Radioactive Iodine Therapy
Radioactive iodine therapy, colloquially known as “atomic therapy", is postoperatively started in thyroid cancer. It is the only therapeutic option, which aims eliminating cancer cells in residual thyroid tissue, lymph node and other body regions. Radioactive iodine therapy facilitates postoperative follow-up of the patient by eliminating rest tissue in thyroid bed. Moreover, it demonstrates and treats micro-metastases, resulting with reduced risk of recurrence and prolonged survival.
Radioactive Iodine therapy of thyroid cancers
Studies had evidenced that radioactive iodine therapy given to selected patients in postoperative period of correct surgery totally eliminates disease in more than 95% of patients.
Who are eligible for radioactive iodine therapy?
Patients, who will be started on this therapy, are identified in early postoperative period, and radioactive iodine therapy can be started approximately at postoperative Week 3 or 4.
It is reserved for papillary and follicular carcinomas, which are also known as differentiated thyroid cancer. It offers ablative (elimination of rest thyroid tissue which cannot be surgically excised) and therapeutic options for patients with tumor measuring >1 cm in diameter. Total thyroidectomy alone can be sufficient, if diameter of tumor is <1 cm; although diameter of tumor is <1 cm, radioactive iodine therapy is started, if metastasis is found, capsule is invaded, patient has anamnesis of radiotherapy or tumor cell is malignant.
When should preparations of radioactive iodine therapy be started?
The principle is increasing concentration of TSH in order to increase therapeutic efficiency by facilitating influx of iodine-131 to rest thyroid and tumor cells. Generally, this therapy can be started at postoperative Week 3 or 4. Post-therapy planning is made in order to avoid prolonged hypothyroidism and to increase quality of life. Success rate of therapy increases substantially, if patient is maintained on iodine-poor diet for 10 to 15 days before therapy is started. Patient-specific plan is made by Nuclear Medicine specialist and patient should be informed in detail.
How is radioactive iodine therapy applied?
- Patient should be fasting for approximately 6 hours before visiting the hospital in the morning of iodine therapy.
- Blood will be drawn for required analyses and patient is admitted to radioactive therapy room (covered with lead), where patient receives iodine therapy.
- Radioactive substance is given in the form of capsule by mouth.
- Patient stays in this room for 3 to 5 days depending dose of drug.
What are side effects of radioactive iodine therapy and possible precautions?
Radioactive iodine capsule has no bad taste or smell; patient feels nothing during therapy. Contrary to other chemotherapeutic methods, hair loss does not apply to this therapy. Gastrointestinal side effects are very rare in this therapeutic modality. Some recommendations are made to avoid hazardous effects of therapy on salivary gland. Moreover, abundant oral hydration and daily shower ensures and facilitates that radiation is excreted through body fluids. No visitor is allowed during active therapy and all needs of the patient are fulfilled by healthcare staff.
