1. Department of Hepatobiliary and Pancreatic Surgery, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
2. Department of Gastroenterological Surgery II, Hokkaido University Faculty of Medicine, Sapporo 060-8638, Japan
3. Department of Medical Oncology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
4. Department of Diagnostic Imaging, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan