Intensity-modulated radiotherapy for head and neck cancer.

Intensity-modulated radiation therapy (IMRT) is a new radiation delivery technique that allows more precise delivery of radiation and optimization of the dose intensity to specific volumes while sparing the dose to critical normal structures. Using IMRT in head and neck cancers is attractive because of close proximity of the tumor targets to critical normal structures such as the spine, eyes, and parotid glands. IMRT has been shown in a number of clinical sites to improve local control and decrease side effects. Specifically, IMRT has shown the ability to preserve salivary function through sparing of the parotid glands. At the same time, there remain some uncertainties in terms of target delineation, secondary cancers, and side effects to swallowing function that may be increased with IMRT. Multi-institutional studies of IMRT are under way, and these studies, combined with refinements of the technique, should lead to continued improvement in the radiotherapeutic management of head and neck cancer.