For well-differentiated thyroid cancers (papillary and follicular carcinoma), follow-up should include:
• Periodic physical examination, especially of the thyroid and cervical lymph nodes .
• Serologic marker (thyroglobulin). 
• Scanning with radioactive iodine and treatment with 30 MCi (millicuries) (low-risk patients) or 100 MCi
  (high-risk patients if they have had a total or near-total thyroidectomy).
• Periodic ultrasound examinations of the neck to identify recurrence in the thyroid area or lymph node
  metastases.
• Chest x-ray to detect metastases. 
    For medullary thyroid cancer, follow-up should include:
• Serum calcitonin level and CEA level every six months.
• Physical examination, emphasizing the thyroid, although calcitonin level is more accurate than physical
  examination for following persistent disease.
• CT or MRI scan of neck and mediastinum .
• Chest x-ray every six months until stable. 
• Chemistry panel every six months.