Assessment of Parotid and Submandibular Glands With Shear Wave Elastography Following Radioactive Iodine Therapy for Papillary Thyroid Carcinoma.

Abstract

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Radioactive iodine (RAI) therapy is used for remnant ablation following thyroidectomy. Side effects such as dysphagia, xerostomia, and sialoadenitis may occur. We aimed to determine the differences in the parotid and submandibulary glands between healthy patients and patients with PTC who had undergone RAI therapy and have dry mouth symptoms using both shear wave elastography and ultrasonography. We enrolled 30 patients with PTC who had undergone RAI therapy following surgery and 30 healthy controls. Ultrasonography and shear wave elastography of submandibular and parotid glands were performed. The volume of the submandibular glands and the thickness of parotid glands were determined. Ten independent measurements were obtained from each gland, with the region of interest placed at different points on the glands. The mean shear wave velocities (SWVs) were calculated and compared between the patients and controls. In the PTC group, there was a significant reduction in the volume of the submandibular glands (P < .05) and in the thickness of the parotid glands (P < .05) compared with the control group. The mean SWVs of the parotid glands and submandibular glands were significantly higher in the PTC group compared with the control group (P < .0001). The SWVs of the parotid glands were higher than the SWVs of the submandibular glands (P < .0001). Shear wave elastography could be a noninvasive and easy assessment method of parotid and submandibular glands in patients who had undergone RAI therapy and experience dry mouth.