Concurrent Immunotherapy With Postoperative Radiotherapy in Intermediate/High Risk HNSCC Patients Unfit for Cisplatin: The IMPORT Study (IMPORT)

Inclusion Criteria: * 1\. Histologically confirmed squamous cell carcinoma of the head and neck.Site of tumor origin in the oral cavity, oropharynx, larynx, hypopharynx , or sinuses (excluding nasopharynx) 2. With at least one risk factors after radical surgery ①positive margin; ②close margin（\<5mm); ③ENE;④PNI;⑤LVI; ⑤ pT3-4/N2-3( AJCC 8th).⑥ Level IV/V lymph node metastases for OPC or OC. 3\. Have at least one contraindication to cisplatin as defined: ① Age\>65 years old; ②Creatinine clearance (CC) \> 30 and \< 60 cc/min For this calculation, use the Cockroft-Gault formula: CC = 0.85 (if female)\* ((140-Age) / (Serum Creatinine)) \* (Weight in kg / 72); ③ Zubrod performance status 2; ④Pre-existing peripheral neuropathy grade ≥ 1; ⑤History of hearing loss, defined as either: ▪ Existing need of a hearing aid OR ≥ 25 decibel shift over 2 contiguous frequencies on a pretreatment hearing test as clinically indicated. 4\. No distant metastases 5. No synchronous or concurrent head and neck primary tumors 6. ECOG PS 0-2 7. Adequate organ function including the following: 1. Absolute neutrophil count (ANC) \>= 1.5 \* 10\^9/l 2. Platelets count \>= 80 \* 10\^9/l 3. Hemoglobin \>= 80 g/dl 4. AST and ALT \<= 2.5 times institutional upper limit of normal (ULN) 5. Total bilirubin \<= 1.5 times institutional ULN 6. Creatinine clearance \>30 ml/min 8. Signed written informed consent Exclusion Criteria: 1. Prior chemotherapy or anti-cancer biologic therapy for any type of cancer, or prior radiotherapy to the head and neck region 2. Other previous cancer, except for in situ cervical cancer and cutaneous basal cell carcinoma 3. Pregnant or breast-feeding females, or females and males of childbearing potential not taking adequate contraceptive measures 4. Uncontrolled concomitant illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, or cardiac arrhythmia 5. Active, known or suspected autoimmune disease such as interstitial pneumonia, uveitis, Crohn's disease, autoimmune thyroiditis. Subjects with cured childhood asthma, type I diabetes mellitus and hypothyroidism only requiring hormone replacement, or skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment 6. Using systemic immunosuppressive agents and continue the dose within 2 weeks prior to the enrollment;