1. Division of Hepatobiliary and Pancreatic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
2. Department of Thoracic Surgical Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
3. Department of Hepato-Biliary-Pancreatic Medicine, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
4. Department of Surgery, Albany Medical Center , Albany, New York , USA
5. Department of Diagnostic Imaging, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
6. Department of Hepatobiliary-Pancreatic Surgery, Juntendo University School of Medicine , Tokyo , Japan