Sir, the recent report on mage-enhanced endoscopy for diagnosis and treatment of gastrointestinal tumor is very interesting.1 Kim and Ku1 noted that the usefulness of these image enhanced endoscopy has not been proven yet, although there are several studies reporting diagnostic superiority of these new imaging methods over white light endoscopy. In fact, the new image-enhanced endoscopy has several advantages. The better visualization can help physician better manipulate the gastrointestinal tumor.2 However, there are some points to be considered. First, there is no systematic evaluation on the cost effectiveness of this new technique comparing to the classical technique. Nishida et al.3 noted and called for the evaluation of the safety and cost effectiveness of this new technique.

We thank Wiwanitkit for the comment.1 As Professor Wiwanitkit said, there are several studies reporting diagnostic superiority of these new imaging methods over white light endoscopy.2-4 However, most of these studies were not based on objective assessments and there was a lack of objective evidence. Although some experts suggest several diagnostic criteria for Barrett's esophagus, precancerous and cancerous lesions with new imaging techniques,5-8 these diagnostic criteria are not standardized and not verified by studies of interobserver reliability. There is no consensus on these diagnostic criteria. Probably these new imaging methods are expected to improve the quality of endoscopic diagnosis; however, there are some drawbacks to be overcome. In order for the new imaging modalities to be helpful in the diagnosis, as we mentioned in the conclusion, there needs to be a standardized diagnostic criteria established through a consensus meeting with interobserver reliability studies. The issue of cost-effectiveness comes later.