IODINE - 131
Benign Thyroid Conditions
Procedure description:
Radioactive Iodine (RAI) or I-131 oral capsule has been used for benign and malignant disorders of the thyroid since the 1940s. I-131 is administered orally for the treatment of Graves disease, toxic nodules, as well as toxic and non-toxic multinodular Goiter. This therapy may be used successfully to diminish the size of a non-toxic nodular Goiter, especially when surgery is contra-indicated or refused.
For hyperthyroidism, the goal of this therapy is to attain a non-hyperthyroid status, either a euthyroid state or iatrogenic hypothyroidism. For a large non-toxic nodular Goiter, the primary goal is the reduction of thyroid volume to relieve compressive symptoms in the neck.
Patient preparation:
The patient must discontinue the use of iodide-containing medications and preparations including avoiding food that contains iodized salt and red dye, as well as dairy products, eggs, seafood, and soy. The patient should not eat as of 10 pm the night before, but may drink only water. Iodide-containing medication or preparations could potentially affect the ability of the thyroid tissues to accumulate treatment Iodine.
The patient is required to stop thioamides or anti-thyroid medication such as methimazole, and carbimazole 5 days prior to the treatment. The patient may be placed on beta-blockers for symptomatic control, which need not be discontinued for the purpose of RAI treatment.
The patient is not required to stop medications for diabetes mellitus, high blood pressure, asthma, heart failure, and/or any other essential medications.
Any further procedure-specific: treatment, potential complications, side effects, therapeutic alternatives, and expected outcome to the patient will be explained.
Iodine-131 treatment is contra-indicated in pregnant and breastfeeding women.
Malignant Thyroid Conditions
Procedure description:
Treatment with Iodine-131 (ablative therapy) of differentiated thyroid cancer should be considered in the post-surgical management of patients with a tumor diameter greater than 1 cm, or less than 1 cm in the presence of high-risk features. The patient will be required to sign an information and consent form and subsequently, after the oral administration of the Iodine-131 capsule, the patient will be admitted for 3-5 days, in isolation.
Patient preparation:
The patient would be required to undergo near-total thyroidectomy. The near-total thyroidectomy is conducted by a general surgeon and his or her team.
The patient would be required to discontinue thyroid hormone treatment, for a time sufficient to allow TSH to rise above 30 mIU/ml. Triiodo-Thyronine (T3) should be stopped for at least 10-14 days, and Thyroxine (T4) for 4 weeks.
Pre-ablation whole-body scintigraphy for staging should be performed. This is to determine the extent of the residual functional thyroid tissue and confirm or exclude regional metastasis to the lymph nodes, metastasis to the lungs, to the skeleton, or to the brain. With a view to guide the treatment dose and management of potential complications.
The Iodine-131 treatment is contra-indicated in pregnant and breastfeeding women. All women who are age-bearing will be tested for pregnancy.
The patient must discontinue the use of iodide-containing medications and preparations including avoiding food that contains iodized salt and red dye, as well as dairy products, eggs, seafood, and soy. The patient should not eat as of 10 pm the night before but may drink only water. Iodide-containing medication or preparations could potentially affect the ability of the thyroid tissues to accumulate treatment Iodine.
The patient is not required to stop medications for diabetes mellitus, high blood pressure, asthma, heart failure, and/or any other essential medications.
Any further procedure-specific: treatment, potential complications, side effects, therapeutic alternatives, and expected outcome to the patient will be explained.