Treatment Efficacy and Safety of Low-dose Radioiodine Ablation for Intermediate-risk Differentiated Thyroid Carcinoma

Primary objective: The 3-years disease-free survival was compared between low-dose group (30 mCi) and high-dose group (100 mCi). Secondary objective: The successful remnant ablation, efficacy, 3-year progression-free survival and safety were compared between low-dose group (30 mCi) and high-dose group (100 mCi). Research Hypothesis：The 3-year disease-free survival of low-dose group (30mci) may not be lower than that of high-dose group (100 mci) in intermediate-risk thyroid papillary carcinoma patients with no structural or functional lesions and stimulated thyroglobulin(ps-Tg)1-20ng/ml. Study design：Single-center, randomized, double-blinded Sample size：254 patients Follow-up：The measurement of serum thyroid function, thyroglobulin/ anti-thyroglobulin antibody(Tg/TgAb) and neck ultrasonography were performed every 3-12 months during the 3 years according to patients' condition, and computerized tomography(CT) scan, positron emission tomography/computed tomography(PET/CT) and diagnostic whole-body 131I scan were added if necessary. Intervention：Randomly allocated into two groups to receive either 30 mCi (low-dose group) or 100 mCi (high-dose group ) radioiodine for post-thyroidectomy ablation therapy. Evaluation index：Primary evaluation index: The 3-year disease-free survival. Secondary evaluation index: Successful remnant ablation, efficacy, the 3-year progression-free survival and safety.

Sex

All

Minimum age

16 Years

Inclusion Criteria:

* Patients with histological confirmation of intermediate-risk papillary thyroid carcinoma(PTC) according to 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer.
* Differentiated Thyroid Carcinoma(DTC) patients who underwent total or near-total thyroidectomy which was consistent with the recommendations of American Thyroid Association guidelines as well as Chinese Thyroid Association guidelines on the management of Differentiated Thyroid Carcinoma(DTC).
* Serum stimulated thyroglobulin was 1-20ng/ml.
* At least 16 years old.
* Patients who volunteered to participate in the study and signed informed consent.

Exclusion Criteria:

* Ultrasonography, Computerized Tomography(CT), Magnetic Resonance Imaging(MRI) or Positron Emission Tomography/computed tomography (PET/CT) indicates the presence of lesions.
* Iodine-131 whole body scan indicates the presence of lesions outside the thyroid bed.
* Patients with positive thyroglobulin antibody (≥115 Ku/L).
* Patients who had other coexisting serious diseases or other factors that may affect the outcome of ablation.
* Pregnant or breastfeeding women, or with birth planning within six months.

• BACKGROUNDHaugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, Pacini F, Randolph GW, Sawka AM, Schlumberger M, Schuff KG, Sherman SI, Sosa JA, Steward DL, Tuttle RM, Wartofsky L. 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. 2016 Jan;26(1):1-133. doi: 10.1089/thy.2015.0020. PMID 26462967
• BACKGROUNDSchlumberger M, Catargi B, Borget I, Deandreis D, Zerdoud S, Bridji B, Bardet S, Leenhardt L, Bastie D, Schvartz C, Vera P, Morel O, Benisvy D, Bournaud C, Bonichon F, Dejax C, Toubert ME, Leboulleux S, Ricard M, Benhamou E; Tumeurs de la Thyroide Refractaires Network for the Essai Stimulation Ablation Equivalence Trial. Strategies of radioiodine ablation in patients with low-risk thyroid cancer. N Engl J Med. 2012 May 3;366(18):1663-73. doi: 10.1056/NEJMoa1108586. PMID 22551127
• BACKGROUNDMallick U, Harmer C, Yap B, Wadsley J, Clarke S, Moss L, Nicol A, Clark PM, Farnell K, McCready R, Smellie J, Franklyn JA, John R, Nutting CM, Newbold K, Lemon C, Gerrard G, Abdel-Hamid A, Hardman J, Macias E, Roques T, Whitaker S, Vijayan R, Alvarez P, Beare S, Forsyth S, Kadalayil L, Hackshaw A. Ablation with low-dose radioiodine and thyrotropin alfa in thyroid cancer. N Engl J Med. 2012 May 3;366(18):1674-85. doi: 10.1056/NEJMoa1109589. PMID 22551128
• BACKGROUNDDehbi HM, Mallick U, Wadsley J, Newbold K, Harmer C, Hackshaw A. Recurrence after low-dose radioiodine ablation and recombinant human thyroid-stimulating hormone for differentiated thyroid cancer (HiLo): long-term results of an open-label, non-inferiority randomised controlled trial. Lancet Diabetes Endocrinol. 2019 Jan;7(1):44-51. doi: 10.1016/S2213-8587(18)30306-1. Epub 2018 Nov 27. PMID 30501974