**11. Follow-ups**

Long-term follow-up after RAI therapy is needed. The likelihood of eventual hypothyroidism can occur within 2–3 months after therapy or even decades later, with a small, ongoing annual incidence. Lifelong thyroid hormone supplementation would then become necessary and should be started when thyroid-stimulating hormone elevation is detected and should have as its goal a euthyroid, symptomfree state [23]. Transient hypothyroidism is reported in 3–20% of cases. It does not invariably lead to permanent hypothyroidism, but thyroid hormone supplementation is generally recommended.

## **12. Conclusions**

RAI therapy is safe as definitive therapy and cost-effective for Graves' Disease definitive treatment. The treatment has to be individualized. Patients should fully understand the treatment procedures to reach the desired outcome and handle the risks and adverse effects. Three approaches for determining the administered RAI activity doses. 1. Based on the calculation of thyroid volume and the RAI uptake 24 hours. 2. Based on thyroid volume, RAI uptake, effective half-life. 3. Fixed activity dose. However, the effectiveness is an equally successful outcome between them. RAI treatment aims in GD is to control hyperthyroid rather than avoidance of hypothyroidism. Hypothyroidism can occur within the first three months after RAI therapy or even decades later. Lifelong follow-up is needed to ensure recurrence of disease, and hypothyroidism is detected. Thyroid hormone supplementation would then become necessary and should be started when thyroid-stimulating hormone elevation is detected. Long-term studies show that radiation does not induce genetic damage or malignancy. However, conception should be delayed at least for six months after the therapy. So, the physician needs to provide written information for the patients to avoid miss interpretation.
