I-131 therapy of thyroid cancer patients

Thyroid cancer is a rare malignancy with wide interethnic and geographic va riations, In Germany thyroid carcinoma is the 13th most frequent malignancy (2.7 new cases yearly per 100,000 inhabitants). The overall temporal incid ence is increasing slightly in recent years. The most common types of cance r are papillary (60-80%) and follicular cancers (10-20%), The relevant prog nostic indicators are tumor stage and distant metastases, The mean survival rates in papillary thyroid cancer usually exceed 90%, whereas in follicula r thyroid cancer they amount to approximately 80%, The standard treatment p rocedure in differentiated papillary and follicular thyroid cancer consists of total thyroidectomy followed by adjuvant ablative therapy with radioiod ine. Only in papillary thyroid cancer stage PT1N0M0 lobectomy alone is cons idered to be appropriate. In patients with locally invasive differentiated thyroid cancers stage pT4 adjuvant percutaneous radiation therapy is a trea tment option. Radioiodine therapy has to be performed under the stimulative influence of TSH. Usually TSH suppressive medication with Levothyroxine ha s to be withdrawn approximately 4 weeks prior to radioiodine therapy. In th e future, exogenous stimulation by recombinant TSH may be used instead of t hyroid hormone withdrawal It has been proven by different studies that abla tive radioiodine therapy reduces the frequency of recurrences and tumor spr ead in patients with thyroid cancer significantly. In patients with distant metastases, up to 50% of complete responses may be achieved with radioiodi ne treatment.