Good afternoon, It's a great honor for me to talk here with Pentax people. Today, I¡¯d like to talk about two topics. The first topic is endoscopic treatment of gastric cancer Let me start with history of gastric ESD in Korea. This is the first small clinical report on endoscopic treatment of early gastric cancer in Korea in 1996. Professor Á¤Çöä performed all the procedures, and I was the first author of that report. At that time, I was a senior resident at Seoul National University Hospital. This is one of my early experiences of gastric ESDs in 2005. I used paper medical records and polaroid films at that time. This is a national statistics. For about 3 years, 23 thousands ESDs for EGC was done. In the year 2014, it was 7,734. The mean age of patients were 65 years and male was 74%. Mean duration of hospital stay was 5 days. Mean medical cost in 2014 was 1,305 US dollars. Surgery was done in 6.6% within 3 months. This is the volume of surgery and ESD at my institution. More than 35% of gastric cancer patients are initially treated by ESD in the year 2018. Next topic is indications. Before further discussion, I¡¯d like to make the definitions clear. Indications are different from criteria. Indication is something that we consider before the treatment. Criteria is something we consider after the treatment. Decision about additional surgery is made by the criteria. There are two types of indications. Absolute indication means differentiated type mucosal cancer without ulcer and not bigger than 2 cm. Expanded indications include differentiated type EGCs bigger than 2 cm and selected cases of undifferentiated type EGCs. This is a real world statistics. Among 355 early gastric cancers initially treated by ESD, 120 cases, this is 34 percent, belonged to the beyond absolute indication group. Some of them require surgery. Ten percent of patients in the absolute indication group were initially treated by surgery, and you can see the reason in the box at the right hand-side corner. Suspicious lymphadenopathy is the most common reason for surgery. In Korea, ESD candidates are usually selected by the absolute indications. After ESD, expanded criteria is applied to determine whether the resection was curative. There are controversies about the safety of ESD for expanded indication cases. It¡¯s partially because Korean studies consistently showed higher risk of lymph node metastasis in expanded indication cases than Japanese data. Korean practice guideline for gastric cancer was just released. The first statement is about absolute indication. Endoscopic resection is recommended for well or moderately differentiated tubular or papillary early gastric cancers meeting the following endoscopic findings: endoscopically estimated tumor size 2cm or less, endoscopically mucosal cancer, and no ulcer in the tumor. Let¡¯s talk about expanded indications. Do you think total gastrectomy was necessary for a 45 years old lady with 1 cm signet ring cell carcinoma? In my opinion, it was too much. Less invasive options should be considered. What would you recommend for a 40 years old woman with a small flat signet ring cell carcinoma? I performed ESD and the final pathology was SRC, 10 mm, limited in the lamina propria layer, clear resection margins, and no lymphatic invasion. ESD for expanded indication cases can be selectively performed in the individual cases. Flat small signet ring cell carcinomas are frequently treated by ESD in Korea. Statement 2 is about expanded indications. They say ESD could be performed, and the recommendation level was weak for. Next topic is the outcome. Outcome of endoscopic treatment of EGC with differentiated type histology is well established. We have ITT analysis such as comparison with surgery using propensity score matching. We also have PP analysis such as long-term follow-up data after curative resection or non-curative resection. At my institution, we performed a propensity score-matching analysis between the two groups, endoscopic resection or surgery for differentiated type EGCs. The overall survival was almost the same in the two groups. Because of the metachronous recurrences, disease free survival and recurrence free survival is better in the surgery group. However, there was no difference in the disease specific survival. Next evidence is the PP analysis. It¡¯s a single-arm long-term follow-up data for curatively resected differentiated-type EGCs. Excluding metachronous recurrences, we experienced only one case of local recurrence, and 2 cases of extragastric recurrences. This is the overall survival. There was no statistical difference between absolute indication and expanded indication. There are the pictures of the two extragastric recurrences in our series. The top case belonged to the absolute indication group, and the lower case belonged to the expanded indication group. Many centers recently reported long-term outcome after ESD in Korea. The rate of extra-gastric recurrence is usually less than 0.5%. After the publication, we experienced 7 more extragastric recurrences. And these are the picture just before the ESD. What¡¯s your opinion for this case? Lymph node was found in the CT scan. This is the pathology. Lymph node metastasis was confirmed. The treatment conclusion was curative resection. This is another PP analysis for non-curatively resected differentiated type EGCs. In cases with risk of lymph node metastasis, 70% were operated, and 30% were observed without surgery. In the surgery group, 11 have lymph node metastasis, which means 5.7%. In terms of the overall survival, additional surgery was related with better outcome. Survival benefit of additional surgery after non-curative resection was shown in a propensity matched study by doctor Eom at Korea National Cancer Center. As you can see at the right-hand side picture, the overall mortality of observation group was higher than that of the matched initial standard surgery patients. Maybe we are doing too much surgery after ESD. Do you think surgery is necessary for mucosal cancer with lymphovascular invasion? As you can see in the red box, in lymphovascular invasion positive patients within the traditional absolute indication - mucosal cancer, differentiated type, no ulcer, less than 2 cm, there was no lymph node metastasis in surgery. Careful observation without additional surgery can be an option for this group of patients. Finally, I¡¯d like show you a unforgettable case. I performed an ESD procedure in a surgical ICU. The patients was on ECMO due to dilated cardiomyopathy and was waiting for cardiac transplatation. During the pre-cardiac transplatation workup, an early gastric cancer was found. So I performed an ESD at a surgical ICU. The procedure was done as usual, but the problem was delayed bleeding. The patient could not stop warfarin. Anyway after a successful cardiac transplantation, the patient is still doing well. ESD is widely performed for EGCs in the absolute indication in Korea. Annually, it¡¯s more than 7,000 cases. We are still very careful about expanded indication cases. It¡¯s done usually for flat SRCs less than 1 cm. From now on, I¡¯d like to talk about IMAGINA endoscopes. In Korea, medical doctors should serve in the military for three years. I met the Pentax endoscope for the first time during my military service. The patient had situs inversus. Model EG-2901 was the first video endoscope of the Pentax company. In my institution, we use Olympus, Fujifilm, and Pentax endoscopes. Early this year, we got 4 Imagina endoscope systems and 16 gastroscopes and 12 colonoscopes from the Pentax company. Personally, I use the Pentax system in the majority of my endoscopic procedures. Major advantages of Imagina system and i10c scopes are Full HD image quality and i-scan image enhancement function, LED light source at the distal end of the insertion part, i-Pad style touchscreen, and water jet function. Personally, I love the high quality closed up images of the Imagina endoscopes. This is a case with hereditary hemorrhagic telangiectasia, and the images in the upper panel were taken with high magnification zoom endoscopes from Olympus. Lower images were Imagina endoscopy pictures. Fine vascular patterns were clearly seen without zoom function. This is a duodenal ulcer in the active stage. Surface pattern of the edematous margin was clearly observed. This is a gastric submucosal tumor. RAC, regular arrangement of collecting venules, are clearly seen in this beautiful image. This is esophageal glycogen acanthosis and gastric hamartomatous polyposis of a patient with Cowden syndrome. The control part of the Imagina endoscopes was ergonomically designed. Angulation is very good. I regularly organize basic endoscopy training workshops with Pentax Imagina endoscopes In the box simulator training, I emphasize to have a good examination routine. It means good habit and no blind area. Left-hand side is a Koken simulator endoscopy and you can compare with the real patient endoscopy. As you can see, it is quite similar. Beginners can learn a lot of technical tips with gastroscopy simulator training. I also made a VOD manual of gastroscopy hands-on training using IMAGINA i10c scope. In the endoscopic treatment of gastric cancer, determination of the tumor margin is very important. It is much easier with fine closed-up images of Imagina endoscopes. Good angulation is also very helpful. This is a recent ESD procedure using Pentax imagina endoscopes. There were two small cancers in one resected specimen. Pathological conclusion was curative resection. The chance of recurrence will be less than 1 percent. Another case. The conclusion was also excellent. Splash M-knife is a new multi-functional ESD knife from Pentax company. It has a needle-type tip with hooking mechanism. AT the distal end of the knife, there is a metal plate which is useful for bleeding control even in retracted position. The length of the ESD needle is 2mm in extended position and 0.5mm in retracted position. In my recent experience with Splash M-knife, I found three advantages. First the hooking mechanism is very useful for the submucosal dissection step. Second, the metal plate at the distal end of the Splash M-knife provides enough contact area for the bleeding control during the ESD procedure. Finally, the procedure time is much saved due to the water jet function. In a recent study from Japan, ESD using Splash-M knife appeared to reduce the usage of hemostatic forceps during the gastric ESD without increasing the adverse effects. It can reduced the total cost of the treatment. This is my recent case. The procedure was done with Pentax Splash M knife. Minor bleeding was controlled with Splash M knife without speciliazed hemostatic forceps. There are two USB ports for video recording. It is very easy to make a short video clips on USB memory. This is an example how I use the video clips in my presentation. It is quite easy to make with Pentax Imagina endoscopes. From now on, I¡¯d like to talk about ESD training with EndoGEL plate and Imagina system. Stepwise ESD training at my institution starts with basic training with ESD bags and ESD brushes. Next step is EndoGEL ESD, Ex-vivo pig stomach ESD, live pig ESD and finally the real clinical case ESD. Movement of ESD knife is mostly circular and horizontal. For the training of knife control in the circular and horizontal direction, I developed training modules. ESD bags for circular training, and ESD brushes for horizontal training. Horizontal movement training with biopsy forceps can be done on the ESD brush. This is the artificial layer EndoGEL. Artificial mucosa (EndoGEL) is a good alternative of ex-vivo pig stomach. It was originally released in a paper box. But we are using the EndoGEL with Koken gastroscopy simulator and Pentax Imagina endoscopes, because it is more realistic. I recently made a docking station, or a platform for EndoGEL ESD in the Koken simulator. In the endoGEL ESD hands-on, traction method is usually needed due to the mucosa is not real. We are using Pentax Splash-M knife for the EndoGEL ESD hands-on training. Steps of EndoGEL ESD hands-on training We are organizing a lot of EndoGEL ESD hands-on training sessions in various occasions. This is the 3rd therapeutic GI endoscopy and ESD training in Daegu. EndoGEL ESD training can be done at any place even at a conference booth. It was a live demonstration and hands-on training at KDDW - Korean DDW 2019. This is my recent EngoGEL ESD training unit with Pentax Imagina system and its training manual. Tele-mentoring using iPhone Facetime app is a very useful tool for ESD beginners. International mentoring is also possible. If you want some real-time comments from me, send me an e-mail (stomachlee@gmail.com). For the foreign doctors, one-week ESD training course is also available at Samsung Medical Center. There will be (1) introductory lectures, (2) ESD observation, (3) ESD conference and ESD planning session, (4) Hands-on training using EndoGEL (artificial layer) or live pig. Due to the COVID-19 pandemic, the program is temporarily stopped. I hope I can do it in the near future. This is my last slide. Imagina system and i10c endoscopes are really wonderful instrument for me. Thank you for your attention.