Peking University - Research Center of Clinical Epidemiology, Fudan University - Huashan Hospital, Tianjin Medical University, Stanford University - School of Medicine, Stanford University - School of Medicine, Peking University - Department of Radiation Oncology, Peking University - Department of Radiation Oncology, Stanford University - School of Medicine, Stanford University - School of Medicine, Fudan University - Huashan Hospital, Peking University - Department of Radiation Oncology, University of Texas at Houston - Department of Radiation Oncology, Peking University - Department of Radiation Oncology, Stanford University - School of Medicine and Peking University - Department of Radiation Oncology