Treatment of Metastatic Thyroid Cancer with Radioiodine Following Preparation by Recombinant Human Thyrotropin

Complete eradication of metastatic thyroid carcinoma is difficult to achieve. This challenge is attributed to (1) the reduction in iodine uptake by thyroid cancer cells, (2) the relatively slow and unpredictable rate of progression, and (3) the generally high quality of life (QOL), even in patients with widely metastatic disease. Furthermore, relatively few studies have identified reliable predictors of the progression rate, the pattern of metastatic spread, or the sensitivity to 131I therapy. Patients and their physicians often continue to administer large amounts of 131I to lesions that appear iodine-avid, even in the absence of previous tumor responses. A common rationalization for this approach is that tumor progression would have been worse if another dose of 131I had not been administered.