While I am unable to make a spcific comment about your individual case, studies show that while a majority of people require only a single radioactive iodine treatment for an overactive thyroid gland, some (less than 5%) may require a repeat treatment to control this condition.
With repeat treatment the chances of later onset hypothryoid become higher..., but other than this there are no major problems with this drug. In fact, the incidence of thyroid cancer is less in such treated glands, probably because of the destruction of the thyroid tissue.
Radioactive iodine is a safe, effective, and time tested (over 50 years of use) treatment of hyperthyroidism.
While isolation is NOT needed, for approximately 11 days after treatment prolonged (more than 2 hours in 24 hours) contact with pregnant/ breastfeeding mothers and children should be avoided..
For more precautions read here
all the best
Dr. Gupta

