1. Head and Neck Institute Cleveland Clinic Cleveland OH USA
2. Taussig Cancer Institute, Cleveland Clinic Cleveland OH USA
3. Department of Radiation Oncology Memorial Sloan Kettering Cancer Center New York NY USA
4. Department of Radiation Oncology Henry Ford Hospital Detroit MI USA
5. Department of Radiation Oncology Moffitt Cancer Center Tampa FL USA
6. Department of Radiation Oncology University of Louisville School of Medicine Louisville KY USA
7. Department of Radiation Oncology Princess Alexandra Hospital/University of Queensland Brisbane QLD Australia