Clinical utility and effectiveness of a training program in the application of a new classification of narrow band imaging for vocal cord leukoplakia: a multicenter study

OBJECTIVE: To analyse the application of a new narrow-band imaging (NBI) classification in the diagnosis of vocal cord leukoplakia by laryngologists with different levels of laryngoscopic experience and to explore the impact of NBI training programmes on laryngologists' identification of benign and malignant leukoplakia. DESIGN: Prospective multicentre study. SETTING: Tertiary hospitals. PARTICIPANTS: Sixteen laryngologists were divided into less-experienced and experienced groups and received NBI training course. Thirty cases of vocal cord leukoplakia were investigated. MAIN OUTCOME MEASURES: Diagnostic accuracy and interobserver agreement under white light imaging (WLI), before and after NBI training, were analysed among doctors with varying levels of experience. RESULTS: The accuracy in the less-experienced group was significantly lower than that of experience group (0.59 vs 0.69) under WLI. There was no significant difference in the diagnostic accuracy between the less-experienced group and the experienced group before NBI training (0.75 vs 0.74) and after NBI training (0.79 vs 0.83). NBI training could improve the interobserver agreement from fair or moderate to good agreement. CONCLUSION: The new NBI diagnostic classification is helpful for identifying benign and malignant vocal cord leukoplakia. In addition, the NBI training programme can improve the diagnostic accuracy and interobserver agreement of less-experienced doctors to the level of experienced laryngologists.