[External radiation therapy for thyroid disease].

The external beam irradiation plays a very important role in the treatment of some thyroid diseases, such as primary cancers (papillary, follicular, medullary and anaplastic), malignant lymphoma and bone metastasis. The treatment policies, the irradiation techniques and the treatment results of these diseases are described from our experiences and the literature. The recent improvements of irradiation techniques are also explained.