Treatment of malignant thyroid disease.

Surgery is the primary form of therapy in the management of malignant thyroid disease. A near-total thyroidectomy is the preferred approach. Radioactive iodine is used for supplementary ablation therapy and for definitive therapy in differentiated tumors of papillary or follicular cell type. Thyroid-stimulating hormone (TSH) is administered in conjunction with radioactive iodine therapy, since tumor uptake appears to be directly related to endogenous TSH levels. Therapeutic doses of radioactive iodine range from 100 to 200 mCi of 131 I depending on tumor distribution. Adequate thyroid hormone replacement therapy resulting in the suppression of TSH is of considerable value in the prevention of tumor recurrence. Due to the possibility of late recurrence, patients should be followed for indefinite periods by means of diagnostic imaging studies at 1-2 yr intervals. Despite 30 yr of experience, the therapeutic efficacy of radioactive iodine remains controversial. However, in recent years, there has been mounting evidence indicating increased survival and decreased tumor recurrence in radioactive iodine-treated patients. External radiation therapy is reserved for anaplastic carcinoma and lymphoma, and adenocarcinomas that are refractory to radioactive iodine. Chemotherapy experience is limited; however, some reduction in the size of metastatic lesions has been observed after the administration of adriamycin.