Update on iodine-refractory differentiated thyroid carcinoma.

Radioiodine therapy represents a fundamental pillar in the routine adjuvant therapy of patients with high-risk differentiated thyroid carcinoma. However, a non-negligible percentage of these patients will develop iodine refractoriness, showing a worse prognosis, as well a lower survival, which demonstrates a clear need to explore different therapeutic approaches. Iodine refractory patient treatment continues to be a challenge, currently having different novel therapeutic options that should be known by the different specialties related to differentiated thyroid carcinoma (DTC). The aim of this work is to review iodine refractory thyroid carcinoma treatment, focusing especially on the definition of iodine refractoriness, highlighting its importance due to its high mortality, and introducing the different therapeutic options available for these patients.

Use of 177Lu-dotatate in the treatment of iodine refractory thyroid carcinomas. / Uso del 177Lu-DOTATATE como terapia en carcinomas de tiroides yodorrefractarios.

In a patient with a differentiated thyroid cancer the standard treatment protocol to be followed is surgery, ablation of thyroid remnants with 131Iodine (131I), and TSH suppression. However, the treatment with 131I is not effective in some cases, and it no longer becomes a therapeutic option due to cell de-differentiation with loss of 131I uptake. Systemic treatment can be used as other options, although patients are not always responsive; thus, the disease may progress and therapeutic options may run out. Endocrine tumours may express somatostatin receptors,and this characteristic has been used, not only for diagnosis, but also for their treatment through somatostatin analogue labelling with radioactive isotopes. This was the case of a patient suffering from iodine-refractory follicular thyroid carcinoma, with somatostatin receptors expression, treated with 177Lu-DOTATATE, showing an excellent clinical and analytical response.