IoN- Is Ablative Radio-iodine Necessary for Low Risk Differentiated Thyroid Cancer Patients

Inclusion Criteria:

• R0 total thyroidectomy (in one or two stages, no residual disease present) within the last 6 months
• Negative pregnancy test in women of child bearing potential
• Aged 16 or over
• WHO performance status 0 - 2, self-caring
• Histological confirmation of differentiated thyroid carcinoma:

• Papillary thyroid cancer

  • Non aggressive histological features (small foci of aggressive histology allowed)
  • pT1b (1-2cm), intrathyroidal
  • pT2 (2-4cm), intrathyroidal
  • pT3, intrathyroidal only
  • Multifocal microcarcinoma
  • pN0
  • pN1a
  • pNX

• Follicular thyroid cancer/ Hürthle cell cancer (minimally invasive with capsular invasion only)

  • pT1b (1- 2cm), pT2 (2-4cm) intrathyroidal

Exclusion Criteria:

• Papillary and Follicular carcinoma which is unifocal and <1cm in size

• Encapsulated Follicular Variant of Papillary Thyroid Cancer (EFVPTC) that is:

  • non-invasive
  • angio invasive
• Anaplastic or medullary carcinoma
• R1 Thyroidectomy

• Patients with:

  • pN1b
  • M1

• Aggressive Papillary thyroid cancer with the following features:

  • Angio invasive
  • Widely invasive
  • Poorly differentiated
  • Anaplastic differentiation
  • Tall cell
  • Columnar cell
  • Diffuse sclerosing variants

• Follicular thyroid cancer/ Hürthle cell cancer with the following features:

  • Angio invasive
  • Widely invasive
  • Poorly differentiated
  • Tumours greater than 4cm
• Incomplete resection/ lobectomy
• Macroscopic and microscopic tumour invasion of locoregional tissues or structures
• Pregnant women or women who are lactating
• Patients who have CT performed with iv contrast less than 3 months before ablation
• Previous treatment for thyroid cancer (except surgery)
• Previous malignancies with limited life expectancy or likely to interfere with the patient's ability to be able to comply with treatment and/or follow-up at least for 5 years
• Dysphagia
• Oesophageal stricture
• Active gastritis
• Gastric erosions
• Peptic ulcer
• Suspected reduced gastrointestinal motility

• Severe co-morbid condition/s that would prevent ablation including:

  • Unstable angina
  • Recent myocardial infarction or cerebrovascular accident (CVA)
  • Severe labile hypertension

  • Any patient who cannot comply with radiation protection including:

    • patients with learning difficulties
    • patients with dementia
    • patients with a tracheostomy that require nursing care
    • patients requiring frequent nursing/ medical supervision