Phase II, single-arm, prospective clinical study of Toripalimab(a PD-1 antibody) combined with radiotherapy and chemotherapy in the treatment of sinonasal malignant mucosal melanoma after endoscopic surgery.

Inclusion Criteria:

1.Pathologically diagnosed as sinonasal malignant mucosal melanoma, locally resectable and no contraindication for surgery or radiation. 2.T3 and T4. 3.Age ≥18 year-old 4.No distant metastasis 5.No head and neck radiation and systemic anti-tumor therapy performed in the past 5 years. 6.The performance status of the Eastern Cooperative Oncology Group(ECOG) is 0-2 points and surgery after general anesthesia and postoperative radiation could be tolerated. 7.Accepted organ function

Exclusion Criteria:

1. Patients who refused to sign informed consent. 2. Have received radioactive seed implantation in the treatment area. 3. Suffer from uncontrolled disease which could interfere treatment. 4. Suffered from another malignant tumor or multiple primary tumors at the same time within 5 years (excluding fully treated basal cell or squamous cell skin cancer, cervical cancer in situ, etc.). 5. The patient has surgical contraindications: such as severe cardiopulmonary disease, coagulation dysfunction and so on. 6.The patients have autoimmune diseases. 7. The patient is using immunosuppressive agents or systemic hormone therapy to achieve the purpose of immunosuppression (dose>10mg/day prednisone or other curative hormones), and continues to use it within 2 weeks before the first administration; 8. Severe allergic reaction to other monoclonal antibodies; 9. Previously received PD-1 monoclonal antibody, CTLA-4 monoclonal antibody (or any other antibody that acts on T cell co-stimulation or checkpoint pathway) treatment; 10. Live vaccines have been inoculated within 4 weeks before the first administration or during the study period; 11. The patient has any situation that may hinder study compliance or the safety during the study period.12. Existence of serious neurological or psychiatric diseases, such as dementia and seizures; 13. Uncontrolled active infection. 14. Pregnant or breastfeeding women. 15. Those who have no personal freedom and independent capacity for civil conduct;p. 16. There are other situations that are not suitable for entry into the study.