1 Department of Obstetrics and Gynecology, Hebei Yanda Hospital, Langfang, Hebei Province, 065201, PR China. Electronic address: lgt93@126.com.
2 Department of Obstetrics and Gynecology, Hebei Yanda Hospital, Langfang, Hebei Province, 065201, PR China.
3 Departments of Radiation Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, 52 Fucheng Rd, Haidian District, Beijing, 100142, PR China.