Skip to main content


Log in

Is radioiodine ablation with 1.1 GBq (30 mCi) 131I necessary in low-risk thyroid cancer patients? Results from a long-term follow-up prospective study

  • Original Article
  • Published:
Endocrine Aims and scope Submit manuscript



In patients with low-risk differentiated thyroid cancer (DTC), remnant ablation with radioiodine (RA) after total thyroidectomy (TT) is controversial. No benefits have been demonstrated in terms of mortality or disease-free survival. Recent evidence found that RA did not improve mid-term outcomes.


To evaluate initial response to treatment and long-term follow-up status in low-risk DTC patients after TT vs. TT + RA with 131I 1.11 GBq (30 mCi).


Prospective multicenter non-randomized study; 174 low-risk DTC that underwent TT were recruited an divided in two groups according to RA (87 ablated and 87 non-ablated). Response to treatment was evaluated at 6–18 months after thyroidectomy and at the end of follow-up with measurements of thyroglobulin, and anti-thyroglobulin antibodies levels, and neck ultrasonography.


Baseline characteristics of both groups were similar. Ablated patients: median age 45.5 years, 84% females, 95.4% papillary thyroid carcinoma (PTC), mean tumor size 16 mm; non-ablated: median age 45 years, 88.5% females, 96.6% PTC, mean tumor size 14 mm. Response to initial treatment was similar between both groups, with < 2% of structural incomplete response. Final status was evaluated in 139 cases (median follow-up of 60 months). Among ablated patients, 82.8% had no evidence of disease (NED), 12% had an indeterminate response (IR) and 5% a biochemical incomplete response (BIR). Non-ablated patients had NED in 90%, IR in 8.7% and BIR in 1.2%. No statistical difference was found between groups (p = 0.29). No patient had evidence of structural disease at the end of follow-up.


Our findings support the recommendation against routine RA in low-risk DTC patients.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others


  1. B.R. Haugen, E.K. Alexander, K.C. Bible et al. 2015 American thyroid association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: The American thyroid association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid 26(1), 1–133 (2016)

    Article  PubMed  PubMed Central  Google Scholar 

  2. G.K. Markantes, M. Karakioulaki, S. Papanikolopoulou et al. Improving the prediction of persistent and recurrent differentiated thyroid cancer using the American Thyroid Association 2015 risk stratification system. Hormones 20, 761–768 (2021)

    Article  PubMed  Google Scholar 

  3. F. Pitoia, I. Califano, A. Vázquez et al. Consenso intersocietario sobre tratamiento y seguimiento de pacientes con cáncer diferenciado de tiroides. Rev. Arg. Endocrinol. Metab. 51(2), 85–118 (2014)

    Google Scholar 

  4. R.M. Tuttle, H. Tala, J. Shah et al. Estimating risk of recurrence in differentiated thyroid cancer after total thyroidectomy and radioiodine remnant ablation: using response to therapy variables to modify the initial risk estimates predicted by the new American Thyroid Association guidelines. Thyroid 20(12), 1341–1349 (2010)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. F. Vaisman, H. Tala, R. Grewal, R.M. Tuttle, In differentiated thyroid cancer, an incomplete structural response to therapy is associated with significantly worse clinical outcomes than only an incomplete thyroglobulin response. Thyroid 21(12), 1317–1322 (2011)

    Article  CAS  PubMed  Google Scholar 

  6. F. Vaisman, D. Momesso, D.A. Bulzico et al. Spontaneous remission in thyroid cancer patients after biochemical incomplete response to initial therapy. Clin. Endocrinol. (Oxf.) 77(1), 132–138 (2012)

    Article  CAS  PubMed  Google Scholar 

  7. F. Pitoia, F. Bueno, C. Urciuoli et al. Outcomes of patients with differentiated thyroid cancer risk stratified according to the American Thyroid Association and Latin American Thyroid Society risk of recurrence classification systems. Thyroid 23(11), 1401–1407 (2013)

    Article  PubMed  Google Scholar 

  8. F. Pitoia, F. Jerkovich, C. Urciuoli et al. Implementing the modified 2009 American Thyroid Association risk stratification system in thyroid cancer patients with low and intermediate risk of recurrence. Thyroid 25(11), 1235–1242 (2015)

    Article  PubMed  Google Scholar 

  9. U. Mallick, C. Harmer, B. Yap et al. Ablation with low –dose radioiodine and thyrotrophin alpha in thyroid cancer. N. Engl. J. Med. 366, 1674–1685 (2012).

    Article  CAS  PubMed  Google Scholar 

  10. M. Schlumberger, B. Catargi, I. Borget et al. Strategies of radioiodine ablation in patients with low-risk thyroid cancer. N. Engl. J. Med. 366, 1663–1673 (2012).

    Article  CAS  PubMed  Google Scholar 

  11. L. Lamartina, C. Durante, S. Filetti, D.S. Cooper, Low-risk differentiated thyroid cancer and radioiodine remnant ablation: a systematic review of the literature. J. Clin. Endocrinol. Metab. 100(5), 1748–1761 (2015)

    Article  CAS  PubMed  Google Scholar 

  12. S. Leboulleux, C. Bournaud, C.N. Chougnet et al. Thyroidectomy without radioiodine in patients with low-risk thyroid cancer. N. Engl. J. Med 386, 923–932 (2022)

    Article  CAS  PubMed  Google Scholar 

  13. S.K.A. Súss, C.O. Mesa, G.Ade Carvalho et al. Clinical outcomes of low and intermediate risk differentiated thyroid cancer patients treated with 30mCi for ablation or without radioactive iodine therapy. Arch. Endocrinol. Metab. 62(2), 149–156 (2018)

    PubMed  PubMed Central  Google Scholar 

  14. P.W. Rosario, A.F. Mineiro Filho, B.S. Prates et al. Postoperative stimulated thyroglobulin of less than 1 ng/ml as a criterion to spare low risk patients with papillary. Thyroid cancer Radioact. iodine ablation. Thyroid 22, 1140–1143 (2012)

    CAS  Google Scholar 

  15. P.W. Rosario, G. Mourao, Is 131I ablation necessary for patients with low-risk papillary thyroid carcinoma and slightly elevated stimulated thyroglobulin after thyroidectomy? Arch. Endocrinol. Metab. 60(1), 5–8 (2016)

    Google Scholar 

  16. D.P. Momesso, R.M. Tuttle, Update on differentiated thyroid cancer staging. Endocrinol. Metab. Clin. North. Am. 43, 401–421 (2014)

    Article  PubMed  Google Scholar 

  17. E. Abelleira, F. Bueno, A. Smulever, F. Pitoia, Riesgo dinámico en pacientes con cáncer diferenciado de tiroides no ablacionados. Rev. Arg. Endocrinol. Metab. 54, 69–75 (2017)

    Google Scholar 

  18. I.D. Hay, G.B. Thompson, C.S. Grant et al. Papillary thyroid carcinoma managed at the Mayo Clinic during six decades (1940-1999): temporal trends in initial therapy and long-term outcome in 2444 consecutively treated patients. World J. Surg. 26(8), 879–885 (2002)

    Article  PubMed  Google Scholar 

  19. J. Jonklaas, D.S. Cooper, K.B. Ain et al. National Thyroid Cancer Treatment Cooperative Study Group. Radioiodine therapy in patients with stage I differentiated thyroid cancer. Thyroid 20(12), 1423–1424 (2010)

    Article  PubMed  Google Scholar 

  20. S.E. Mayson, C.M. Chan, B.R. Haugen, Tailoring the approach to radioactive iodine treatment in thyroid cancer. Endocr. Relat. Cancer 28(10), T125–T140 (2021)

    Article  CAS  PubMed  Google Scholar 

  21. P. Goffredo, S.M. Thomas, M.A. Dinan et al. Patterns of use and cost for inappropriate radioactive iodine treatment for thyroid cancer in the United States: use and misuse. JAMA. Intern. Med. 175(4), 638–640 (2015)

    Google Scholar 

  22. R.M. Tuttle, S. Ahuja, A.M. Avram et al. Controversies, Consensus, and Collaboration in the Use of 131I Therapy in Differentiated Thyroid Cancer: A Joint Statement from the American Thyroid Association, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association. Thyroid 29(4), 461–470 (2019)

    Article  PubMed  Google Scholar 

  23. S.A. Gulec, S. Ahuja, A.M. Avram et al. A Joint Statement from the American Thyroid Association, the European Association of Nuclear Medicine, the European Thyroid Association, the Society of Nuclear Medicine and Molecular Imaging on Current Diagnostic and Theranostic Approaches in the Management of Thyroid Cancer. Thyroid 31(7), 1009–1019 (2021)

    Article  PubMed  Google Scholar 

  24. F. Forrer, G.F. Fischer, O. Maas et al. Variations in Radioiodine Therapy in Europe: Decision-Making after Total Thyroidectomy. Oncology 100(2), 74–81 (2022).

    Article  CAS  PubMed  Google Scholar 

  25. F. Pacini, D. Fuhrer, R. Elisei et al. 2022 ETA Consensus Statement: What are the indications for post surgical radioiodine therapy in differentiated thyroid cancer? Eur. Thyroid. J. 11(1), e210046 (2022)

    Article  PubMed  Google Scholar 

  26. U. Mallick, C. Harmer, A. Hackshaw, L. Moss; IoN Trial Management Group. Iodine or Not (IoN) for low-risk differentiated thyroid cancer: the next UK National Cancer Research Network randomised trial following HiLo. Clin Oncol (R Coll Radiol). 24(3), 159–161 (2012)

  27. R. Ciappuccini, J. Hardouin, N. Heutte et al. Stimulated thyroglobulin level at ablation in differentiated thyroid cancer: the impact of treatment preparation modalities and tumor burden. Eur. J. Endocrinol. 171(2), 247–252 (2014)

    Article  CAS  PubMed  Google Scholar 

  28. M. Melo, G. Costa, C. Ribeiro et al. Stimulated thyroglobulin at recombinant human TSH-aided ablation predicts disease-free status one year later. J. Clin. Endocrinol. Metab. 98(11), 4364–4372 (2013)

    Article  CAS  PubMed  Google Scholar 

  29. P.W. Rosario, T.L. Siman, M.R. Calsolari, Day 3 thyroglobulin ≤1 ng/ml after recombinant human TSH just prior to radioactive iodine is predictive of low risk for persistent/recurrent disease in patients with papillary thyroid carcinoma. Endocrine 49(1), 170–174 (2015)

    Article  CAS  PubMed  Google Scholar 

  30. F. Pitoia, E. Abelleira, G. Cross, Thyroglobulin levels measured at the time of remnant ablation to predict response to treatment in differentiated thyroid cancer after thyroid hormone withdrawal or recombinant human TSH. Endocrine 55(1), 200–208 (2017)

    Article  CAS  PubMed  Google Scholar 

  31. S. Park, W.G. Kim, E. Song et al. Dynamic risk stratification for predicting recurrence in patients with differentiated thyroid cancer treated without radioactive iodine remnant ablation therapy. Thyroid 27(4), 524–530 (2017)

    Article  CAS  PubMed  Google Scholar 

  32. F. Pitoia, E. Abelleira, H. Tala et al. Biochemical persistence in thyroid cancer: is there anything to worry about. Endocrine 46(3), 532–537 (2014)

    Article  PubMed  Google Scholar 

  33. L. Lamartina, S. Leboulleux, M. Terroir et al. An update on the management of low-risk differentiated thyroid cancer. Endocr.-Relat. Cancer 26, R597–R610 (2019)

    Article  CAS  PubMed  Google Scholar 

  34. R. Chou, T. Dana, G.A. Brent et al. Serum Thyroglobulin measurement following surgery without radioactive iodine for differentiated thyroid Cancer: A Systematic Review. Thyroid 32(6), 613–639 (2022)

    Article  CAS  PubMed  Google Scholar 

Download references


We thank the members of the Thyroid Department of Sociedad Argentina de Endocrinología y Metabolismo:

Abalovich Marcos, Abelleira Erika, Alcaraz Graciela, Bielsky Laila, Brenta Gabriela, Cabezón Carmen, Calabrese M. Cristina, Castro Jozami Lorena, Delfino Laura, Deutsch Susana, Fassi Julieta, Frascaroli Genoveva, Gauna Alicia, Guerra Jorgelina, Jerkovich Fernando, Lowenstein Alicia, Martínez María Paz, Moldes Sofía, Negueruela M. del Carmen, Oneto Adriana, Orlandi Ana María, Parisi Carina, Reyes Adriana, Rosemblit Cynthia, Russo Picasso Fabiana, Saban Melina, Sala Mónica, Schiro Laura, Schnitman Marta, Sklate Rosana, Silva Croome M. del Carmen, Storani María Elena, Zund Santiago, Zunino Anabela.

Author information

Authors and Affiliations




All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by VI, IC, and AC. The first draft of the paper was written by VI, IC, and AC and all authors commented on previous versions of the paper. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Fabián Pitoia.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Ethics approval

This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of each hospital.

Consent to participate

Informed consent was obtained from participants included in the study.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ilera, V., Califano, I., Cavallo, A. et al. Is radioiodine ablation with 1.1 GBq (30 mCi) 131I necessary in low-risk thyroid cancer patients? Results from a long-term follow-up prospective study. Endocrine 80, 606–611 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: