1. Department of Radiation Oncology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
2. Department of Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
3. Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China