ABSTRACT
The parotid glands are the major salivary glands, and associated injuries following head and neck cancer radiotherapy (RT) are primarily attributed to insufficient salivary production that is xerostomia. The rate of xerostomia after intensity modulated radiation therapy may be significantly lower compared to that after three-dimensional conformal RT. Xerostomia has primarily been modeled using parotid mean doses. Focusing in addition on an inter-organ interplay while simultaneously incorporating patient and treatment factors, and spatial patterns should be a goal of future dose-response efforts. For late xerostomia, a tendency of contralateral dose-gradients in the left-right direction as well as in the antero-posterior direction was observed, but only for long-term xerostomia a significant relationship was found. Xerostomia typically peaks within a one year window after completed RT, and is often, though not always, followed by significant recovery of capac.
