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Your doctor has requested a Radioactive Iodine Ablative therapy for your thyroid cancer. This booklet will answer some of the questions you may have. 

When is Radioactive Iodine Ablative therapy used? 

Radioactive Iodine Ablative therapy is a common way to treat differentiated forms of thyroid cancer (papillary and follicular). It destroys any leftover thyroid tissue or cancer that the surgeon was not able to remove during the thyroid surgery and thyroid cancer, minimizing the risk of cancer coming back. 

What is a Radioactive Iodine Ablative therapy? 

Radioactive iodine ablation is performed by giving a dose of radiation in the form of a capsule or liquid. This type of radiation is called radioactive iodine. It targets and destroys any remaining thyroid tissue or tumor cells that may be present in the body. This procedure is usually done several weeks after the thyroid surgery. Your doctor will also request a test called a Whole-Body Iodine Scan as part of the procedure. 

What is involved? 

Before your therapy is scheduled, you will be consulted by a doctor knowledgeable on the treatment regarding the risks and benefits of having the radioactive iodine ablative treatment. At this time, you will be given specific instructions about all the preparation that is required for a successful treatment and the precautions that need to be followed. You will be asked to sign a consent form. Your appointments will be booked by the Nuclear Medicine Department based on your treatment regimen. 

When you arrive in the department for your therapy, a technologist will explain the entire procedure to you and give you the opportunity to ask any questions. A doctor will ensure that you are receiving the correct amount of radioactive iodine that was ordered for you and answer your questions. The technologist will then give you the dose either in the form of a capsule or liquid. Once you have received this dose, you will be able to leave the department. Occasionally the treatment may make you nauseated which you could take gravel for prevention. The entire procedure will take about 30 minutes. 

You will be given an appointment to return to the Nuclear Medicine Department five days after therapy for a whole-body iodine scan. When you arrive for your scan, a technologist will explain the entire procedure to you and answer any questions you may have. You will be asked to take off all external metal from your body and/or change into hospital gowns as appropriate. The technologist will ask you to lie down on an imaging bed and a special detector, called a gamma camera will scan your body from your head to your feet. We will also take specialized three-dimensional images of specific areas of your body. The entire procedure will take about 1.5 to 2 hours. 

Do I need to prepare for the treatment? 

Bring your Health card. 

The instructions given in this section are for general information only. Very detailed and specific instructions will be given to you during your consultation appointment. 

For the therapy to work effectively, you need to have a high level of thyroid stimulating hormone (TSH) in the body. TSH stimulates thyroid cells to absorb radioactive iodine. If you have started thyroid hormone replacement therapy after surgery, the doctor may stop the medication to allow the TSH levels to rise (also known as thyroid hormone withdrawal). This can cause you to experience symptoms of hypothyroidism. As an alternative to thyroid hormone withdrawal, your doctor may use a prescription medication (called Thyrogen) that increases TSH levels without stopping thyroid hormone replacement. If your doctor decides to put you on the Thyrogen regimen, you will be given a prescription to pick up Thyrogen from your pharmacy. You will also be given two appointments over two consecutive days to receive your Thyrogen injection in the Nuclear Medicine Department or your Doctor’s office. 

For either regimen, it will be recommended that you go on a Low Iodine Diet. This is to induce a state of iodine deficiency in your body, so that the radioactive iodine can be absorbed efficiently. Specific instructions and information will be given to you so that you can plan your diet. 

There are certain medications that interfere with the therapy. You will be given specific instructions regarding which medications need to be stopped.  

Women of childbearing age will be required to get a blood test done on the morning of their therapy, to ensure that they are not pregnant. The nuclear medicine department will give you specific instructions about when and where to have this blood work done. Hysterectomy and menopause are the only acceptable reasons not to have the blood test done. 

Breastfeeding: Iodine is excreted in breast milk. In order to minimize radiation dose to the breasts, RAI therapy should be delayed for 3 months after stopping breastfeeding). Breastfeeding must be stopped following treatment. 

What are the Side Effects? 

The instructions given in this section are for general information only. Very detailed and specific instructions will be given to you during your consultation appointment. 

1. Thyrogen: 

• Thyrogen can stimulate residual thyroid tissue to produce more thyroid hormone, possibly aggravating underlying heart disease. 

2. Thyroid hormone withdrawal: 

• You may experience hypothyroid symptoms such as fatigue, insomnia, poor concentration, anxiety, depression, bloating, cold intolerance, constipation and weight gain. 

3. Radioactive Iodine Ablation: 

• You may experience sore throat, nausea and vomiting, swelling and tenderness of the salivary glands, dry mouth, taste changes and dry eyes. 

Is it safe to conceive after Radioactive Iodine Ablative therapy? 

There is no evidence of reduced fertility or genetic abnormalities in patients’ offspring after RAI. However, as a general precaution following radioactive iodine treatment, men should avoid fathering a child for at least four months, and women should avoid conceiving for at least six months. Your treatment center will give you detailed information on this. After that time there is no problem with having a baby or with the development of the baby and many people have gone on to conceive and have healthy children following treatment with radioactive iodine. 

Is the radiation dangerous? 

Large follow-up studies have been carried out for more than 70 years in many European countries and the United States. These show that there is an extremely small excess risk of cancer from ablative treatment with radioactive iodine. For most patients, the benefit of treating thyroid cancer far outweighs the extremely low cancer risk. The specialist doctors who will be treating you will be able to answer any questions you have about the safety of treatment in your situation. 

Do I need to do anything after the Treatment? 

In the days following radioactive iodine therapy, you will need to take certain precautions to prevent radiation exposure to others. Keep in mind that the precautions listed below are general, and your doctor will be more specific about how many days and what kinds of precautions you need to follow tailored to your individual needs and medical circumstances. 

The radioactive iodine used for your treatment will remain in your body only temporarily. Most of the iodine not taken up by your thyroid gland will be eliminated during the first few days after your treatment. The iodine leaves your body mainly in your urine, but small amounts also leave in your saliva, sweat and feces. Although there is no evidence that the radiation from this amount of iodine will cause harmful effects, it makes sense to avoid any unnecessary exposure to others. The following simple precautions should be taken following your treatment: 

• When travelling home after treatment, preferably travel alone in a private vehicle or if that is not possible, with one another driver. Maintain as large a distance as possible between you and the driver. 
• Keep distance from others, including mealtimes. 
• Remain in your home for 2 days post-treatment. 
• Delay returning to work unless you can satisfy the above conditions both at work and while traveling to work. 
• Sleep in a separate room. 
• Avoid personal contact with others (hugging/kissing/sexual intercourse). 
• Avoid prolonged physical contact with babies, young kids, pregnant women and pets. 
• Drink plenty of fluids. This will help the radioactive iodine to leave your body more rapidly. 
• Urinate as often as possible. Men should sit to urinate. Use a separate bathroom. Flush the toilet twice (with lid down) after each use. If you do not have a separate bathroom, clean thoroughly before returning it for use by others. Wash your hands with plenty of soap and water after you go to the toilet. 
• Do not share items (food utensils, towels and personal use items) with anyone else. 
• Wash all clothes and bed linens separate from household laundry. 

People who have recently had radioactive iodine treatment can trigger radiation detectors used for security purposes, for example at airports and border crossings. This can occur for up to three months after treatment. If you are travelling within this time period, you should carry a travel letter provided by the nuclear medicine department. 

What about breastfeeding? 

Breastfeeding must be discontinued entirely. It is vital that you ensure that we are aware if you are pregnant and/or breastfeeding. 

Will this treatment cost me money? 

No. This test is paid for by the healthcare system. This treatment costs over one thousand dollars, so please notify the department at 613-761-4831 if you cannot make your appointment. 

What should I do if I cannot make my appointment? 

If you cannot make your appointment, it is important that you notify the department at 613-761-4831 as soon as possible. Failure to make your appointment results in wasting of expensive materials that are ordered especially for your appointment and also reduces availability to other patients. Missed appointments may also result in delays of your treatments. 

Directions and Parking 

Civic Campus  1053 Carling Avenue – 1st Floor Tel.: 613-761-4831, option 8 Hours: Mon. – Fri., 8:00 a.m. – 4:00 p.m. Directions: From within the Civic Campus, take the “C” elevators to the 1st Floor and follow the signs to Nuclear Medicine. Patients may also ask for directions at the patient information desk.	General Campus  501 Smyth Road – Main level Tel.: 613-761-4831, option 8 Hours: Mon. – Fri., 7:00 a.m. – 4:00 p.m. Directions: From the main entrance, follow the signs on the main level (located at the public elevators). Patients may also ask for directions at the patient Information desk.
Park in either parking lot off Carling Avenue (P7) or in the multistory parking garage (P1).	Park in the parking garage which is located beside the main entrance just off Smyth Road.

Parking instructions 

• All parking lots are automated  
• Take the parking ticket with you inside.  
• When you have completed your appointment, you can pay by cash or credit card at one of our pay stations, or you can pay by credit card with express exit at the parking lot exit gates (the grace period after payment to leave facility is 20 minutes). 
• Payment methods: 
  • Pay stations: Cash or credit card (Visa, MasterCard or American Express). 
• Maximum parking fee is $13.00 

Visit The Ottawa Hospital’s website for additional directions and parking instructions and maps 

Last updated on: April 21st, 2022