1. Department of Radiology Sun Yat‐Sen University Cancer CenterState Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy Guangzhou P. R. China
2. Department of Radiation Oncology Cancer CenterThe First People's Hospital of Foshan Affiliated to Sun Yat‐sen University Foshan P. R. China
3. Cancer Prevention Center Sun Yat‐Sen University Cancer CenterState Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy Guangzhou P. R. China