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Thyroid Ablation Instructions

Please follow these diet restrictions for two weeks before your radioactive iodine (I-131) treatment: 

  • Stop eating the following foods:
    • Vitamins that contain iodine (if you are not sure, do not take them)
    • Seafood
    • Iodized salt, sea salt
    • Canned soups and sauces
    • Chocolate
    • Soy Sauce
    • Processed meats including hotdogs, lunch meat, bacon, ham, corned beef, sausage, and canned meats
    • Sauerkraut
    • Bread, pancake, and muffin mix
    • Molasses
    • Foods that contain red dye
    • Foods that have "iodated" listed as an ingredient 
  • Cut down the following foods to no more than 2 servings per day
    • Milk
    • Yogurt
    • Ice Cream
    • Non-dairy coffee creamer
    • Eggnog


After Care Information: 

  • Do not bring other children to ablation. They should not ride in the car with the patient to or from the appointment.
  • Your child will miss school for 7 days
    • Contact your Human Resources department or our social worker if FMLA paperwork needs to be completed.
  • The child may not attend activities with children, including church, sports, etc. for 7 days after the ablation.
  • Your child must sleep in a separate room with him/herself for 7 days after the procedure.
  • Your child should use a separate bathroom from other family members if possible for 7 days. In addition, he or she should flush toilet 2 times with the top down and wipe down the toilet and sink with water after each use for those 7 days. Boys are advised to urinate sitting
  • Rinse the bathroom sink and bathtub with water after use. Thoroughly clean your child’s bathroom on the 8th day after treatment.
  • Maintain a two arm span distance (approximately 1 meter) around others for the first three days after procedure (No hugs in the first 3 days).
  • Encourage your child to drink plenty of water or other liquids to help get rid of the radioiodine in the urine. Frequent urination will reduce radiation to his/her bladder. Encourage sucking on sour or lemon candy to decrease radiation to the salivary glands. At least one bowel movement daily will limit colon exposure.
  • Your child may be given laxative therapy to assure at least one bowel movement every day to limit radioiodine exposure to the colon.
  • Have your child wash his/her hands with soap and water each time he/she use the bathroom. Take at least one shower daily.
  • Make sure to wash eating utensils well after use or use disposable eating utensils for the first three days. Do not let your child bite their nails or put objects (like pencils, necklaces) in his/her mouth.
  • Use a washcloth, towels, bath soap and wash clothes separately from other family members’ clothes.


Transportation Information: 

  • Do not bring other children to the ablation. They should not ride in car with the patient from the appointment.
  • Your child should come to the ablation appointment with as few family members as possible. No other children are permitted to come to the appointment with the with the patient.
  • Your child may not be transported to or from the ablation appointment on a bus or any other public transportation (including Kid One).

Serum Pregnancy test on the day of the ablation if menstruating or teenager 

  • A pregnancy test must be conducted just prior to the ablation.
  • This test is required for girls who are menstruating or in pubertal years.


Admission Information:

  • Patient should not eat or drink for 2 hours prior to administration of the I-131.
  • For Grave’s Disease patients, the ablation is an outpatient procedure.
  • For Thyroid Carcinoma patients, you will be admitted to the hospital for at least 24 hours. Once you register and have been interviewed by Nuclear Medicine, the technologist will take you to admitting.

Medication Information:

Medications to Discontinue

Type of Medication                                                  Recommended time of Withdrawal


Antithyroid Medications (e.g., Propylthiouracil,

Methimazole, Carbimazole)                                                                      5 days

Multivitamins containing iodine                                                                 7-10 days

Natural or synthetic thyroid hormones                                                      10-14 days for triiodothyronine

                                                                                                                  3-4 weeks for thyroxine

Kelp, agar, carrageenan, Lugol’s solution                                                 2-3 weeks

Saturation solution of potassium iodide (SSKI)                                         2-3 weeks

Topical iodine (e.g., surgical preparation)                                                 2-3 weeks

Intravenous radiographic contrast agents

         Water soluble                                                                                   6-8 weeks assuming normal renal function


         Lipophillic                                                                                        1-6 months

         Amiodarone                                                                                     3-6 months or longer


Always follow your doctor’s instructions regarding your medication withdrawal

Follow Up: 

  • Follow up with Pediatric Endocrinology 6 weeks after the procedure or as discussed with your endocrinologist. This return appointment will be made by our office once your procedure is scheduled.
  • Your doctor will give you further instruction about giving medicines after the ablation based on lab results.


Frequently Asked Questions:


  • What is Radioiodine?
    • Radioiodine is a radioactive form of iodine (Iodine 131 or I-131) used in the diagnosis and treatment of various thyroid conditions including hyperthyroidism and thyroid cancer. Radioiodine treatment is given after you and your doctor have agreed that it is the best option for your condition. If you have questions regarding alternative treatments available, you are advised to discuss it with your doctor.
  • How dose radioiodine work?
    • The thyroid gland accumulates dietary iodine to make thyroid hormones which are essential for normal bodily function. Radioiodine is similarly taken up by the thyroid or left over thyroid gland tissue after thyroid surgery. The radiation emitted in turn decreased the function and/or growth of the thyroid cells, which is the desired medical effect. This effect occurs usually between one and three months after treatment. For hyperthyroidism usually, a single dose is sufficient, however occasionally retreatment may be needed.
  • Am I radioactive after Radioiodine treatment?
    • You should plan to follow radiation safety precautions to protect those around you. If you have any questions about these instructions, you should call the Nuclear Medicine Doctor on-call at 205-638-9730 or through the page operator at night 205-638-9100.
  • Is this a safe and effective treatment?
  • Radioiodine treatment is known to be safe and effective and has been used for several decades all over the world.
  • How is Radioiodine administered?
    • It is administered orally (by mouth) as a capsule in variable quantities depending on the diagnosis. If you are unable to swallow a capsule, a liquid formulation is also available.
  • What are the side effects of Radioiodine treatment?
    • Treatment is usually well tolerated. Occasionally there may be mild pain in the region of the thyroid gland. Radiation to the salivary glands may cause temporary dry mouth and alteration in taste. Mild nausea and vomiting are not uncommon and are treated easily. Rarely there may be permanent damage to the salivary glands. There is a slight increase in risk of future malignancies especially after Radioiodine treatment for thyroid cancer, including leukemia, cancers of the stomach, urinary bladder, colon and salivary glands. These late side effects are rare and should not deter the appropriate patient from taking Radioiodine treatment.
  • What are the long term effects of this treatment on the thyroid gland?
    • Usually, most or all of your thyroid gland will be destroyed with this treatment; therefore you will likely require taking daily thyroid hormone replacement (levothyroxine) for the rest of your life. Thyroid hormone replacement is usually safe and well tolerated under supervision.


If you have any questions, feel free to contact our office. Pediatric Endocrinology at 205-638-9107.

The building that COA Nuclear Medicine is located is the Benjamin Russell Building at 1600 5th Avenue South.

It is on the 1st floor of Benjamin Russell. Park in the 5th Ave parking deck and cross over on the 2nd floor then take the glass elevator to the 1st floor.

The phone number to COA Nuclear Medicine is 205-638-9667 if you have any questions.