头颈癌患者放疗（化疗）后味觉障碍的预防性干预 (DYSGRAD)

实验性的：实验组

4次味觉障碍干预疗程和6次评估疗程

行为的：Prophylactic dysgeusia intervention

The prophylactic dysgeusia intervention consists of one 30-minute weekly session and includes:

1. Oral hygiene assessments: questionnaire and clinical inspection to ensure a healthy oral environment, a prerequisite for the remainder of the protocol.
2. Salivary gland massages: gentle stimulation of the parotid, submandibular, and sublingual glands to increase salivation and enhance taste perception.
3. Intraoral cryotherapy: placement of an ice cube in the mouth to provide hydration, reduce mucositis, and improve oral sensitivity.
4. Taste trainings: recognition of four tastes (sweet, bitter, sour, salty) with an accompanying questionnaire.

无干预：Control group

5 evaluation sessions

Quantitative taste perception

The primary outcome is the change in quantitative taste perception from baseline to each follow-up evaluation.

Taste perception is assessed using a 10-point Likert-scale-based gustatory evaluation, measuring perceived taste modalities (sweet, salty, bitter, and sour).

The primary endpoint is defined as the presence or absence of improvement relative to baseline, assessed at Evaluation 2 (end of the intervention, corresponding to week 3 of radiotherapy), Evaluation 3 (1 month after completion of radiotherapy), Evaluation 4 (3 months after completion of radiotherapy), and Evaluation 5 (6 months after completion of radiotherapy).

Dysgeusia score according to the Common Terminology Criteria for Adverse Events (CTCAE) scale

Clinical toxicity grade of dysgeusia, assessed using the Common Terminology Criteria for Adverse Events (CTCAE) scale, graded from 1 (least severe) to 5 (most severe)

Sialometry

Salivary function, assessed using sialometric examination

European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-HN43)

Health-related quality of life will be assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-HN43), administered in accordance with European Organisation for Research and Treatment of Cancer (EORTC) scoring guidelines, with scores ranging from 0 to 100. Scores range from 0 to 100, with higher scores indicating greater symptom burden or functional impairment, depending on the subscale.