RAI is usually not done unless one has Graves Disease; it's also done following surgery if cancer is involved.
Many of us have multi nodular goiter and nothing needs to be done. Quite often when one has a goiter, they also have antibodies which attack and destroy the thyroid gland. These antibodies could be from either Graves Disease or Hashimoto's thyroiditis and both eventually end up causing the thyroid to stop making enough hormones, leaving the patient dependent on replacement med.
Do you have any recent thyroid blood work results that you could post? Those would be TSH, Free T3 and Free T4, and possibly antibody tests. If so, please post results, along with reference ranges, since these vary from lab to lab and must come from your own report.
Once you have Hashimoto's, you have it for life.
It depends if the goitre is becoming a problem. Many people have multi-nodular goitres and do just fine. Some need thyroid replacement medication to shrink it down a bit.
RAI isn't the usual treatment unless Grave's disease is involved, where the nodules are leaking extra thyroid hormone.