1. Division of Research and Development for Minimally Invasive TreatmentCancer CenterKeio University School of MedicineTokyoJapan
2. Division of Gastroenterology and HepatologyDepartment of Internal MedicineKeio University School of MedicineTokyoJapan
3. Medical Education CenterKeio University School of MedicineTokyoJapan
4. Center for Diagnostic and Therapeutic EndoscopyKeio University School of MedicineTokyoJapan