1. University of Texas Southwestern Medical School Dallas Texas U.S.A.
2. Department of Otolaryngology Head and Neck Surgery University of Texas Southwestern Medical Center Dallas Texas U.S.A.
3. Department of Radiation Oncology University of Texas Southwestern Medical Center Dallas Texas U.S.A.
4. Harold C. Simmons Comprehensive Cancer Center University of Texas Southwestern Medical Center Dallas Texas U.S.A.