Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

Abstract

Background & aims: Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

Methods: Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

Results: A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

Conclusions: An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Figure 1

OCT images of SIM with and without IMC/HGD. (A) OCT image of SIM without dysplasia demonstrates glandular architecture with a relatively low reflectivity. (B) Corresponding histology to (A) with inset demonstrates a low nuclear to cytoplasm ratio in the superficial epithelium. (C) OCT image of IMC/HGD enables visualization of large and irregular glands (arrows). (D) Irregular, dilated glands are also seen in the corresponding histology to (C) (arrows). (E) OCT image of IMC/HGD shows a disorganized architecture and increased surface reflectivity (arrows). (F) Corresponding histology for (E) demonstrates abnormal glandular architecture and an increased superficial nuclear to cytoplasm ratio (inset). Histology: hematoxylin-eosin; original magnification, 40 ×. Scale bars, 500 μm.