1. Department of Oncology, The Changzhi People's Hospital, Changzhi, Shanxi 046000, P.R. China
2. Department of Radiotherapy, The 264th Hospital of Chinese People's Liberation Army, Taiyuan, Shanxi 030001, P.R. China
3. Medical Department, The Changzhi People's Hospital, Changzhi, Shanxi 046000, P.R. China