1. First Clinical Medical College; Lanzhou University; Lanzhou City, Gansu Province China
2. Department of Thoracic Surgery, The Second Affiliated Hospital of Lanzhou University; Lanzhou University; Lanzhou City, Gansu Province China
3. Evidence-Based Medicine Center, School of Basic Medical Sciences; Lanzhou University; Lanzhou City China
4. Department of Radiotherapy; People’s Hospital of Gansu Province; Lanzhou City, Gansu Province China