Objectives: Narrowband imaging (NBI) is a novel optical technique that enhances the diagnostic capability of endoscopes in characterizing tissues by using narrow-bandwidth filters in a video endoscope system. The purposes of this study were to verify the effectiveness of the NBI system in conducting endoscopic screening at the oropharynx and the hypopharynx.
Methods: This study was conducted between July 2005 and August 2005. During this period, 217 consecutive patients with esophageal cancer underwent endoscopic screening of the oropharynx and the hypopharynx with the NBI system at the Department of Otolaryngology, Keiyukai Sapporo Hospital.
Results: Among 217 patients, 6 superficial lesions, at the oropharynx (n = 1) and at the hypopharynx (n = 5), were discovered with the NBI system. On conventional electroendoscopic view, four of six lesions could be hardly recognized because of its small diameter measuring 5 mm or less. The NBI view was more beneficial in recognizing the superficial lesions than conventional electroendoscopic view. Endoscopic mucosal resection was performed for all six patients under general anesthesia in the operation room. The histologic examination exhibited a histologically proven squamous cell carcinoma (SCC) in situ. In our series, the NBI system might improve the sensitivity by about twofold over the conventional method.
Conclusion: NBI may play an important role in the diagnosis of SCCs of the oropharynx and hypopharynx.