①目的　研究头颈部癌放疗对甲状腺功能的影响。②方法　对 96例放射治疗头颈部癌病人的甲状腺功能进行了检测。③结果　放疗波及全部甲状腺者放疗后血清总T3 (TT3 )、总T4(TT4)、反T3 (rT3 )值较放疗前下降 ,差异有显著性 (F =4 .92～ 5 .2 3,q =4 .81～ 5 .1 2 ,P <0 .0 5 ) ,且 2年内有 3例发生甲状腺功能减退 (其中 1例为一过性 )。放疗仅波及部分甲状腺者 ,放疗后甲状腺功能无明显改变。④结论　对于头颈部肿瘤病人在行放疗时 ,应尽可能地保护甲状腺组织 ,降低甲状腺功能的损伤程度 ① Objective To study the effect of radiotherapy for head and neck cancer on thyroid function. Methods 96 patients with head and neck cancer radiotherapy for thyroid function were detected. Results The total T3 (TT3), total T4 (TT4) and anti-T3 (rT3) levels of radiotherapy in all thyroid patients after radiotherapy were significantly lower than those before radiotherapy (F = 4.92-5.33, q = 4.81 ~ 5 .1 2, P <0.05), and 3 cases had hypothyroidism within 2 years (1 of them was transient). Radiotherapy only affects part of the thyroid, thyroid function after radiotherapy no significant change. ④ Conclusion for head and neck cancer patients radiotherapy, thyroid tissue should be protected as much as possible to reduce the degree of thyroid function damage