ABSTRACT
The proximity of head and neck cancers (HNCs) to a number of normal structures presents a considerable challenge for their treatments, both for surgical and for radiation therapy approaches. The effectiveness of treatments for HNC is often limited by the side effects they cause in the normal tissues and; therefore, efforts to increase the aggressiveness of the therapeutic approaches have to be balanced against the toxicity they will cause. Toxicity concerns the symptomatic changes caused in normal tissues by the treatment. This chapter will review the types of toxicity that may be encountered from HNC treatment, their modification with changes in therapeutic approaches, and the tolerance doses that may be used for guidance in radiation therapy.
