Exploring a non-invasive and objective method for ultra early quantitative assessment of radiation-induced parotid gland injury. To provide a new and early method for evaluating changes in parotid gland function in clinical practice, and to guide the timing of interventions to protect the parotid gland.

Exploring the application value of magnetic resonance fingerprinting (MRF) and intravoxel incoherent motion (IVIM) techniques in dynamically monitoring parotid gland injury and predicting the risk of dry mouth after radiotherapy for head and neck tumors. The study evaluated the changes in parotid gland cell density and microcirculation function by quantifying MRF (T1/T2 relaxation time, proton density) and IVIM parameters (D value, D * value, f value), combined with parotid gland volume reduction rate, to establish an early risk model for predicting dry mouth syndrome and optimize parotid gland protection strategies.

Exclusion Criteria:

1. Contraindications to MRI, such as metallic implants or claustrophobia.
2. Severe comorbid conditions, including significant renal or hepatic dysfunction.
3. Concurrent participation in another interventional clinical trial.
4. Pregnant or breastfeeding.
5. Any condition that may impair compliance with study procedures.

Inclusion Criteria:

1. Histologically or cytologically confirmed diagnosis of nasopharyngeal carcinoma.
2. Scheduled to undergo radiotherapy as part of standard treatment.
3. Aged 18 years or older.
4. No contraindications to MRI scans (e.g., no implanted metallic devices).
5. Written informed consent has been provided.

The study population consists of adult patients (18 years of age or older) who have been diagnosed with a head and neck tumour and are planning to receive radiotherapy as part of their standard treatment. Recruitment will take place at the Department of Radiotherapy, Hainan Provincial People's Hospital. Applicants must be able to undergo an MRI scan and provide informed consent.