Abstract
Background: Radioactive iodine 131 (I-131) therapy has long been used in the treatment of differentiated thyroid cancers (DTC). While salivary and lacrimal glandular complications secondary to I-131 therapy are well documented, there is little in the literature addressing nasolacrimal duct obstruction (NLDO). We aimed to evaluate the frequency of I-131 therapy-acquired NLDO, its correlation to I-131 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 I-131 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 I-131 doses were 311.1 +/- 169.3 millicurie (mCi) (range: 150-600 mCi). The mean duration between the date of I-131 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 I-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 I-131 therapy in DTC patients. Clinicians should be aware of this rare complication for prompt intervention.