Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Correspondence to Edward Chow, Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto ON M4N 3M5, Canada. Tel: +1 416 480 4974; fax: +1 416 480 6002; e-mail: [email protected]