Submandibular gland-sparing intensity-modulated radiotherapy

Abstract

Xerostomia is one of the most debilitating late effects of head and neck radiotherapy (RT) and significantly impacts quality of life. The submandibular gland (SMG) provides approximately 70% of the unstimulated saliva that accounts for about 95% of the salivary flow during a 24-hour period. Intensity-modulated RT (IMRT) has been used in recent years to lower the RT dose to the parotid gland(s) to reduce long-term xerostomia. There is little experience with SMG-sparing IMRT. Mean RT doses to the SMG exceeding 39 Gy cause permanent ablation of both stimulated and unstimulated salivary flow. Limited data suggest that SMG-sparing IMRT in selected patients results in reduced long-term xerostomia without increasing the risk of a local-regional recurrence.