Radiofrequency ablation (RFA) is a targeted therapy which uses electric energy and heat to destroy the abnormal tissue. RAI is Radioactive Iodine therapy which involves ingesting the radioactive tablet containing the radioactive iodine. This is taken up by all thyroid tissue including the enlarged and hyperfunctioning nodule. The radioactive energy destroys the genetic elements in all thyroid cells and eventually destroys the tissue. Hypothyroidism is a common problem after RAI, but not RFA.