1. Henan Provincial Key Laboratory of Radiation Medicine, The First Affiliated Hospital of Zhengzhou University , Zhengzhou , Henan 450052, P.R. China
2. Department of Radiation Oncology, The Sixth Affiliated Hospital, Sun Yat-sen University , Guangzhou, Guangdong 510655, P.R. China
3. GuangDong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University , Guangzhou, Guangdong 510655, P.R. China
4. Academy of Medical Sciences, Zhengzhou University , Zhengzhou, Henan 450052, P.R. China
5. Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University , Zhengzhou, Henan 450052, P.R. China
6. Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University , Guangzhou, Guangdong 510655, P.R. China
7. State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center , Guangzhou, Guangdong 510655, P.R. China
8. Department of Gastroenterology, Hernia and Abdominal Wall Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University , Guangzhou, Guangdong 510655, P.R. China