[1] United Christian Hosp, Dept Clin Oncol, Hong Kong, Peoples R China
[2] Sunnybrook Hlth Sci Ctr, Odette Canc Ctr, Toronto, ON, Canada
[3] Inst Canc Res, Canc Risk Factors & Lifestyle Epidemiol Unit, Prevent & Clin Network, Florence, Italy
[4] Tuen Mun Hosp, Clin Oncol Dept, Hong Kong, Peoples R China
[5] Natl Univ Singapore Hosp, Dept Radiat Oncol, Singapore, Singapore
[6] Hosp Sirio Libanes, Radiat Oncol Div, Sao Paulo, Brazil
[7] Princess Margaret Hosp, Dept Clin Oncol, Hong Kong, Peoples R China