Risk-Adapted Omission of Level Va Irradiation in Nasopharyngeal Carcinoma

Inclusion criteria

• Pathologic diagnosis (pathologically confirmed by nasopharyngeal biopsy) was nasopharyngeal carcinoma;
• No distant metastatic;
• Eastern Cooperative Oncology Group (ECOG) score of 0 or 1;
• Signing informed consent;
• Follow up regularly and comply with test requirements.

Exclusion criteria

• Ipsilateral Level IIb involvement;
• Ipsilateral Level III nodes involvement;
• Ipsilateral positive lymph nodes below the cricoid cartilage (Level IV or Vb-c);
• Disease progression during IMRT;
• Previous malignancy or other concomitant malignant diseases;
• The evaluation information of tumor efficacy can not be obtained;
• Receive blind treatment in other clinical research;
• Have or are suffering from other malignant tumors within 5 years (except non- melanoma skin cancer or pre-invasive cervical cancer);
• Serious complications, such as uncontrolled hypertension, coronary heart disease, diabetes, heart failure, etc;
• Active systemic infection;
• No or limited capacity for civil conduct;
• The patient has a physical or mental disorder, and the researcher considers that the patient is unable to fully or fully understand the possible complications of this study;
• Pregnancy or lactation period;