1 Department of Radiation Oncology (Kwan, Tsao, Barnes), University of Toronto; Department of Radiation Oncology (Tsao, Barnes), Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ont.
2 Department of Radiation Oncology (Kwan, Tsao, Barnes), University of Toronto; Department of Radiation Oncology (Tsao, Barnes), Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ont. toni.barnes@sunnybrook.ca.