Optical coherence tomography for the staging of tumor infiltration in superficial esophageal squamous cell carcinoma

Background: Optical coherence tomography (OCT) is a noninvasive technology that can produce high-resolution cross-sectional images in real-time without acoustic coupling, enabling precise assessment of tumor invasion in superficial esophageal squamous cell carcinomas (SESCCs). Objective: To elucidate the usefulness of in vivo OCT for the staging of SESCCs. Design: A single-center, prospective study in 2 phases: phase I to establish the OCT criteria classified into 3 categories (epithelium or lamina propria mucosa [EP/LPM], muscularis mucosa [MM], submucosa [SM]) and phase II to evaluate these criteria. Setting: An academic medical center. Patients: Sixty-two patients with a histological diagnosis of SESCC by routine endoscopy. In the phase I study, 35 images from 16 patients were used. In the phase II study, 109 images from 46 subsequent consecutive patients enrolled from January 2007 to May 2009 were used. Interventions: We performed OCT for preoperative staging followed by endoscopic submucosal dissection or a surgical procedure and compared precisely the visualized OCT sites with the corresponding tissue sections. Main Outcome Measurements: The accuracy of OCT for the staging. Results: The overall accuracy rate was 92.7% (EP/LPM, 94.9%; MM, 85.0%; SM, 90.9%). The OCT signal penetration depth was sufficient to depict the boundary of the deepest region of cancer, the thickness of which was less than 1.5 mm. Limitations: The small number of patients. Conclusions: To our knowledge, this is the first study demonstrating that OCT might be useful for the preoperative staging of SESCCs with a high degree of accuracy.