Factors Associated With Radioactive Iodine Therapy-Acquired Nasolacrimal Duct Obstruction

Endocr Pract. 2022 Dec;28(12):1210-1215. doi: 10.1016/j.eprac.2022.08.006. Epub 2022 Aug 13.

Abstract

Objective: To identify factors associated with radioactive iodine (RAI)-acquired nasolacrimal duct obstruction (NLDO).

Methods: Retrospective chart review and telephone surveys of patients who received RAI therapy for thyroid carcinoma at an academic institution were conducted. Telephone surveys were used to screen for post-RAI NLDO diagnoses. Databases were reviewed for documented NLDO, demographics, RAI dose, total number of RAI treatments, and sialadenitis. Routine post-RAI whole-body scintigraphy (WBS) images were analyzed for the presence or absence of 131I sodium iodide (I-131) in the nasolacrimal duct. Intranasal I-131 activity was graded as none, low, moderate, and high; those with moderate or high activity were considered to have "increased" activity. Logistic and ordinal logistic regression models were used to evaluate the associations with NLDO while adjusting for I-131 dose.

Results: Of the 209 patients who completed the survey, 15 (7%) had NLDO diagnoses. Increased intranasal I-131 activity on WBS, presence of nasolacrimal I-131 WBS activity, presence of documented post-RAI sialadenitis, and history of >1 RAI treatment were associated with the development of NLDO from univariate analyses (P ≤ .013). After adjusting for the administered dose of I-131, the presence of sialadenitis and nasolacrimal I-131 activity on WBS were the remaining 2 factors significantly associated with NLDO development (P < .001 and P = .01, respectively).

Conclusions: The presence of sialadenitis and nasolacrimal I-131 activity on WBS are I-131 dose-independent correlative factors for RAI-associated NLDO. Patients with these characteristics should be counseled on their increased risk of NLDO after RAI therapy for thyroid carcinoma.

Keywords: epiphora; nasolacrimal duct obstruction; radioactive iodine; sialadenitis; thyroid cancer; whole-body scintigraphy.

MeSH terms

  • Humans
  • Iodine Radioisotopes / adverse effects
  • Lacrimal Duct Obstruction* / etiology
  • Nasolacrimal Duct*
  • Retrospective Studies
  • Thyroid Neoplasms* / radiotherapy

Substances

  • Iodine-131
  • Iodine Radioisotopes