The Comparison Of Diagnostic Value Of Optical Enhanced Endoscopy(OE) With Conventional White Light Imaging In The Nasopharyngeal Tumor

Background:Nasopharyngeal carcinoma(NPC)is a common head and neck cancer in south east Asia and the current standard technique for NPC diagnosis is histological analysis from a white light endoscopy directed biopsy.Recently,two endoscopic optical enhanced modes were developed for the analysis of NPC.Aim of this study is to investigate the value of optical enhanced endoscopy OE mode 1(narrow band imaging)and OE mode 2(bright light imaging)to compare the diagnosis of nasopharyngeal carcinoma and nasopharyngeal lymphadenosis.Methods:Between March 2019 to December 2019,a total of 27 patients with suspected nasopharyngeal tumour which was found by conventional white light endoscopy in Zhongda hospital were enrolled in this study.All nasopharyngeal masses were divided into nasopharyngeal lymphadenosis and nasopharyngeal carcinoma group.Then,according to the OE1 and OE2 the lymphadenosis and NPC were diagnosed again with the help of EPK-i7000(A)image processing endoscopy system produced by Pentax Corporation of Japan and the endoscopic pictures of the nasopharynx were collected.The biopsy samples were pathologically examined and the diagnosis was considered as the gold standard.Finally,endoscopic images of three modes was compared with histopathological report and the diagnostic value obtained among three different image modes were compared using graph pad prism software.Results:A total of 27 lesions were detected,among which 19 nasopharyngeal carcinomas were pathologically diagnosed as NPC and 8 were pathologically diagnosed as nasopharyngeal lymphadenosis.On the comparison of diagnostic values(sensitivity,specificity,positive predictive value and negative predictive value)between 3 modes of endoscopy for the diagnosis of nasopharyngeal carcinoma and lymphadenosis,the sensitivity,specificity,positive predictive value and negative predictive value for detecting NPC were 73.68,87.50,93.33 and 58.33%respectively with WLE which increased significantly up to 94.74,87.50,94.74 and 87.50%with OE1 and up to 89.47,87.50,94.44 and 77.78%with OE2 respectively and diagnostic values(sensitivity,specificity,PPV and NPV)were 87.50,73.68,58.33 and 93.33%respectively with WLE which increased significantly up to 87.50,94.74,87.50 and 94.74%with OE1 and 87.50,89.47,77.78 and 94.44%respectively with OE2 for lymphadenosis.Although,significant values of all the 3 modes of endoscopy were found to be significant(P<0.05)for the diagnosis of nasopharyngeal carcinoma and lymphadenosis,however,OE modes(OE1 and OE2)had higher significant value than WLE(P<0.0001 and P=0.0003,respectively).Conclusion:Optically enhanced endoscopy,OE mode 1 and OE mode 2 have higher diagnostic values(sensitivity,PPV and NPV)in the diagnosis of nasopharyngeal carcinoma and have higher diagnostic values(specificity,PPV and NPV)in the diagnosis nasopharyngeal lymphadenosis than white light imaging mode.Under OE mode 2,nasopharyngeal carcinoma was also observed as a sinusoidal,serpentine,and scorpion-like microvascular morphology with bright image colour.So,OE mode 2 is a new type of optical imaging technique which can be considered as a worthy diagnostic tool in the diagnosis of nasopharyngeal carcinoma and lymphadenosis.