Confocal endomicroscopy and optical coherence tomography for differentiation between low-grade and high-grade lesions of the larynx

So far, there are no data available from clinical studies that demonstrate in vivo a reliable differentiation between low-grade and high-grade lesions of the larynx. The aim of this clinicopathological study was to compare the OCT and CEM-based targeted biopsies with histopathology. In this prospective study, 67 patients with primary lesions of the true vocal cord suspicious for low-grade or high-grade lesions were included. OCT and CEM were applied during microlaryngoscopy under general anesthesia. Spectral domain OCT was used via a surgical microscope in non-contact mode. For CEM measurements, a rigid endoscope was used in contact mode. In the OCT and CEM study (47 biopsies of 39 patients), sensitivity, specificity, and positive and negative predictive values for CEM were calculated, and these were found to be 90 % (95 % CI of 68-98 %), 92 % (95 % CI of 73-99 %), 90 % (95 % CI of 68-98 %), and 92 % (95 % CI of 73-99 %). OCT revealed values of sensitivity, specificity, and positive and negative predictive values of 86 % (95 % CI of 63-96 %), 81 % (95 % CI of 60-93 %), 78 % (95 % CI of 56-92 %), 87 % (95 % CI of 66-97 %). Inter-rater variability of CEM and OCT images was done with the digitally stored images and resulted in kappa = 0.75 (P < 0.001) for CEM and in kappa = 0.58 (P < 0.001) for OCT. On the basis of a prospective study, OCT and CEM with targeted biopsies show good diagnostic sensitivity and accuracy for detection of high-grade lesions. Further developments, namely, office-based imaging via laryngoscope and further studies, are needed.