1. Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9, Canada
2. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
3. Departments of Surgery (Urology) and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto, Toronto, Ontario M5G 2M9, Canada
4. Pathology Department, University Health Network, Toronto, Ontario M5G 2C4, Canada
5. Radiation Medicine Program, Princess Margaret Hospital, University Health Network and the University of Toronto, Toronto, Ontario M5G 2M9, Canada
6. Radiation Medicine Program, Princess Margaret Hospital, University Health Network and the University of Toronto, Toronto, Ontario M5G 2M9, Canada and Centre Hospitalier de l'Université de Montréal, 1058 Rue Saint‐Denis, Montréal, Québec H2X 3J4, Canada
7. Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48108