1. Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA
2. Northwestern Medicine Cancer Center Warrenville, Warrenville, IL 60555, USA
3. Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
4. McGill University Health Centre, Montreal, QC H4A 3J1, Canada
5. Cleveland Clinic Foundation, Cleveland, OH 44195, USA
6. Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
7. Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110, USA
8. National Cancer Institute, Bethesda, MD 20892, USA
9. Stanford Cancer Institute, Stanford, CA 94305, USA
10. Saint Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA
11. UPMC-Shadyside Hospital, Case Western Reserve University, Pittsburgh, PA 15232, USA
12. Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA 19107, USA
13. Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
14. UT Southwestern, Simmons Cancer Center, Dallas, TX 75235, USA
15. Baptist Comprehensive Cancer Center, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
16. Miami Cancer Institute, Miami, FL 33176, USA