Call for International Fellow Applications

My name is Altin Hysa, and I am a gastroenterologist from Tirana, Albania, with a strong interest in advanced interventional endoscopy, a field that is still developing in my country.
Having the possibility to visit the NTT Medical Center twice, first as a short-term fellow from　January 2024 and then as a long-term fellow from April to October 2025, was one of the important professional steps in my career as an interventional GI endoscopist. The NTT journey started in September 2023 in Strasbourg, France, when in an ESD hands-on training, I had the opportunity to meet Dr Ohata in one of my hands-on ESD courses. I asked him if it might be a possibility to visit the endoscopy department in NTT Medical Center in Tokyo. In the next week I was surprised by receiving an invitation email from his team, asking me about the plan and details of my visiting fellowship.
During my experience at NTT, I had the chance to observe a large number of ESD procedures on a daily basis. The volume of cases and the detailed explanations during each procedure made this experience unique. Learning directly from top world-renowned experts in interventional endoscopy, discussing strategy and technique in detail, management of complications and real-time decision-making was like a live masterclass every single day.
The training was comprehensive and had different parts. Extending knowledge in magnifying endoscopy and advanced diagnostic techniques, practicing on ex vivo models and simulators, participating in daily morning and post-procedure case discussions, increased my knowledge and made me more confident. Most importantly, after obtaining a temporary license by Ministry of Health and Welfare of Japan, I had the chance to perform ESD in real patients under expert supervision, receiving immediate feedback and guidance.
Thanks to this structured and immersive experience, I returned to my home country with the confidence and competence to start performing ESD independently. As one of the first physicians in my country introducing and implementing ESD and other resection techniques in the GI tract, it has been both an honor and a responsibility at the same time, that it would not have been possible without the NTT training.
Meeting and sharing experiences with international co-fellows from different parts of the world, building friendships as well, was another interesting part of this training.
I would like to sincerely thank the entire NTT Endoscopy team for their generosity, patience, and dedication to welcoming and teaching us, especially Dr Ohata and Dr Minato for their mentorship and for creating such an inspiring learning environment.
For me, endoscopy department at NTT is much more than endoscopy center of excellence —it’s a place where fellows from all over the world grow, gain confidence, and feel part of a truly international family.

My name is Dr. Rosula Castillo Sánchez, I am a gastroenterologist from Peru. I had the privilege of joining NTT Medical Center Tokyo as a long-term international trainee from November 2024 to November 2025.
My training at NTT was one of the most formative stages of my development as an endoscopist. I was exposed to a highly structured approach to diagnostic endoscopy, particularly in the detection and characterization of early gastrointestinal neoplasia, as well as advanced therapeutic procedures including complex ESD cases.
During the first months of the program, I participated in hands-on training using experimental models. Later, after receiving clinical authorization in Japan, I had the opportunity to actively participate in advanced endoscopic procedures and to perform selected therapeutic procedures, including ESD and EMR, under expert supervision in clinical cases.
I am especially grateful to Ken Ohata and the entire endoscopy team. Learning from senior physicians, fellows, nurses, and biomedical engineers in such a collaborative environment was truly inspiring.
Since returning to Peru, I have been applying these principles in my daily practice, particularly in the early detection and endoscopic management of premalignant and early malignant lesions. I am sincerely grateful to the entire NTT team for their generosity in teaching and for fostering a strong international academic community. This experience will continue to inspire my professional growth.

My name is Ioannis Marakis, and I am a Gastroenterologist at Metropolitan General hospital in Greece.

I participated in the ESD and Magnifying Endoscopy Training Course at the NTT Medical Center Tokyo, organized by Dr. Ken Ohata and his distinguished team, with the goal of further developing my expertise in advanced diagnostic and therapeutic endoscopy.
From the beginning of the program, the physicians and staff created an exceptionally supportive and well-structured educational environment. Their professionalism, dedication to teaching, and willingness to share knowledge greatly contributed to a highly rewarding training experience.

During the course, I had the opportunity to observe numerous complex endoscopic submucosal dissection (ESD) procedures performed by a highly experienced team. Observing these cases provided valuable insight into advanced techniques, procedural strategies, and clinical decision-making in challenging endoscopic resections.
The program also included regular lectures on important topics in diagnostic and therapeutic endoscopy. These sessions were consistently well organized, academically stimulating, and highly educational.
Hands-on training sessions were held every other week, allowing trainees to practice ESD techniques using simulators such as the G-Master system and porcine models under the supervision of Team Ohata physicians. These sessions were particularly valuable for improving technical skills and gaining confidence in lesion resection strategies.

As a long-term trainee with temporary medical license I was also able to participate more actively in clinical practice. This included performing pre-ESD lesion evaluation using magnifying endoscopy and chromoendoscopy, as well as participating in ESD procedures under expert supervision.
During my stay in Japan, I also attended the Japanese Digestive Disease Week in Kobe, which was an excellent opportunity to broaden my academic perspective and bond even more with the team.

Overall, this program has been one of the most valuable training experiences of my career. I am deeply grateful to Dr. Ohata and the entire team for their dedication to education and for their warm support throughout my training.

The training programs for international fellows are fantastic. Dr. Ohata’s team put much efforts on the courses. Aside from a bunch of colorectal, gastric, esophageal, and duodenal ESD, there are lectures once every week, and hands-on ESD on porcine model. Here I can watch ESD done not only by experts, but also by trainees. As a beginner like me, it’s great to see different levels of skills and the potential problems they will encounter. By seeing how the experts teaching the trainees, sometimes I can learn more than just merely observing the procedure itself. The doctors, technicians, and nurses are kind. When we have questions, they try their best to answer us. When we ask things that are not in the routine training, such as observing ERCP, observing colorectal surgery after conversion from ESD, joining the ward round, having conversation about their training system and workload, and so on, they are usually open minded and willing to satisfy our curiosity. After returning to my place, I’m surprised that there’s even a questionnaire for international fellows to help them improving the program. If someone ask my opinion on which hospital to visit if he or she wants to observe ESD in Japan, I will definitely recommend NTT Medical Center Tokyo.

I am Dr. Rizza J. Umali, a General Internist from the Philippines and aspiring to become a Gastroenterologist and Endoscopist. I applied for the program to gain exposure and knowledge with basic endoscopic techniques as well as diagnostic and therapeutic endoscopy especially ESD in Japan. It was an honor and privilege to observe and train under the supervision of Dr. Ken Ohata and his exceptional team of Gastroenterologist and Endoscopist. I was mentored by Dr. Nao Takeuchi, Dr Rindo Ishii and Dr. Yohei Minato. For the past 3 months of my stay in NTT MCT from August to November 2022, I was exposed to different ESD cases from upper to lower gastrointestinal lesions. The unparalleled level of skill and continuous innovation of their technique has brought me awe and amazement. ESD itself is truly hard but the approach and individualized plan which is very unique in every case is much harder and complex. I am also very impressed with their Screening program, the meticulous and adept screening method that even the smallest lesion that could be missed has paved the way to decrease GI cancer in their country. Furthermore, I have the opportunity to attend lecture series about Esophageal, Pharyngeal and Gastric ESDs, Resection of Colorectal Polyps, Cold Snare Polypectomy, Scoring Method for SNADET, Traction method and most of all which have gained impact is the Scope Manipulation and technique under the supervision of Dr. Ryoju Negishi. Hands-on practical training on porcine models as well as scope insertion in phantom model gave us a surreal experience, simulating it like to a real patient. I was also given the opportunity to attend the annual Japan Digestive Disease Week 2022 in Fukuoka, Japan where I learned different gastrointestinal researches and developments in Japan. Lastly, apart from the training itself, I gained mentors at the same time friends. I was able to appreciate the diverse and rich Japan culture, the food and drinks and lastly how accommodating and kind Japanese people were. Training at NTT Medical Center Tokyo has given me different perspective in life and completely changed me into something better, as a doctor and as a person. I will forever be grateful to everyone, to the whole Gastrointestinal Endoscopy department, Dr. Ken Ohata, all doctors and consultants, endoscopic engineers, nurses and staff for the generous help and support during my stay in the hospital. More power to TEAM OHATA!

The training program at NTT Medical Center under Prof. Ohata is extremely well designed and resourceful.
Their ESD volume is around fifteen cases every week.
The training involves case based discussion about endoscopic diagnosis and various resection/closure strategies of each case.
They have interactive, weekly lectures on practical topics explaining their methodology as well as the latest protocols/guidelines.
They have weekly hands-on training on pig model where adequate time and guidance is given to each candidate.
For long term trainees, after a temporary licence is obtained, they are allotted ESD cases where they are allowed to perform the entire case under expert guidance.
The department is involved in various research protocols and are always open to facilitate and discuss any ideas.
The entire team is very welcoming, friendly, can communicate in English and is extremely dedicated to conducting all aspects of this training program. They also organize social gatherings whenever the time permits
The environment is very relaxed and there is full freedom given to the foreigners in case they want to excuse themself for sometime to explore the country/city.
The training experience at NTT has resulted in fundamentally upgrading my understanding of GI endoscopy and enhanced my skillset. Prof. Ohata has also allowed me to lead various research projects which I could present at conferences all over the world and subsequently publish.
They are very communicative even after the training is over and when you are back home for any practical doubts you may face and to discuss any research ideas you may have.
Personally, I have formed a very close, lifelong friendship with certain members of the team.
I am grateful, honoured, and fortunate to have been trained here.

It was an honour to be allowed the opportunity to observe, learn and participate in the Gastroenterology Program at NTT Hospital in Tokyo, Japan.

I was an Endoscopy Fellow from Auckland, New Zealand, practicing independent endoscopy but very keen to learn advanced diagnostic and therapeutic Endoscopy.

The goals of my 4 months at NTT were to improve my luminal endoscopy, in particular in-vivo endoscopic diagnosis and resection of lesions with ESD. I was fortunate to work under the guidance of Dr. Ken Ohata and his excellent team.

Here I was exposed to many new techniques, ideas and a passion for teaching endoscopy that in my experience is unmatched. They created an incredibly supportive environment, with amazing patience to explain, demonstrate and then supervise me in performing all aspects of endoscopy. There were additional teaching sessions on basic science, endoscope handling and technique, improving aspects of basic endoscopy such as colonoscopy insertion, tips to application of abdominal pressure, use of animal models, and diagnostic pre-ESD examinations using magnification, virtual and dye chromoendoscopy and then mucosal resection, including EMR-L, EMR-C and ESD. There is routine and regular teaching sessions with histology and clinical correlation which further enhances understanding. Since this time, I have returned to New Zealand and have been able to successfully adapt their tricks, tips, ideas, techniques and concepts to improve my practice, including ESD.

In addition, they showed me through their action and observation how to improve as a teacher myself. At their institution, teaching is seen as an expectation and taken very seriously. There was a constant and unwavering pursuit of excellence, and I was inspired by their dedication to this craft, astonishing attention to detail, understanding, knowledge and then finally execution of complex procedures.

I am exceptionally grateful to everyone on the team, including my supervisors, Dr. Ohata and Dr. Muramoto and my mentors, Dr. Minato and Dr. Konishi who were always friendly and supportive. I thoroughly enjoyed my time there, and got to know all of the team and other trainees, with Japanese hospitality and teachings of culture and of course delicious Japanese food. Furthermore, we all managed to improve our English and Japanese and intend to keep in touch, with collaborations to come in the future.

It is without hesitation that I say my time in this Endoscopy Unit with Dr. Ohata and his team was the greatest learning experience of my career so far, and I would highly recommend it to anyone interested in learning more about Endoscopy.

Introduction of myself
I work as an associate consultant surgeon, specializing in colorectal surgery, in Princess Margaret Hospital in Hong Kong. Apart from surgeries, I also have special interest in therapeutic endoscopy, as I believe that early diagnosis and treatment of mucosal lesions is also an important part in the management of colorectal malignancy.

Why do I want to learn ESD in NTT?
Since the introduction of colorectal cancer screening program in Hong Kong, many dysplastic and early malignant colonic lesions are now detected by colonoscopy. Treatment of these lesions by endoscopic mucosal resection is suboptimal due to piecemeal resection and positive margins. Endoscopic submucosal dissection (ESD) emerges as an essential yet advanced endoscopic technique for these lesions. Dr. Ken Ohata is a world-renowned expert in ESD. I am deeply inspired by his books including “大圃流” and “The Text ESD” which illustrated step-by-step the strategies of ESD. By grasping these fundamental concepts, ESD appears more “user-friendly”, efficient and precise. In fact, Dr. Ohata and his team had managed the highest number of ESD cases in recent years in Japan.

My experience in NTT
I am very happy to obtain a 4-week clinical observership in NTT Medical Centre Tokyo in July 2019. When I received the reply from Dr. Ohata, it was like a fan’s dream come true! Dr. Ohata demonstrated his techniques to me and other fellows like in a masterclass, which indeed was so mind-blowing and amazing as in a magic show. He was passionate in sharing his principles, skills and experience with us. Like Dr. Ohata, the senior members were all very willing to teach and offer supervision to trainees. They were very helpful and always explained to us about the procedures. I was impressed by their dedication to achieve the best performance outcomes and patients’ satisfaction. Team spirit and working atmosphere was good like in a big family. On one busy day, even though the last procedure finished late, all staff members gathered around and provided peer support until the end of the procedure. ESD cases were very diverse, ranging from upper gastrointestinal tract to lower gastrointestinal tract, extending to other technically demanding areas like in the duodenum and pharynx. I am very grateful that they organized a hands-on training session on porcine model for me. Dr. Minato was my tutor and it was an invaluable opportunity to try on and practice under his guidance. I also felt delighted to have hotpot and Japanese dinner gatherings with their residents where we exchanged not only on the medical knowledge but also our interesting cultural differences. Last but not least, I am truly thankful to Dr. Muramoto for his coordination in my attachment all along.
Having these exposures in NTT Endoscopy Unit, I gained more confidence in establishing the new ESD service in my own center. I have performed 10 cases so far. I am proud to be one of the many international followers of Dr. Ohata. I look forward to visiting again in the future to continue my learning and to meet my friends here in NTT.

Introduction of yourself
My name is Xiquan Ke. I am an attending GI doctor and associate Professor from Anhui Province, China. I went to study in Johns Hopkins University as a joint PhD candidate of gastroenterology in 2014, and got a MD degree in 2016. I am very interested in diagnosis and treatment for early GI cancer.
Motivation for coming to NTT Medical Center Tokyo (NTT MCT)
From international and Chinese conferences of endoscopic performance, I know that Dr. Ohata is a very reputable and charmful endoscopic expert, whose skillful operation of endoscope seems like floating clouds and flowing water and like the endoscope is an integral part of his body, so he has a laudatory title of “God Hand”.
I am one of lots of loyal fans of him in the world, worship him very much. Secondly, his masterpiece of “Operative skill of ESD” is very popular in China, which not only can be used as a standard textbook for beginners, but also can provide reference for experienced ESD doctors. The book is very beneficail to deepen the understanding of ESD, shorten the learning curve and improve medical safety.
At last I find that Dr. Ohata’s team specializes in diagnosis and treatment of early-stage gastrointestinal(GI) cancer, which is very significant for the study of endoscopy and gastrointestinal carcinoma and fits my background very well. I was very interested in his proficient operational skills and advanced conception of digestive endoscope technique, I also hope to improve skills in advanced endoscopy and to learn the early GI knowledge systematically in Japan.
After I had learned that Dr. Ohata and NTT Medical Center Tokyo can provide an opportunity to study ESD for visiting doctor and visiting scholar, so I wrote to the apply the position immediately. Thanks for the help of Dr. Muramoto and Kimoto from Ohata’s team in my visa application and preparation.

Impression of NTT Medical Center Tokyo
There are the cases for ESD treatment of early colon cancer in NTT Medical Center Tokyo which rank Number 1 in Japan and in Asia, the visiting doctors of digestive endoscopy center in NTT Medical Center Tokyo are attracted by the excellent ESD technology of Dr. Ohata, who are from Japan, China, Britain, Hong Kong, Taiwan, Israel, Italy, Switzerland, Vietnam, Malaysia, Russia, New Zealand and other countries all over the world.
Everyone come from all corners of the world to gather together for a common goal to improve the diagnosis and treatment of early GI cancer and ESD operation. Therefore, we can communicate happily, I am able to understand the medical education background and medical development status of early GI cancer in different countries.
There is discussion of difficult cases of early GI cancer on at 6-7AM on very Wednesday morning, the resident doctor reported on diagnosis and treatment for different types of early gastrointestinal cancer, early colon cancer, gastric cancer ,esophageal cancer, etc. There is the latest progress of endoscopy and digestive diseases at 7-8AM.
During the academic report, the report process may be interrupted at any time by senior doctors such as Ohata, the discussion of break the casserole and ask the end is very interesting and meaningful.
Preparations of ESD and other operations for early GI cancer is started At 8:15AM.
There are lectures for GI cancer one time every 1-2weeks and hand-on ESD traning in animal model one time every 3-4weeks for the short-term visiting doctors less than three months, so we can learn the NBI-ME, EUS, FNA, DBE for UGIB, ERCP, EVL and ETI for EGV, ERCP, EPMR, EFR and ESD techniques systematically and comprehensively with the guidance of teachers from Dr. Ohata’s team in the endoscopic center.
There will be an opportunity to do ESD for clinical patients for visiting doctors more than three months if your endoscopic technique has been evaluated and passed by the team, I’m lucky to be one of them, I started to do ESD in clinical cases when I got the temporary Japanese doctor’s license.
Dr. Ohata is my supervisor and the director of endoscopic center, he is very nice and friendly, who teaches me to determine the individualized ESD treatment according to the gravity direction of lesions for early GI cancer patients hand by hand, is different from some experts need auxiliary traction by dental string, which can reduce the operation time. He teaches me demonstration of different endoscopic devices in detail, such as Dual Knife and Nano IT.
He teaches me lots of tips of ESD, for example, I have learnt to enter endoscope and devices at the same time using my right hand, and learnt to control up/down or left/right button and enter devices at the same time using my left hand by make “Loop” to endoscope, by which I can control the endoscope perfectly and cut the lesions freewheelingly.
There is one thing that impressed me most, it took Director Ohata four hours to do ESD for a Juvenile polyposis patients, the size of the largest LST-G-H lesion I had seen is 155×145 mm, he dissected and cut the nearly circumferential lesions carefully and patiently by making two tunnels, the perfect and successful ESD operation has won everyone’s admiration. His enthusiasm for endoscopy and his pursuit of perfection for ESD technique are always worth learning.
Furthermore, I have made great progress in ESD operation with the guidance and help of Dr. Muramoto, Dr. Chiba, Dr. Ito and Dr. Kanda. Dr. Muramoto and Dr. Minato of Dr. Ohata’s team are engaged in ESD treatment for early duodenal cancer and early hypopharyngeal cancer. The two docotors have the top two ESD operations for early duodenal cancer in Japan. They are skilled, and friendly to visiting doctors.
Future plan
Before leaving, I introduced the clinical situation and scientific research of early GI cancer in our hospital to Dr. Ohata, and sincerely invited him to our hospital for guidance. He appreciated the achievements of our department and expressed his willingness to teach and guide in China. For the future development and cooperation, I hope to keep close contact with Dr. Ohata’s GI endoscopic team and gastroenterology department of NTT Medical Center Tokyo through Email, pay attention to its academic trends, and actively participate in the international events of early gastrointestinal cancer; Also hope that the screening, accurate examination and endoscopic ESD treatment technology of early gastrointestinal cancer in my hospital will be enhanced through the excellent platform of NTT Medical Center Tokyo.
Conclusion
Time has been fleeting in the past eight months. My trip to Tokyo, Japan, has brought me fruitful results, broadened my horizons, enriched my experience, and improved my basic research and endoscopic practice level of early gastrointestinal cancer, which is an unforgettable and forever memorable experience for me. Thank for help of Dr. Ohata, Dr. Muramoto, Dr. Chiba, Dr. Tsuji, Dr. Minato, Dr. Ito, Dr. Sagai, Dr. Konishi, Dr. Kimoto, Dr. Ishii, Dr. Kanda and all the other teachers from Dr. Ohata’s endoscopic team. I look forward to meeting you again soon.