1. Department of Clinical Oncology, The First People’s Hospital of Yueyang, No. 39 of Dongmaoling Road, Yueyang, Hunan Province 414000, P. R. China
2. Department of Head and Neck Oncology, The Second Affiliated Hospital of Zunyi Medical University, No. 149 Dalian Road, Zunyi, Guizhou Province 563000, P. R. China