Radiation therapy (RT) plays a key role in curative-intent treatments for head and neck cancers. Its use is indicated as a sole therapy in early stage tumors or in combination with surgery or concurrent chemotherapy in advanced stages. Recent technologic advances have resulted in both improved oncologic results and expansion of the indications for RT in clinical practice. Despite this, RT administered to the head and neck region is still burdened by a high rate of acute and late side effects. Moreover, about 50% of patients with high-risk disease experience loco-regional recurrence within 3 years of follow-up. Therefore, in recent decades, efforts have been dedicated to optimize the cost/benefit ratio of RT in this subset of patients. The aim of the present review was to highlight modern concepts of RT for head and neck cancers considering both the technological advances that have been achieved and recent knowledge that has informed the biological interaction between radiation and both tumor and healthy tissues.

放射疗法（RT）在头颈癌的根治性治疗中起着关键作用。它的使用被指示为在早期肿瘤中的唯一疗法，或与晚期手术或同时进行的化学疗法联合使用。最近的技术进步已导致改善的肿瘤学结果和在临床实践中扩大了RT适应症的范围。尽管如此，急性和晚期副作用的高发生率仍然给头颈部区域的RT带来负担。此外，约有50％的高危患者在随访3年内出现局部复发。因此，在最近的几十年中，一直致力于优化该患者亚组中RT的成本/收益比。