1. Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
2. Albert Einstein College of Medicine, Bronx, NY, USA
3. These authors contributed equally to this work.
4. Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada
5. Department of Radiation Oncology, Fujian Provincial Cancer Hospital, Provincial Clinical College, Fujian Medical University, Fuzhou, Fujian, China
6. Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
7. University of Texas Southwestern Medical Center, Dallas, TX, USA
8. Department of Medicine, Head and Neck Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
9. Procure Proton Therapy Center, Somerset, NJ, USA