An Evanishing Thyroid During Immune Checkpoint Inhibitor Therapy.

ABSTRACT In recent years, a large number of articles have described the endocrine-related adverse events associated with immune checkpoint inhibitors, especially affecting the thyroid. A 37-year-old man affected by nasopharyngeal carcinoma (stage IVb) underwent serial 18F-FDG PET/CT evaluations during treatment with nivolumab (480 mg every 4 weeks) after first-line chemoradiotherapy. The patient had no history of thyroid disease and before starting immunotherapy the thyroid-stimulating hormone value was normal at 0.9 mU/L (reference range, 0.27-4.2 mIU/L). FDG PET/CT studies revealed involution of the thyroid gland following immune checkpoint inhibitor-induced thyroiditis.