1. Proton Therapy Center, Department of Radiation Oncology, Corewell Health William Beaumont University Hospital, Royal Oak, MI, USA
2. Department of Mathematics, The Hong Kong University of Science and Technology, Hong Kong SAR, PR China
3. Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
4. Molecular Imaging, Radiotherapy and Oncology (MIRO), UCLouvain, Belgium
5. School of Mathematics and Statistics, and Hubei Key Laboratory of Computational Science, Wuhan University, Wuhan, PR China