Discussion
cancer, ESCC
CANCER
In this study, we evaluated the usefulness of an AI system for real-time diagnosis of ESCC in a clinical setting. However, the non-inferiority of the AI system in comparison with endoscopists in the real-time diagnosis of ESCC was not confirmed.We attribute the failure to demonstrate the non-inferiority of the AI system to the following reasons. First, the images used for validation of the AI system in the pre-clinical studies [Second, the proportion of ESCC in the target lesions differs from that in previous studies. In previous studies [The sensitivity and specificity of the AI system can be altered by adjusting the ESCC threshold, and changing this threshold may improve the overall positive diagnosis rate. However, because sensitivity and specificity have a trade-off relationship, it is not possible to improve both by adjusting this threshold. Because the priority of accuracy, sensitivity, or specificity varies depending on the situation in which an AI system is used in clinical practice, it is necessary to set the optimal threshold based on ROC analysis and the needs of the clinical setting.In this study, a total of 237 target lesions were detected in 380 participants, which was a higher frequency than expected. We attribute this to the fact that the previous study [In the subgroup analysis, the sensitivity of the endoscopists was low, especially in lesions < 10 mm. We consider two factors to be the main causes for the low sensitivity of the endoscopists’ diagnoses in our study. One is the prospective study design, which may have resulted in reduced diagnostic performance compared with a retrospective study design [This study is subject to the following limitations. First, this was a single-center study performed at a high-volume center. Second, when the study was planned, we also intended to evaluate the detection and diagnosis of the cancer invasion depth. However, because of the difference between compressed images and original images, estimation of the invasion depth did not improve the accuracy of the AI system, and this feature was not evaluated, thus preventing a comprehensive evaluation of the diagnosis of ESCC. Third, we did not evaluate interobserver agreement or compare diagnostic performance between the endoscopists because the design of this study was not suitable for such assessments. In addition, we have already evaluated these in previous studies [