Evaluation of Salivary Gland Dysfunction Using Salivary Gland Scintigraphy in Sjögren's Syndrome Patients and in Thyroid Cancer Patients after Radioactive Iodine Therapy.

Abstract

Salivary gland scintigraphy (SGS) provides an objective means of diagnosing salivary gland dysfunction in Sjögren's syndrome (SS) patients and in thyroid cancer patients after radioactive iodine (RAI) therapy. In the present study, SGS was performed in SS patients and in thyroid cancer patients post-RAI, and scintigraphic parameters were compared. Twenty-eight SS patients (males:females = 1:27, age 53.3 ± 11.9 years), 28 controls (males:females = 3:25, age 54.1 ± 10.1 years), and 92 thyroid cancer patients (males:females = 28:64, age 46.2 ± 12.9) who had undergone a session of high-dose RAI therapy (mean dose, 5.2 ± 1.5GBq) were included. SGS was performed using Tc-99m pertechnetate (925MBq). Scintigraphic parameters (parotid uptake ratio PU, submandibular uptake ratio SU, percentage parotid excretion %PE, and percentage submandibular excretion %SE) were measured and compared for SS, thyroid cancer post-RAI, and control patients. PU, SU, %SE, and %PE were all significantly lower in SS than in post-RAI thyroid cancer or control patients (p < 0.05), whereas only %PE was significantly lower in post-RAI thyroid cancer patients than in controls (p < 0.05). SU and %SE were found to be correlated with the unstimulated whole salivary flow rate. Scintigraphic parameters derived from SGS can play a crucial role in the detection of salivary gland dysfunction in SS patients and in post-RAI thyroid cancer patients.