Abstract
Purpose: :
To report two cases of nasolacrimal drainage system obstruction associated with I131 therapy for thyroid carcinoma.
Methods: :
Two patients with history of epithelial thyroid carcinoma who complained of epiphora were referred for ophthalmological exam. Case one, 23 y/o white female with follicular thyroid cancer who received two doses of 100 mCi of I131. Case two, 24 y/o white female with papilar thyroid carcinoma who received a dose of 150 mCi and two more doses of 5 mCi of I 131 . Symptoms and signs of lacrimal drainage system obstruction were epiphora, mucous discharge, recurring conjunctivitis, dacryocystitis and mass below the medial canthal tendon. They were referred between six and ten months after radiotherapy.
Results: :
In both patients probing and irrigation revealed complete obstruction of the right nasolacrimal duct in case one, and in both nasolacrimal ducts in case two. This was confirmed by dacryocystography in both cases. The first patient underwent a right dacryocystorhinostomy and biopsy of the lacrimal sac. Histopathologic examination of the lacrimal sac and nasal mucosa revealed fibrosis without malignant cells. We could not perform histopathologic examination of case two because the patient has not been operated yet.
Conclusions: :
We report two cases of lacrimal drainage system obstruction after I131. The lowest cumulative dose of I131 associated with obstruction previously reported was 100 mCi. Symptoms of epiphora developed between six and ten months after I131 therapy. We consider irradiation with I131 was the cause of the obstruction. Patients receiving cumulative doses of at least 100 mCi should be informed of this unusual complication, and physicians should be aware of its presentation to facilitate early diagnosis and treatment.
Keywords: oncology • radiation therapy • lacrimal gland