1. Department of Gastroenterology, Sir Run Run Shaw Hospital, Zhejiang University Medical School, Hangzhou 310016, China
2. Department of Radiation Oncology, The First Affiliated Hospital, School of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou, Zhejiang 310003, PR China
3. Zhejiang University School of Medicine, Hangzhou, Zhejiang, China