1. Department of Biostatistics, University of Michigan, Ann Arbor
2. Department of Otolaryngology–Head and Neck Surgery, University of Michigan, Ann Arbor
3. Department of Radiation Oncology, University of Michigan, Ann Arbor
4. Department of Radiology, University of Michigan, Ann Arbor
5. Department of Otorhinolaryngology–Head and Neck Surgery, Erasmus Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands