Thyroid remnant ablation in differentiated thyroid carcinoma: When and how

131I ablation is considered an effective and safe adjuvant therapy modality for differentiated thyroid cancer (DTC), although there is an ongoing debate about the need for 131I ablation in patients without lymph node or distant metastases and with low stages of the primary (pT1-2) tumor. However, on the basis of evidence from retrospective studies and pending the results of ongoing controlled prospective randomized trials, it seems advisable to perform 131I remnant ablation in patients with primary tumors >1 cm. For thyroid remnant ablation, individual dosimetry is not generally considered necessary, but it may improve success rates if used according to strict criteria. The use of recombinant human TSH (rhTSH) for patient preparation allows maintenance of quality of life and results in a lower radiation exposure of healthy non-thyroid tissue compared with TSH stimulation through levothyroxine withdrawal. This approach has been approved for 131I ablation, but not for 131I therapy of distant metastases. © 2013 Italian Association of Nuclear Medicine and Molecular Imaging.