From the Research
Radioactive iodine (RAI) treatment is a highly effective therapy for solitary hyperfunctioning thyroid nodules, with a cure rate of 75% within 3 months and a low risk of side effects, making it a preferred treatment option. The typical dose of RAI ranges from 10-30 millicuries (mCi) of I-131, with the specific dose determined based on nodule size, uptake on radioiodine scan, and patient factors 1. Before treatment, patients should undergo thyroid function tests, radioiodine uptake scan, and possibly ultrasound to confirm diagnosis. Antithyroid medications like methimazole (10-30 mg daily) may be used for 1-2 months before RAI to achieve euthyroidism, but should be discontinued 3-7 days prior to treatment.
Some key points to consider when using RAI treatment for solitary hyperfunctioning thyroid nodules include:
- The therapeutic effect develops gradually over 1-3 months as the radioiodine damages the overactive thyroid cells 1
- Success rates exceed 80% with a single treatment, though some patients may require a second dose 1
- Post-treatment monitoring includes thyroid function tests at 6-8 weeks, then every 2-3 months for the first year 1
- Approximately 10-20% of patients develop hypothyroidism requiring lifelong levothyroxine replacement, so long-term follow-up is essential 2
- RAI is contraindicated in pregnancy and breastfeeding, and patients should avoid pregnancy for 4-6 months after treatment
It's also important to note that while RAI treatment is highly effective, it's not without risks. For example, a study found that the cumulative incidence of hypothyroidism was 7.6% at 1 year, 28% at 5 years, 46% at 10 years, and 60% at 20 years 2. However, the benefits of RAI treatment in terms of morbidity, mortality, and quality of life outcomes make it a preferred treatment option for solitary hyperfunctioning thyroid nodules.
In comparison to other treatment options, such as surgery, RAI treatment has been shown to be effective with a low risk of side effects 1. Additionally, a study found that radiofrequency ablation (RFA) may be a good alternative to RAI, with a low risk of permanent hypothyroidism 3. However, the most recent and highest quality study available suggests that RAI treatment is a highly effective and safe treatment option for solitary hyperfunctioning thyroid nodules 1.