An Arky- sorry to hijack, radioiodine is one of three treatment modalities for hyperthyroidism.
The other two are drugs (Propylthiouracil and Carbimazole) and surgery.
The drugs need to be taken long term by the majority of patients and have some very serious possible side effects (bone marrow suppression).
Surgery to thyroid has associated risks of bleeding, infection, anaesthesia and damage to the nerves to the larynx, which can lead to permanant damage to the quality of the voice.
Radioiodine, in contrast is non invasive (one drink or capsule, no surgery, no needles, no side effects) which either renders the patient euthyroid and no further treatment is required, or it causes the patient to become hypothyroid, and synthetic thyroid hormone is prescribed. The synthetic thyroxine is much safer and better tolerated than either of the drugs for hyperthyroidism, as it simply replaces what the body is missing.
While you may feel that radioiodine is invasive and not a good option, the reality is that there are other options, but they’re probably less acceptable to the majority of patients. Radioiodine is very effective, safe (as long as it isn’t done on a woman of child-bearing age) and is considered the definitive treatment of choice.