title: Autonomous functioning thyroid nodules and 131I in diagnosis and therapy after 50 years of experience: what is still open to debate?
abstract: OBJECTIVE
  Autonomous functioning thyroid nodules (AFTN), defined as "hot nodules" at thyroid scan, are often cured by radioiodine treatment. The aim of our study was to investigate the long-term outcome in patients treated with an 131I calculated dose, to identify a possible "size-tailored" dose, and to simplify follow-up procedures.
  
  
  METHODS
  Retrospective analysis was carried out on 1402 cases, covering a period of 50 years, of AFTN treated with an 131I calculated dose. Our study focused on nodular size and mean administered dose. Concordance between thyroid scan and serum TSH levels at 3-6 months from treatment was considered.
  
  
  RESULTS
  A single 131I dose was effective for the vast majority of patients (93%). The outcome was influenced by nodular size. On the basis of the Italian dose limit for outpatient treatment, our population was divided into subgroups according to administered doses (more or less than 16 mCi) and nodular dimensions: no differences in outcome were observed for each class of nodule size. A dose ≤10 mCi was effective on the smaller nodules (50.1% of our population). The agreement between TSH and scan after treatment was 90.3% at 3 months and 94.5% at 6 months.
  
  
  CONCLUSIONS
  131I therapy with a calculated dose is an effective treatment of AFTN. If a fixed dose is chosen, 16 mCi is often resolutive and for nodules <3 cm a dose of 10 mCi can suffice. Nodules >5 cm are eligible for surgery. TSH is the only parameter required to evaluate the outcome.
authors.affiliation: Dipartimento di Medicina Interna e Specialità Mediche, Unità di Medicina Nucleare, Sapienza Università di Roma, Rome, Italy. giuseppe.ronga@uniroma1.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ronga
authors.forename: Mauro
authors.initials: M
authors.lastname: Filesi
authors.forename: Rosaria
authors.initials: R
authors.lastname: D'Apollo
authors.forename: Maria
authors.initials: M
authors.lastname: Toteda
authors.forename: Angelo Domenico
authors.initials: AD
authors.lastname: Di Nicola
authors.forename: Marzia
authors.initials: M
authors.lastname: Colandrea
authors.forename: Laura
authors.initials: L
authors.lastname: Travascio
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Vestri
authors.forename: Teresa
authors.initials: T
authors.lastname: Montesano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008875:Middle Aged; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes