Why in news?
Hospitals in India continue to rely on radioactive iodine therapy to treat thyroid disorders. Public health magazines in July 2025 highlighted the safety and effectiveness of this treatment, sparking interest in nuclear medicine among readers.
Historical development
Radioactive iodine therapy was pioneered in the 1930s. In 1936 researchers at the Massachusetts General Hospital produced iodine‑131 (I‑131), a radioactive isotope. Two years later they treated a patient with hyperthyroidism by administering I‑131 orally. The isotope accumulates naturally in the thyroid gland, where it emits beta radiation that destroys overactive or cancerous tissue.
How the therapy works
- Targeted delivery: Patients swallow a capsule or liquid containing I‑131. Because the thyroid absorbs iodine from the blood, most of the radioactivity goes directly to the gland.
- Destruction of diseased cells: The beta particles emitted by I‑131 damage DNA inside thyroid cells, causing them to shrink or die. This reduces hormone production in cases of hyperthyroidism and eliminates remaining cancer cells after surgery.
- Out‑patient procedure: Treatment is simple and non‑surgical. Patients usually return home the same day but must follow radiation safety precautions for a few days, such as limiting close contact.
- Follow‑up: Doctors monitor hormone levels and may prescribe hormone replacement if the thyroid is completely ablated.
Benefits and considerations
Radioactive iodine therapy has transformed the management of hyperthyroidism and thyroid cancer. It is relatively inexpensive compared to surgery, avoids surgical risks and is highly effective. However, pregnant and breastfeeding women cannot undergo the treatment. Patients must be counselled on fertility, and there is a small risk of secondary cancers with very high doses. Overall, when used judiciously under medical supervision, radioactive iodine is a safe and valuable tool in nuclear medicine.