Inclusion Criteria:

1. Patients with staging Ⅱ-Ⅲ of NPC;

2. Patients who had completed concurrent of radiotherapy and chemotherapy;

3. Patients who have a life expectancy of at least 12 weeks;

4. Eastern Cooperative Oncology Group (ECOG) performance status was 0-1;

5. The bone marrow functioned normally (WBC > 4.0×109/L, Hb > 120 g/L, PLT > 100×109/L);

6. The ECG results were normal, and the liver and kidney were functional.

Exclusion Criteria:

1. Patients who had distant metastases by imaging studies;

2. Patients with uncontrolled infection; underlying disease that was severe or
life-threatening;

3. Patients who were pregnant or lactating;

4. ECOG perform status ≥ 2;

5. Patients who are suffering from auto immune diseases or patients who need to accept
glucocorticoid treatment.