title: [Lacrimal drainage system obstruction associated to radioactive iodine therapy for thyroid carcinoma].
abstract: OBJECTIVE
  To report the finding of nasolacrimal drainage system obstruction associated with radio iodine therapy and to review clinical data and the surgical treatment outcome of this rare complication.
  
  
  METHODS
  We retrospectively analyzed ophthalmological data of patients with history of thyroid carcinoma that underwent radioactive iodine I-131 therapy and were referred to lacrimal surgery.
  
  
  RESULTS
  17 patients with thyroid cancer treated with thyroidectomy and radioactive iodine I-131 therapy presented symptomatic nasolacrimal duct obstruction after 13.2 months following cancer treatment. 11 patients presented bilateral epiphora, 8 had lacrimal sac mucocele. Age range was 30 to 80 years, 10 patients had less than or equal to 49 years. The mean cumulative dose of radioiodine was 571 mCi (range: 200-1200 mCi). Nasal obstruction symptoms and increased salivary glands were also present in 53% of patients. All subjects underwent dacryocystorhinostomy. Dilation of the lacrimal sac and increased intraoperative bleeding was also observed in 3 younger patients. Complete epiphora and dacryocystitis resolution after surgery occurred in 82.4%, and partial in 17.6% (3 patients that still presented unilateral relapse after correction of bilateral obstruction). Mean follow-up was 6 months (range: 2-24 months).
  
  
  CONCLUSIONS
  Cumulative high dose of radioiodine, nasal and salivary gland dysfunction are associated with lacrimal drainage obstruction. We observed a great percentage of younger patients presenting dacryocystitis when compared to the idiopathic dacryostenosis. Radioactive iodine uptake by nasolacrimal duct mucosa with subsequent inflammation, edema and fibrosis seems to have a relationship to lacrimal duct obstruction. The knowledge of this complication is important for the study and proper management of these patients.
authors: Setor de Plástica Ocular, Divisão de Clínica Oftalmológica, Hospital das Clínicas, Faculdade de Medicina,Universidade de São Paulo - USP - São Paulo (SP), Brasil.
authors: Fabricio Lopes da
authors: FL
authors: Fonseca
authors: Patrícia
authors: P
authors: Lunardelli
authors: Suzana
authors: S
authors: Matayoshi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D007767:Lacrimal Duct Obstruction / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000528:radiation effects*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000150:complications; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000532:radiotherapy*
chemical_list: D007457:Iodine Radioisotopes