Nasolacrimal duct obstruction following radioactive iodine 131 therapy in differentiated thyroid cancers: Review of 19 cases

Abstract

Background: Radioactive iodine 131 ( 131 I) therapy has long been used in the treatment of differentiated thyroid cancers (DTC). While salivary and lacrimal glandular complications secondary to 131 I therapy are well documented, there is little in the literature addressing nasolacrimal duct obstruction (NLDO). We aimed to evaluate the frequency of 131 I therapy-acquired NLDO, its correlation to 131 I therapy doses, and the surgical treatment outcome of this rare side effect. Methods: From 2000–2012, a retrospective review of 864 among 1,192 patients with confirmed DTC who were treated with 131 I therapy was performed to examine the frequency of NLDO, its causative factors, as well as imaging, surgical intervention, and outcomes. Results: Nineteen (2.2%) patients were identified with NLDO. The mean age was 51.9±10.5 years (range: 39–72 years). Fifteen (78.9%) were female and four were male (21.1%). The mean individual 131 I doses were 311.1±169.3 millicurie (mCi) (range: 150–600 mCi). The mean duration between the date of 131 I therapy and the occurrence of NLDO was 11.6±4.1 months (range: 6.5–20). Fourteen (73.7%) patients had bilateral epiphora. Computed tomography dacryography allowed for the detection of all NLDO. Eighteen (94.7%) patients underwent dacryocystorhinostomy. Complete recovery was obtained in 14 (73.7%) patients. Age > 45 years and 131 therapy doses > 150 mCi were significantly correlated with NLDO (P=0.02 and P=0.03, respectively). Conclusion: NLDO is an underestimated complication of 131 therapy in DTC patients. Clinicians should be aware of this rare complication for prompt intervention.