Differentiated Thyroid Cancer: is There a Need for Radioiodine Ablation in Low Risk Patients?
Differentiated Thyroid Cancer: is There a Need for Radioiodine Ablation in Low Risk Patients?
Open-label randomized phase III trial, using a non-inferiority comparison design. After
 randomization,patients will receive either post-operative radioiodine ablation with an
 activity of 1.1 GBq (30 mCi) after stimulation by rhTSH, and then be followed-up (ablation
 group) or be followed-up (without postoperative radioiodine ablation) (follow-up group).

 The objective is to assess the non-inferiority of the proportion of patients without
 tumor-related event evaluated at three years after randomisation in the absence of
 radioiodine ablation (follow-up group) compared to the ablation group, in patients with
 low-risk differentiated thyroid cancer treated with total thyroidectomy with or without lymph
 node dissection (pT1am N0 or Nx, pT1b N0 or Nx)
Inclusion Criteria:

 1. Patients with differentiated thyroid cancer (papillary, follicular or with Hurthle
 cells) in the absence of aggressive histological subtypes (poorly differentiated,
 tall-clear-cylindric cell, diffuse sclerosing or with an anaplastic component)

 2. Patients having undergone a total thyroidectomy with complete (R0) tumor resection,
 with or without lymph node neck dissection

 3. Total thyroidectomy performed 2 to 5 months before inclusion

 4. Patients with low risk of recurrence: pT1amN0 or pT1amNx with a sum of the size of the
 lesions above 1 cm and equal to or less than 2 cm, or pT1bN0 or pT1bNx (TNM 2010
 classification). (Patients with less than 6 lymph nodes in the neck dissection will be
 classified as Nx)

 5. Post-operative neck ultrasound (performed 2 to 5 months after surgery) showing the
 absence of abnormalities in the lateral lymph node compartments, or if abnormalities,
 no lymph nodes with abnormal cytology and/or thyroglobulin concentration in the
 aspirate fluid > 10 ng/mL

 6. Age >=18 years

 7. Performance status of 0 or 1

 8. Patients who signed the informed consent

 9. Patients who can be followed-up annually during 5 years in order to assess the
 objectives of the study

 10. Women of childbearing age should have a negative pregnancy test before any radioiodine
 administration

 11. Both patients with or without thyroglobulin antibodies are eligible

 Exclusion Criteria:

 1. Patients having undergone less than a total thyroidectomy

 2. Patients with aggressive histotype (poorly differentiated, tall-clear-cylindric cell,
 diffuse sclerosing, or with an anaplastic component)

 3. Patients having undergone surgery less than 2 months or more than 4 months before
 inclusion

 4. Patients with cancer classified as pT1a unifocal (in which ablation is not necessary),
 or pT1N1, pT2, pT3, pT4 or N1 (who have a higher risk of recurrence) (classification
 TNM 2010)

 5. Patient with known distant metastasis

 6. Abnormal post-operative neck ultrasound of the lateral lymph node compartments

 7. Patients with another malignancy not in remission for at least 2 years (except for in
 situ cervix uterine cancer, basocellular skin cancer)

 8. Patients with a recent history of drugs affecting thyroid function, including
 injection of radiocontrast agents during the last 8 weeks.

 9. Patients previously treated with radioactive iodine or who previously underwent a
 whole body scan with radioactive iodine

 10. Pregnant or breast feeding women

 11. Subject with any kind of disorder that may compromise his/her ability to give written
 informed consent and/or to comply with study procedures