title: Lingual Thyroid Ectopia: Diagnostic SPECT/CT Imaging and Radioactive Iodine Treatment.
abstract: BACKGROUND
  Lingual thyroid is a rare abnormality of thyroid development that is usually treated conservatively with levothyroxine replacement. Rarely, it becomes large enough to cause obstructive symptoms in the oral cavity, requiring definitive treatment.
  
  
  METHODS
  This study reports on three patients with lingual thyroid treated with radioactive iodine-131 ((131)I) with successful radioablation of their ectopic thyroid tissues. Measurement of 24-hour radioactive iodine uptake within thyroidal tissues and hybrid single-photon emission computed tomography/computed tomography imaging using either iodine-123 or technetium-99m pertechnetate scans were performed in all patients demonstrating the location and size of lingual thyroid and absence of an orthotopic thyroid gland.
  
  
  CONCLUSIONS
  The aim of this study was to describe nonsurgical management of obstructive lingual thyroid tissue with (131)I therapy for lingual thyroid radioablation. Patients were prepared with a low-iodine diet and levothyroxine withdrawal prior to radioablation for optimizing (131)I uptake in ectopic thyroid tissues. Hybrid single-photon emission computed tomography/computed tomography measurement of anatomic size of lingual thyroid tissue and radioactive iodine uptake guided the selection of therapeutic doses, resulting in administration of 10.7, 17.5, and 15.4 mCi of (131)I, respectively. There were no post-therapy complications, and clinical follow-up demonstrated resolution of obstructive oropharyngeal symptoms.
  
  
  CONCLUSIONS
  Ectopic lingual thyroid tissue is rarely associated with obstructive oropharyngeal symptoms due to progressive enlargement. Radioiodine therapy with (131)I is an effective treatment modality for ablation of ectopic thyroid tissue as an alternative to surgery.
authors: 1 Nuclear Medicine/Radiology, University of Michigan , Ann Arbor, Michigan.
authors: Arpit
authors: A
authors: Gandhi
authors: 1 Nuclear Medicine/Radiology, University of Michigan , Ann Arbor, Michigan.|2 Nuclear Medicine Service , Department of Veterans Affairs Health System, Ann Arbor, Michigan.
authors: Ka Kit
authors: KK
authors: Wong
authors: 1 Nuclear Medicine/Radiology, University of Michigan , Ann Arbor, Michigan.|2 Nuclear Medicine Service , Department of Veterans Affairs Health System, Ann Arbor, Michigan.
authors: Milton D
authors: MD
authors: Gross
authors: 1 Nuclear Medicine/Radiology, University of Michigan , Ann Arbor, Michigan.
authors: Anca M
authors: AM
authors: Avram
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000737:chemistry*; D046151:Lingual Thyroid / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy; D008875:Middle Aged; D000072098:Single Photon Emission Computed Tomography Computed Tomography; D013670:Sodium Pertechnetate Tc 99m / Q000737:chemistry; D050033:Thyroid Dysgenesis / Q000000981:diagnostic imaging; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013964:Thyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy; D013974:Thyroxine / Q000009:adverse effects; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D013670:Sodium Pertechnetate Tc 99m; D013974:Thyroxine