For follicular and papillary thyroid cancer an adjuvant external beam
irradiation after surgery, application of I-131 and TSH-suppression ma
y be indicated for stage T4. The benefit of such a supplementary treat
ment increases, if negative prognostic factors exist, i.e. incomplete
resection, lymph node metastases and patients' age >40 years. Positive
long-term effects concerning survival may be higher in papillary canc
er as compared with follicular cancer. The effectiveness of external i
rradiation for medullary carcinoma is more controversial, published da
ta do not indicate its defined place in the curative treatment. Locali
zed anaplastic thyroid cancer should be treated with combined radio-/c
hemotherapy.