This is an observational cohort study aimed to explore the changes of olfactory function at multiple time points from baseline to 1 year after radiotherapy among the local advanced nasopharyngeal carcinoma patients.

Newly-diagnosed patients with stage III or IV non-metastatic Nasopharyngeal Carcinoma (AJCC 8th) will be recruited. Olfactory function of consecutive patients with nasopharyngeal carcinoma was assessed prospectively before treatment and serially up to 1 year after radiotherapy by the Sniffin' Sticks olfactory function test and by The Questionnaire of Olfactory Disorders (QOD) as well as a patient symptom visual analogue scale. The change in olfactory function and it's influence factors in NPC patients who receiving induction chemotherapy with concurrent chemoradiotherapy will be investigated.

Inclusion Criteria:

• Age 18-70, regardless of sex.
• Patients with newly histologically confirmed non-keratinizing nasopharyngeal carcinoma, type of WHO II or III, clinical stage III-IVa (according to the 8th American Joint Committee on Cancer [AJCC] edition).
• ECOG (Eastern Cooperative Oncology Group) score: 0-1.
• Patients receiving induction chemotherapy with concurrent chemoradiotherap.
• Patients must sign informed consent and be willing, and well understood the objective and procedure of this study.

Exclusion Criteria:

• Women in pregnancy or lactation.
• Patients who received additional treatment during the observation period due to disease progression.
• Patients with significantly lower heart, liver, lung, kidney and bone marrow function.
• Patient with severe medical condition.
• with a condition that could cause olfactory dysfunction, such as septum deviation, nasal polyposis, nasopharyngeal necrosis, congenital olfactory dysfunction, septum surgery, head trauma, chronic rhinosinusitis, allergic rhinitis, or psychiatric or neurological disorders, such as Parkinson's, MS and Alzheimer's disease, or long history of psychiatric drug, corticosteroids or other drug that may affect olfactory function.
• Not able to return for evaluation of olfactory function or follow-up (language, practical implementation, mental condition)

nasopharyngeal carcinoma patients