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.
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.
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.
- 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.
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.