Clinical characteristics of nasolacrimal duct obstruction after iodine therapy of DTC patients

Background: The aim was to analyze clinical characteristics of differentiated thyroid carcinoma (DTC) patients with nasolacrimal duct obstruction after 131 I therapy and provide guidance for clinical decision-making. Methods: : Thirty one DTC patients with nasolacrimal duct obstruction were retrospectively enrolled from the Nuclear Medicine Department of Shanxi Bethune Hospital during follow-up of 131 I therapy between June 2018 and March 2021.Sixty one thyroid cancer patients without nasolacrimal duct obstruction after 131 I therapy were also enrolled to act as a control group. Clinical characteristics, including sex, age, dose, positive anti-thyroglobulin antibodies (TGAb), metastasis and nasal uptake, were analyzed by χ 2 test and logistic multifactor regression. Results: : Statistically significant differences were found in patients’ nasal uptake after 131 I therapy according to gender (11.8% : 38.7%), age (5.6% : 51.1%), dose (3.4% : 47.6%), stage (18.5% : 70.4%) and iodine uptake (83.3% : 30.2%). There was no significant difference in the proportion of TGAb positive and negative patients according to 131 I therapy (χ 2 =0.27, P=0.782). Multivariate logistic regression analysis showed that gender (2.59), age (1.45), dose (2.36), whether there was iodine uptake of metastatic foci (1.93) and whether there was nasal uptake of iodine (1.70) were all statistically significant influential factors of lacrimal discharge symptoms after iodine therapy. Conclusion: Patients who were over 50, women, had metastatic iodine uptake, received a dose > 5.55GBq and had nasal intake of 131 I were more likely to have nasolacrimal duct obstruction. When determining therapeutic doses of 131 I, doctors should weigh multiple factors and suggest that high risk populations be referred to the appropriate ophthalmic surgery for timely diagnosis and therapy.