Is There a Role for Peptide Receptor Radionuclide Therapy in Medullary Thyroid Cancer?

Background: Medullary thyroid cancer (MTC) is a rare but potentially life-threatening disease with limited therapeutic options. As a neuroendocrine tumor, MTC expresses somatostatin receptors, and therefore, somatostatin-labeled radiopharmaceuticals could be used to treat patients with MTC. Objective: The aims of this study were to evaluate tumor shrinkage after Lu-177-DOTATATE treatment, to analyze the impact on quality of life as accessed by the SF-36 questionnaire, and to demonstrate a possible prognostic role for In-111-DTPA-octreotide uptake in patients with MTC. Patients and Methods: Patients with progressive MTC underwent evaluation using In-111-DTPA-octreotide. Patients who demonstrated In-111-DTPA-octreotide uptake were treated with 4 cycles of 200 mCi of Lu-177-DOTATATE and were evaluated using CT scans over 8 to 12 months of treatment. Results: Of the 16 patients initially enrolled, 9 (56.25%) had lesions that were observed in the In-111-DTPA-octreotide scans and were eligible for therapy with Lu-177-DOTATATE. Three patients had a partial response, 3 patients were classified as having stable disease and, 1 patient had a progressive disease. All responders indicated improvement in quality of life 6 to 12 months after therapy. Conclusions: Treatment with Lu-177-DOTATATE seems to be an alternative therapy for somatostatin receptor-positive tumors, with very mild adverse effects and quality-of-life improvement, at least during a short-term period. Further studies are needed to determine long-term benefits and to identify which patients are more likely to respond to this modality of therapy.