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

Abstract

Khalid Hussain Al-Qahtani,1 Mushabbab Al Asiri,2 Mutahir A Tunio,2 Naji J Aljohani,3 Yasser Bayoumi,4 Iqbal Munir,5 Ayman AlAyoubi6 1Department of Otolaryngology – Head and Neck Surgery, College of Medicine, Advanced Head and Neck Oncology, King Saud University, 2Radiation Oncology, Comprehensive Cancer Center, King Fahad Medical City, 3Endocrinology and Thyroid Oncology, King Fahad Medical City, Riyadh, Saudi Arabia; 4Radiation Oncology, NCI, Cairo University, Cairo, Egypt; 5Nuclear Medicine Sulaiman Al-Habib Hospital, 6Clinical Ophthalmology, King Fahad Medical City, Riyadh, Saudi Arabia Background: Radioactive iodine 131 (131I) therapy has long been used in the treatment of differentiated thyroid cancers (DTC). While salivary and lacrimal glandular complications secondary to 131I therapy are well documented, there is little in the literature addressing nasolacrimal duct obstruction (NLDO). We aimed to evaluate the frequency of 131I therapy-acquired NLDO, its correlation to 131I 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 131I 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 131I doses were 311.1±169.3 millicurie (mCi) (range: 150–600 mCi). The mean duration between the date of 131I 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 131I therapy doses >150 mCi were significantly correlated with NLDO (P=0.02 and P=0.03, respectively).Conclusion: NLDO is an underestimated complication of 131I therapy in DTC patients. Clinicians should be aware of this rare complication for prompt intervention. Keywords: nasolacrimal duct obstruction, radioactive iodine 131 therapy, differentiated thyroid cancers