1. Department of Radiation Oncology, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, P.R. China
2. Department of Radiation Oncology, Cancer Center of Guangzhou Medical University, Guangzhou, Guangdong 510120, P.R. China
3. Department of Thoracic Surgery, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, P.R. China