1. Department of Radiation Oncology, Dongfang Hospital, Xiamen University, Fuzhou, Fujian 350025, P.R. China
2. Department of Radiation Medicine, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, P.R. China
3. Department of Radiation Oncology, Fuzhou General Hospital of Nanjing Military Command, Fuzhou, Fujian 350025, P.R. China
4. Department of Gynaecology and Obstetrics, Dongfang Hospital, Xiamen University, Fuzhou, Fujian 350025, P.R. China