Occurrence of Radiation-induced Otitis Media in Nasopharyngeal Carcinoma Patients After Intensity Modulated Radiotherapy

Inclusion Criteria: * Age 18-70, regardless of sex. * ECOG (Eastern Cooperative Oncology Group) score: 0-1. * Patients must sign informed consent and be willing, and well understood the objective and procedure of this study. * Patients with newly histologically confirmed non-keratinizing nasopharyngeal carcinoma, type of WHO II or III, clinical stage I-IVa (according to the 8th American Joint Committee on Cancer \[AJCC\] edition. * No radiotherapy or chemotherapy was administered before enrollment. * Expected survival time ≥ 6 months. Exclusion Criteria: * Women in pregnancy or lactation. * Patients with significantly lower heart, liver, lung, kidney, bone marrow function and other severe medical condition. * Prior to radiotherapy, there is a clear underlying disease of the eustachian tube or other ear diseases. * Patients with otitis media before radiotherapy and have no improvement at the end of radiotherapy. * Patients with history of middle ear, nasal or nasopharyngeal surgery on the affected side. * Patients combined with congenital cleft palate and other craniofacial abnormalities. * Patients with histologically confirmed keratinizing nasopharyngeal carcinoma, type of WHO I. * Patients with recurrence and distant metastasis. * Patients with radiotherapy or chemotherapy before. * Age \< 18 or age \> 70. * Patients who changed their initial treatment regimen during the observation period due to disease progression (including tumor residual after radiotherapy, tumor recurrence, and new distant metastases).