1. Department of Respiratory Diseases, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
2. Department of Radiation Oncology, Jiangxi Cancer Hospital, Nanchang, Jiangxi 330029, P.R. China
3. Department of Thoracic Oncology, Jiangxi Cancer Hospital, Nanchang, Jiangxi 330029, P.R. China