• The patient was histologically or cytologically diagnosed with nasopharyngeal carcinoma;

• The patient was newly diagnosed with metastatic nasopharyngeal carcinoma (AJCC eighth edition), and after 4-6 cycles of gemcitabine plus cisplatin combined with PD-1 monoclonal antibody regimen, the efficacy reached more than stable disease;

• Except for the primary tumor and cervical lymph node metastasis, less than 5 distant organ metastases, and were suitable for SBRT radiotherapy;

• ECOG PS score 0-2 points;

• Aged 18-70 years old;

• Major organ function met the following criteria (14 do not allow the use of any blood components and cell growth factor):

‣ Neutrophil ANC ≥ 2.0 × 10\^9/L; platelet count PLT ≥ 100 × 10\^9/L; hemoglobin HB ≥ 90 g/L;

⁃ Serum albumin ≥ 28 g/L;

⁃ Alanine aminotransferase ALT, aspartate aminotransferase AST ≤ 2.5 × ULN; if there is liver metastasis, ALT and AST ≤ 5 × ULN;

⁃ Serum creatinine ≤ 1.5 × ULN, Or creatinine clearance ≥ 60 mL/min;

⁃ INR ≤ 1.5 × ULN, and APTT ≤ 1.5 × ULN;

• Life expectancy ≥ 12 weeks;

• The subject who voluntarily joins the study, sign informed consent, and coordinates with follow-up.