title: Patients with differentiated thyroid cancer who underwent radioiodine thyroid remnant ablation with low-activity ¹³¹I after either recombinant human TSH or thyroid hormone therapy withdrawal showed the same outcome after a 10-year follow-up.
abstract: BACKGROUND
  No long-term follow-up data are available for differentiated thyroid carcinoma (DTC) patients prepared with either exogenous or endogenous TSH and treated with low-activity (1.1 GBq [30 mCi]) radioiodine (¹³¹I).
  
  
  OBJECTIVE
  The aim of this study was to evaluate the 10-year follow-up of DTC patients who underwent remnant ablation with 1.1 GBq ¹³¹I after l-T4 withdrawal, recombinant human TSH (rhTSH) administration, or both.
  
  
  METHODS
  A total of 159 DTC patients treated with total thyroidectomy and 1.1 GBq (30 mCi) of ¹³¹I for remnant ablation and stimulated with rhTSH and/or endogenous TSH were separated into ablated (n = 115) and not ablated (n = 44) patients and prospectively followed-up for at least 10 years. In addition, we evaluated several features that could correlate with the final status of patients.
  
  
  RESULTS
  During the follow-up, 4 of 115 (3.5%) ablated patients showed a recurrence and 1 was successfully cured. Among not ablated patients, 16 of 44 (36.4%) had a persistent disease. At the end of the 10-year follow-up, 140 of 159 (88.1%) patients were disease-free, whereas 19 of 159 (11.9%) remained affected. No correlation was found with the type of TSH stimulation, and no other clinical and pathological features showed any correlation with the final status. However, low levels of stimulated serum thyroglobulin (<5.4 ng/mL) at first control after remnant ablation identified a subgroup of not ablated patients who became spontaneously cured.
  
  
  CONCLUSIONS
  Long-term outcomes are similar in DTC patients treated with 1.1 GBq (30 mCi) ¹³¹I and prepared either with rhTSH or endogenous TSH. It is of interest that serum thyroglobulin at first control after ablation can have a prognostic role.
authors.affiliation: Unit of Endocrinology, Department of Clinical and Experimental Medicine, World Health Organization Collaborating Center for the Study and Treatment of Thyroid Diseases and Other Endocrine and Metabolic Disorders, University of Pisa, 56100 Pisa, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Molinaro
authors.forename: Carlotta
authors.initials: C
authors.lastname: Giani
authors.forename: Laura
authors.initials: L
authors.lastname: Agate
authors.forename: Agnese
authors.initials: A
authors.lastname: Biagini
authors.forename: Letizia
authors.initials: L
authors.lastname: Pieruzzi
authors.forename: Francesca
authors.initials: F
authors.lastname: Bianchi
authors.forename: Federica
authors.initials: F
authors.lastname: Brozzi
authors.forename: Claudia
authors.initials: C
authors.lastname: Ceccarelli
authors.forename: David
authors.initials: D
authors.lastname: Viola
authors.forename: Paolo
authors.initials: P
authors.lastname: Piaggi
authors.forename: Paolo
authors.initials: P
authors.lastname: Vitti
authors.forename: Furio
authors.initials: F
authors.lastname: Pacini
authors.forename: Rossella
authors.initials: R
authors.lastname: Elisei
mesh_terms: D000328:Adult; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011292:Premedication; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000627:therapeutic use*; D011994:Recombinant Proteins / Q000627:therapeutic use; D012074:Remission Induction; D013954:Thyroglobulin / Q000097:blood; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use*; D013974:Thyroxine / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D011994:Recombinant Proteins; D013972:Thyrotropin; D013954:Thyroglobulin; D013974:Thyroxine