Inclusion Criteria:  Histological diagnosis of squamous cell carcinoma of oropharynx with IHC p16 positive or PCR HPV16 positive T1-2/N1-3M0（except T1N1M0 and single LN<3cm）or T3-4N0-3M0 according to UICC/AJCC 8th staging system Age ≥18 No prior anti-tumor treatment Karnofsky Performance Score (KPS)≥70 Adequate blood supply Informed consent obtained  Exclusion Criteria:  Cannot take contrast-MRI imaging Pregnant Combined with other malignant tumor (except basal cell carcinoma of skin)