<prompt> Treatment of Medullary carcinoma of thyroid isSurgery and RadiotherapyRadiotherapy and ChemotherapySurgery onlyRadioactive ablation  <response>: Management Total thyroidectomy Routine central lymph node dissection ipsilateral modified radical node dissection Tumor 1cm - Bilateral modified Radical neck dissection if any lymph node is positive MCT - Poor prognosis because it does not respond to radioactive iodine ablation Vandetanib - Only FDA approved drug in advanced progressive medullary thyroid cancer. 