1. Princess Margaret Cancer Centre, Toronto, ON, Canada;
2. NRG Oncology SDMC/ACR, Philadelphia, PA;
3. Princess Margaret - University Health Network, Toronto, ON, Canada;
4. Jiahui International Cancer Center, Shanghai, China;
5. Mayo Clinic, Jacksonville, FL;
6. Montefiore Einstein Center for Cancer Care, Bronx, NY;
7. New York Presbyterian - Columbia, New York, NY;
8. University of Texas MD Anderson Cancer Center, Houston, TX;
9. Massachusetts General Hospital, Boston, MA;
10. University Health Network, Toronto, ON, Canada;
11. James Cancer Hospital and Solove Research Institute, Columbus, OH;
12. Department of Gastrointestinal Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX;
13. Tom Baker Cancer Centre, Calgary, AB, Canada;
14. London Regional Cancer Centre, London, ON, Canada;
15. Albert Einstein College of Medicine, Bronx, NY;
16. University Hospitals Seidman Cancer Center, and Case Western Reserve University Comprehensive Cancer Center LAPS, Cleveland, OH;
17. NRG Oncology/ SDMC/ACR, Philidelphia, PA;
18. Memorial Sloan Kettering Cancer Center, New York, NY;