Ott_a_201421 3919..3931

1Department of Radio Oncology, The First Affiliated Hospital of Xi’an Jiaotong University School of Medicine, Xi’an, Shaanxi Province, 710061, People’s Republic of China; 2Department of Radio Oncology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, 116027, People’s Republic of China; 3Department of Medical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University School of Medicine, Xi’an, Shaanxi Province, 710061, People’s Republic of China; 4Department of Oncology, The Xi’an Chest Hospital, Xi’an, Shaanxi Province, 710000, People’s Republic of China; 5Department of Radio Oncology, The People’s Hospital of YangZhong City, YangZhong, Jiangsu Province, 212200, People’s Republic of China