1. Department of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, P.R. China
2. Department of Radiation Oncology, Liuzhou Worker Hospital, Liuzhou 545000, Guangxi, P.R. China
3. Department of Radiation Oncology, First People’s Hospital of Yulin City, Yulin 537000, Guangxi, P.R. China
4. Department of Radiation Oncology, People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, Guangxi, P.R. China
5. Department of Radiation Oncology, Affiliated Hospital of Guilin Medical University, Guilin 541000, Guangxi, P.R. China
6. Department of Radiation Oncology, Wuzhou Red Cross Hospital, Wuzhou 543000, Guangxi, P.R. China