Brief Answer:
Thyroid

Detailed Answer:
I understand what you are saying.

Ablation of cysts/nodules with alcohol is practiced in few centers in USA and indeed worldwide.

Let me clarify a few things first.

In your medical history it says Graves disease. It also mentions allergy to PTU.

Now when the radio-active iodine uptake and scan is performed it typically shows one of the two (and not both) ie either Graves disease or a 'Multi Nodular Goiter' (MNG), although nodules/cysts can be present in a thyroid affected by Graves disease too.

So first one needs to ascertain the cause of the overactive thyroid in your case.

Regarding the likelihood of becoming permanently hypothyroid (and requiring synthroid type medication forever), it is high in both instances if ablation with radio-active iodine is done. However there is no test in the world that can 100% predict the outcome, but the vast majority will not have any functioning thyroid left.

Sometimes even a second or rarely a third radiation treatment becomes necessary but your doctor is correct in stating that a robust dose is given in the first attempt that often is sufficient.

In either Graves or 'toxic' MNG (toxic is the term used to describe a thyroid gland in with multiple nodules are over-active, in contrast with non toxic where it does not produce excessive thyroid hormones and the TSH is normal), treatment with alcohol is unlikely to work. it has been tried in research setting and found to work best when there is only a limited number (typically one) of overactive thyroid nodules.
Another such treatment option is laser.

But these two methods are not used for Graves nor for TMNG as they are not effective.

Plain cysts sometimes resolve after aspiration ie removal of the fluid from them using a fine needle procedure. but sometimes they re-occur

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Brief Answer:
Follow up

Detailed Answer:
You are welcome. Best wishes

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