1. Princess Margaret Cancer Centre, Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
2. Princess Margaret Cancer Centre, Department of Biostatistics, University of Toronto, Toronto, Ontario, Canada
3. Princess Margaret Cancer Centre, Department of Medical Oncology, University of Toronto, Toronto, Ontario, Canada
4. Princess Margaret Cancer Centre, Department of Otolaryngology—Head & Neck Surgery/Surgical Oncology, University of Toronto, Toronto, Ontario, Canada