Clinical manifestations of I-131 induced salivary gland dysfunction in patients with thyroid carcinoma

Aim: To carry out a retrospective analysis of the frequency and severity of clinical signs of radioiodine (131I)-induced damage to the salivary glands in the early and long-term post-radiation periods, and identify risk factors for their occurrence in patients with differentiated thyroid carcinomas. Methods: A total of 330 patients underwent thyroidectomy with dissection of lymphatic nodes. One month after surgery, all the patients received radioiodine therapy. The dose and number of courses varied depending on the stage and morphological type of the tumor. In the late post-radiation period, the patients were surveyed with the use of a standard questionnaire, which allowed retrospective assessment of the nature and severity of symptoms of radiationinduced damage, as well as the time of their onset/subsidence. Results: Radiation-induced sialoadenitis of the salivary glands was observed in 51.2% of patients treated with 131I. The main symptoms included pain and discomfort in the salivary glands (51.2% of patients), swelling (48.8%), transient or permanent dry mouth (38%), and distortion of taste (38%). There were statistically significant correlations between the presence and severity of the main clinical symptoms of salivary gland irradiation. A significant relationship (r = 0.91, p < 0.001) was found between swelling of the salivary glands and the feeling of pain or discomfort, which was indicative of inflammation and retention of saliva. Conclusion: The main factors influencing the formation of chronic radiation-induced sialoadenitis and the severity of the inflammatory process included the tumor stage, the total dose of radiopharmaceuticals, and the duration following radioiodine therapy.