Protection of salivary function by intensity-modulated radiation therapy in patients with head and neck cancer

Abstract

The degree of xerostomia has been reported to depend on the radiation dose and the salivary gland volume irradiated. Sparing salivary function can be achieved by reducing radiation dose to the salivary glands or using a radiation protector, such as amifostine (Ethyol). In this report, the author reviews clinical experiences in intensity-modulated radiation therapy (IMRT) for head and neck cancer. In experiences, the dosimetric advantage of IMRT did translate into significant reduction of late salivary toxicity in patients with oropharyngeal carcinoma. The author has found no adverse impact on tumor control and disease-free survival in patients treated with IMRT. Further, when studying the dose response of parotid gland after irradiation, it was found that the stimulated saliva flow 6 months after IMRT treatment reduced at approximately 4% per Gy exponentially of the mean parotid dose. The authors also review existing clinical data on the combination of amifostine and radiation and the potential therapeutic gain in combining IMRT with amifostine.