Thyroid scan and iodine
uptake are necessary to differentiate between thyroiditis
(a form of destruction of thyroid with release of preformed hormones into blood) from hyperfunction of thyroid (Graves disease, toxic MNG and adenoma
This is very important as thyroiditis is usually self limiting while the others require prolonged treatment.
There is no other alternative to iodine uptake study. So, kindly get the test done as your doctor prescribed.