1 Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada.
2 McGill University Health Centre, Montreal, Quebec, Canada.
3 BC Children's Hospital, Vancouver, British Columbia, Canada.
4 Division of Radiation Oncology, University of Alberta, Edmonton, Alberta, Canada.
5 Canadian Association of Provincial Cancer Agencies, Toronto, Ontario, Canada.
6 Saskatchewan Cancer Agency, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
7 Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia, Canada.
8 Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. Electronic address: derek.tsang@rmp.uhn.ca.