1. Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China
2. Department of Radiology, Nanjing Drum Tower Hospital, Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China
3. The Comprehensive Cancer Centre of Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing 210008, China
4. Philips Healthcare, Shanghai 200233, China
5. Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, USA