Understanding Radioactive Iodine
Iodine is a naturally occurring element essential for thyroid hormone production, primarily obtained from fortified table salt in the US. Some iodine isotopes are radioactive and used in medical treatments.
Types of Radioactive Iodine
- I-123: Used for diagnostic thyroid scanning
- Half-life of approximately 13 hours
- I-131: Used for thyroid gland ablation in Graves’ disease and thyroid cancer
- Half-life of approximately 5½ days
How Radioactive Iodine Works
- Iodine concentrates exclusively in thyroid tissue
- Hyperthyroid thyroid cells rapidly and completely absorb the iodine
Treatment Applications
Graves’ Disease Treatment
- Used when medications fail or are not tolerated
- Typical dose: 20-50 mCi
- Success rate: Up to 85%
- Second treatment possible if first attempt fails
- Surgery or continued medical therapy considered if treatments are unsuccessful
Treatment Preparation and Process
- No special diet required
- Stop methimazole or PTU 5-10 days before treatment
- Treatment typically done as an outpatient procedure
Side Effects and Aftermath
- Potential side effects:
- Rare nausea (easily controlled)
- Occasional salivary gland discomfort
- All body fluids temporarily radioactive
- Post-treatment management:
- Possible initial symptom intensification
- Resume methimazole and beta blockers for 10 days
- Thyroid levels checked 6-8 weeks after treatment
Long-Term Considerations
- Women of reproductive age should use birth control for 1 year after treatment
Additional Resources
Consult your healthcare provider for personalized medical advice.