Voxel-based analyse identifies new functional subregions predictive of xerostomia after hoofd-hals cancer radiotherapy

Xerostomia is a common and debilitating toxicity following head and neck cancer (HNC) radiotherapy (RT). Although adaptive radiotherapy (ART) strategies can reduce mean parotid gland (PG) dose, clinical trials have shown limited benefit in reducing xerostomia, suggesting global dose metrics may be insufficient. Voxel-based analysis (VBA) enables assessing local dose–toxicity relationships and may identify symptom-related subregions (SRS) more predictive of toxicity. This study aimed to identify xerostomia-associated SRS using VBA and assess their relevance using a functional salivary atlas.