Narrow band imaging for risk stratification of glottic cancer within leukoplakia.

BACKGROUND: This study investigates relevance of narrow band imaging (NBI) in stratifying risk of malignant transformation within leukoplakia.

METHODS: We conducted a prospective analysis that included 62 patients with 91 changes of leukoplakia on vocal folds. The NBI was obtained before microsurgery. Categorization of the lesion as benign was made when vessels of surrounding epithelium were classified as type I, II, or IV according to Ni classification. If there were visualized intraepithelial papillary capillary loops of type V, the lesion was classified as malignant. Results were compared to the histopathological diagnosis.

RESULTS: The NBI assessment classified 75 lesions (82.4%) as benign and 16 (17.6%) as malignant. Histopathological results revealed the diagnosis of no dysplastic changes or low grade dysplasia in 77 cases (84.6%). Another 14 cases (15.4%) occurred with high-grade dysplasia, carcinoma in situ, and invasive cancer. Sensitivity, specificity, and accuracy of NBI in predicting malignancy within leukoplakia were 100%, 97.4%, and 97.8%, respectively. The kappa index was 0.92 (95% confidence interval 81.1%-100%).

CONCLUSION: The noninvasive procedure of an NBI endoscopy may be recommended as an accurate method in predicting the risk of malignant transformation within the vocal fold leukoplakia and, therefore, would be useful in the clinic for planning the patient's therapy.