68Ga-DOTA-FAPI-04 PET/CT Imaging in a Case of Radioactive Iodine-Induced Chronic Parotitis.

68Ga-DOTA-FAPI-04 is a promising PET agent for tumor imaging. However, inflammatory lesions can also show increased FAPI uptake. Herein, we reported a 52-year-old woman who underwent total thyroidectomy for thyroid papillary carcinoma 1 year ago and underwent adjuvant radioiodine therapy 1 month later. After 131I therapy, she began to develop pain and swelling in bilateral cheeks, which developed into oral dryness. The patient was diagnosed with radioactive iodine-induced parotitis. 68Ga-DOTA-FAPI-04 PET/CT showed the density of bilateral parotid glands increased, and the volume decreased with intense tracer uptake. 99mTcO4- salivary gland scintigraphy showed decreased tracer uptake in the bilateral parotid glands.