A comparison of 1850 (50 mCi) and 3700 MBq (100 mCi) 131-iodine administered doses for recombinant thyrotropin-stimulated postoperative thyroid remnant ablation in differentiated thyroid cancer

J Clin Endocrinol Metab. 2007 Sep;92(9):3542-6. doi: 10.1210/jc.2007-0225. Epub 2007 Jul 3.


Objective: Recently, a multicenter study in differentiated thyroid cancer (DTC) patients showed that 3700 MBq 131-iodine ((131)I) after recombinant human TSH (rhTSH) had a successful thyroid ablation rate similar to that obtained after thyroid hormone withdrawal. We investigated whether 1850 MBq (131)I had a similar successful rate to 3700 MBq in patients prepared with rhTSH.

Design: A total of 72 patients with DTC were randomly assigned to receive 1850 (group A, n = 36) or 3700 MBq (group B, n = 36) (131)I after rhTSH. One injection of 0.9 mg rhTSH was administered for 2 consecutive days; (131)I therapy was delivered 24 h after the last injection, followed by a posttherapy whole-body scan. Successful ablation was assessed 6-8 months later.

Results: Successful ablation (no visible uptake in the diagnostic whole-body scan after rhTSH stimulation) was achieved in 88.9% of group A and B patients. Basal and rhTSH-stimulated serum thyroglobulin was undetectable (<1 ng/ml) in 78.9% of group A and 66.6% of group B patients (P = 0.46). Similar rates of ablation were obtained in both groups also in patients with node metastases.

Conclusion: Therapeutic (131)I activities of 1850 MBq are equally effective as 3700 MBq for thyroid ablation in DTC patients prepared with rhTSH, even in the presence of node metastases.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Carcinoma / drug therapy*
  • Carcinoma / pathology
  • Carcinoma / radiotherapy*
  • Carcinoma / surgery*
  • Chemotherapy, Adjuvant
  • Disease Progression
  • Female
  • Humans
  • Iodine Radioisotopes / administration & dosage*
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • Neoplasm, Residual
  • Radiometry
  • Radiotherapy Dosage
  • Recombinant Proteins / therapeutic use
  • Salvage Therapy
  • Thyroid Neoplasms / drug therapy*
  • Thyroid Neoplasms / pathology
  • Thyroid Neoplasms / radiotherapy*
  • Thyroid Neoplasms / surgery*
  • Thyrotropin / therapeutic use*


  • Iodine Radioisotopes
  • Recombinant Proteins
  • Thyrotropin