Radiation-induced Xerostomia: Evaluation with ¹⁸F-FDG PET/CT

Area of Science:

• Oncology
• Radiotherapy
• Nuclear Medicine

Background:

• Xerostomia (dry mouth) is a common side effect of radiotherapy for head and neck cancers.
• Advanced radiation therapy techniques aim to minimize salivary gland damage, but xerostomia persists.
• Assessing salivary gland function and its relationship with radiation dose is crucial for managing treatment toxicity.

Purpose of the Study:

• To investigate the link between radiation dose, metabolic changes in salivary glands using 18F-FDG PET/CT, and xerostomia severity.
• To explore the utility of PET-derived biomarkers in predicting salivary dysfunction.

Main Methods:

• Retrospective analysis of 107 head and neck cancer patients treated with intensity-modulated or volumetric modulated arc therapy.
• Evaluation of clinical xerostomia severity, radiation dose-volume parameters, and metabolic changes (ΔSUVmax, ΔSUVmean) from pre- and post-treatment PET/CT scans.

Main Results:

• Moderate-to-severe xerostomia affected 63.6% of patients.
• Higher tumor stage and nodal metastases were associated with increased xerostomia severity.
• Dose-volume parameters and ΔSUV values correlated significantly with xerostomia, with parotid glands showing greater dose-dependent metabolic decline.

Conclusions:

• 18F-FDG PET/CT effectively captures radiation-induced salivary gland impairment and correlates with xerostomia.
• PET-derived biomarkers offer complementary insights into salivary dysfunction prediction beyond traditional dosimetry.
• Tumor burden also influences xerostomia risk, highlighting the multifactorial nature of this toxicity.