[1] Chongqing Med Univ, Affiliated Hosp 1, Dept Oncol, Chongqing, Peoples R China
[2] Royal Marsden Hosp, Head & Neck Unit, London, England
[3] Inst Canc Res, Div Radiotherapy & Imaging, London, England
[4] Chongqing Med Univ, Affiliated Hosp 1, Dept Oncol, Youyi Rd 1, Chongqing 400016, Peoples R China