Hello – Yes, RAI will generally destroy the thyroid gland as well as any “hot” nodules. (Nodules that are actively pouring out thyroid hormone).
However, a certain percentage of patients end up needing to repeat the treatment. An article from the New England Journal of Medicine from a couple of years ago noted that the RAI “failure” rate is 10-30% for patients with a single nodule. That same article also notes a 14% “failure” rate for patients who have hyperthyroidism, but NOT nodules.
Are your levels back in (or approaching) the “normal” range? If so, hopefully, you won’t need a second treatment. Please keep us posted on how you are doing!