The effect of head and neck irradiation on taste dysfunction: a prospective study

Area of Science:

• Oncology
• Radiotherapy
• Sensory Science

Background:

• Taste loss and xerostomia are significant morbidities for patients receiving head and neck irradiation.
• Understanding the relationship between radiation dose distribution and these side effects is crucial for patient care.

Purpose of the Study:

• To investigate the correlation between the volume of tongue and parotid glands within the radiation treatment field and the degree of taste loss and xerostomia in head and neck cancer patients.
• To explore factors influencing taste recovery post-radiotherapy.

Main Methods:

• A prospective study involving 26 patients undergoing head and neck irradiation.
• Assessment of taste loss using subjective questionnaires and objective taste testing with serial dilutions of taste solutions.
• Measurement of xerostomia via patient questionnaires.
• Determination of the volume of tongue and parotid glands within the high-dose radiation field for each patient.

Main Results:

• Both objective and subjective taste loss showed a significant association with the proportion of the tongue within the radiation field (r = 0.59 and r = 0.78, respectively; P < 0.002).
• No significant relationship was found between the irradiated volume of the parotid gland and taste loss.
• Changes in xerostomia were significantly correlated with the proportions of both tongue (r = 0.54; P = 0.004) and parotid (r = 0.82; P = 0.0001) within the radiation fields.

Conclusions:

• The proportion of tongue irradiated is a key factor in both objective and subjective taste loss following head and neck radiotherapy.
• While parotid gland irradiation significantly impacts xerostomia, it does not appear to directly influence taste loss.
• Limited evidence suggests that specific radiotherapy techniques, like the wedge pair technique, might aid in subjective taste recovery by sparing the contralateral tongue.