values in forest plots. We also determined summary receiver operating characteristic (sROC) curves and estimates of the areas under the curves for both per-patient and per-lesion analysis.ResultsThe initial search identified 7079 articles. Of these, 18 studies were included in the systematic review and 12 were used in the meta-analysis, for a total of 1911 patients. In per-patient and per-lesion analysis, the sensitivity, specificity, and positive and negative likelihood values for Lugol chromoendoscopy were 92% and 98, 82 and 37%, 5.42 and 1.4, and 0.13 and 0.39, respectively, and for NBI were 88 and 94%, 88 and 65%, 8.32 and 2.62, and 0.16 and 0.12, respectively. There was a statistically significant difference in only specificity values, in which case NBI was superior to Lugol chromoendoscopy in both analyses. In the per-patient analysis, the area under the sROC curve for Lugol chromoendoscopy was 0.9559. In the case of NBI, this value was 0.9611; in the per-lesion analysis, this number was 0.9685 and 0.9587, respectively.ConclusionsNBI was adequate in evaluating the esophagus in order to diagnose high-grade dysplasia and squamous cell carcinoma. In the differentiation of those disorders from other esophageal mucosa alterations, the NBI was shown to be superior than Lugol.

Narrow-Band Imaging: Clinical Application in Gastrointestinal Endoscopy

“…Regarding the comparison between NBI and Lugol chromoendoscopy, three studies found that NBI and ME-NBI have an increased accuracy and specificity when compared with Lugol, although the sensitivity is similar between the two techniques [15-17]. These findings were also confirmed in two recent meta-analyses [18]. …”

Endoscopic diagnosis and management of early squamous cell carcinoma of esophagus

“…Multiple prospective studies have shown that nonmagnified NBI examination is superior to WLI in detection of early esophageal lesions for screening of high-risk patients (10)(11)(12)(13) (15). In addition, NBI endoscopy also had a higher specificity comparing to Lugol chromoendoscopy (per lesion analysis 82% vs. 37%).…”

Lugol Iodine Staining Test in Early Detection of Head and Neck Cancer

“…There are studies showing that associating lugol iodine test with other optical enhancement examination methods like NBI, SPIES, methylene blue or toluidine blue staining test provide better results concerning macroscopic examination of the head and neck tumor [20,21].…”