NBI Combined With MRI to Guide CTV Optimization in Eccentric Nasopharyngeal Carcinoma

Inclusion Criteria: 1. Males and females ≥18 years of age; 2. ECOG Performance Status 0,1 or 2; 3. Pathologically diagnosed as nasopharyngeal carcinoma; 4. Pretreatment nasopharynx and neck MRI imaging; 5. Nasopharyngeal suspected lesions were examined by NBI endoscopy; 6. Meeting the definition of eccentric NPC with ipsilateral (affected side) staging of T1-4 and contralateral (healthy side) staging of T0; 7. Patients evaluated without contraindications to radiotherapy; 8. Voluntary participation in clinical research, and signed informed consent. Exclusion Criteria: 1. Patients who did not successfully undergo all three examinations (MRI, NBI, and endoscopic biopsy); 2. Other rare pathological types, such as adenocarcinoma; 3. Patients with tumor invasion of the clivus; 4. Patients whose contralateral retropharyngeal lymph nodes met the diagnostic criteria; 5. Invasion of paranasal sinuses (except simple sphenoid invasion).