Application Of Narrow-band Imaging (NBI) In Optical Biopsy Of Vocal Foig Leukoplakia

Objective: To observe whether changes in microvessels around the vocal fold leukoplakia under narrow-band imaging(NBI)endoscopy are sufficient to distinguish between benign and malignant vocal cord leukoplakia.Methods: From December 2015 to June 2017,a total of 276 patients with laryngeal leukoplakia lesions were examinated with white light HD video fiber laryngoscopy and NBI endoscopy,of which 72 eligible patients were enrolled.After NBI was used for endoscopic examination,the patients were divided into two groups,malignant intraepithelial papillary capillary loops(group I;30/72)and benign vascular network white spots(group II;42/72),based on the characteristics of microvascular morphological changes around the mucosal leukoplakia.Results: All 72 patients were evaluated by blinded histological examination and the results were compared with NBI optical biopsy.Group I was diagnosed with 25/30(83.3%)in situ carcinoma or invasive squamous cell carcinoma,group II was diagnosed with normal or atypical hyperplasia 38/42(90.5%),and squamous cell carcinoma(including carcinoma in situ)4/ 42 cases(9.5%).The sensitivity of NBI endoscopic optical biopsy and histopathology was 86.2%(95%CI 69.4-94.5%)for vocal cord leukoplakia lesions and 88.4%(95%CI 77.1-97.1%)specificity.NBI endoscopic examination of vocal fold leukoplakia showed good agreement with histopathological features(kappa index=0.74,p<0.001).Conclusion: Optical biopsy diagnosis based on NBI can be more expediently applied to improve the assessment of vocal cord leukoplakia.The close relationship between NBI features and histological findings indicates that negative NBI endoscopic findings can serve as an indication for long-term endoscopic follow-up without histological evaluation.