Chance of having a second dose of radio iodine treatment?

It really depends on if you had the correct dose and how much lingering thyroid tissue you had left. Radioiodine ablation will not do a good job in killing large amounts of tissue as well as lymph nodes. If you just had microscopic tissue left, there's a good chance that once dose will work...but it's not uncommon to need two or more doses. Good luck!