Narrow Band Imaging for Nasopharyngeal Carcinoma Detection

Abstract

Objective To determine if Narrow Band Imaging (NBI) improves sensitivity for detection of nasopharyngeal carcinoma (NPC) compared to conventional nasoendoscopy. Methods Consecutive patients suspected of having NPC were recruited prospectively from the otolaryngology clinic, Singapore General Hospital, over 6 months (8/2007 to 2/2008). All these patients had no prior history of having NPC. Examination of the nasopharynx was performed concurrently with both conventional and NBI nasoendoscopy. Photo documentation was carried out in all cases. Lesions identified as abnormal on NBI and/or conventional endoscopy were biopsied for histological confirmation. Concordance with histology was the outcome measure. Results A total of 59 patients were presented for screening of NPC. 7 were positive with NPC on histology and 52 were normal/negative cases. For each patient, both conventional and NBI endoscopy were used for examination of the nasopharynx. The accuracy rate of detection was improved from 98% to 100% by using NBI compared with conventional technique. All 7 positive samples (sensitivity of 100%) were found to be positive by using NBI. With conventional light nasoendoscopy, only 6 positive samples were detected (sensitivity of 86%), and 1 positive sample with focal tumor was falsely detected to be negative. For the 52 normal cases, the diagnostic accuracy was the same for both techniques with the rate of 100% (specificity of 100%). Conclusions NBI endoscopic examination of the nasopharynx for nasopharyngeal carcinoma is found to be more sensitive compared to conventional light endoscopy. NBI nasoendoscopy would be a better screening tool for early NPC as compared to conventional light nasoendoscopy.