Radioactive Iodine

We understand that the journey through thyroid cancer treatment can be overwhelming, and we want to provide you with comprehensive information about the recommendations, protocol, benefits, and potential side effects of radioactive iodine therapy. This treatment is designed to target and eliminate any remaining thyroid cells or cancerous tissue after surgery. Please take the time to read through this educational guide, and feel free to discuss any questions or concerns with your healthcare team.


Patient Selection:

Radioactive iodine therapy is often recommended after thyroidectomy, targeting any remaining thyroid cells or cancerous tissue.
Your healthcare team will assess your specific case, considering factors such as cancer type, stage, and characteristics to determine if this treatment is suitable for you.


You may be advised to follow a low-iodine diet or temporarily stop thyroid hormone medication to enhance the uptake of radioactive iodine by cancer cells.
Staying well-hydrated is crucial to help flush out excess radioactive iodine from your body.

Dosage Determination:

The dosage of radioactive iodine is personalized based on your individual case, including the size and extent of the cancer and the ability of the cancer cells to take up iodine.

Post-Thyroidectomy Timing:

Radioactive iodine therapy is typically administered in 6 to 8 weeks after thyroid surgery to target any remaining cancerous cells.
The timing of the treatment will be carefully planned to optimize its effectiveness.

Protocol for Radioactive Iodine Therapy:

Based on the chosen protocol, either Levothyroxine withdrawal or Thyrogen stimulation is performed before administration of I-131 therapy. Determination of the protocol is chosen by your endocrinologist based on your disease severity and also based on your insurance. Both levothyroxine withdrawal or Thyrogen stimulation are equally efficient, but there are some minor differences that exist.

Patient Education:

You will receive detailed information about the procedure, potential side effects, and safety measures.
It's crucial to follow pre-therapy instructions provided by your healthcare team.

Dosimetry and Planning:

Your healthcare team, including nuclear medicine specialists, will determine the appropriate dosage and plan the therapy based on your unique case.
Safety precautions will be in place to minimize radiation exposure.

Radiation Safety Measures:

Safety protocols will be implemented to protect healthcare providers and the public from unnecessary radiation exposure.
You will receive guidance on precautions to minimize radiation exposure to family and friends.

Isolation Period:

You may need to isolate yourself for a specified period to reduce the risk of exposing others to radiation.
The duration of isolation will depend on the administered dosage.

Benefits of Radioactive Iodine Therapy:

Targeted Treatment:

Radioactive iodine selectively targets thyroid cells, minimizing damage to surrounding tissues.

Reduced Recurrence Risk:

The therapy aims to eliminate any remaining thyroid tissue or cancer cells, reducing the risk of cancer recurrence.

Post-Surgical Management:

Especially effective when complete surgical removal of the thyroid is not possible, it complements surgery by addressing residual cancerous cells.

Improved Survival Rates:

Studies suggest that radioactive iodine therapy can contribute to improved overall survival rates in certain cases of thyroid cancer.

Side Effects and Considerations:

Temporary Symptoms:

You may experience temporary symptoms like nausea, swelling of salivary glands, or a metallic taste in your mouth.

Radiation Exposure:

Your healthcare team will address concerns about radiation exposure to you and your close contacts.

Thyroid Hormone Fluctuations:

The therapy may impact thyroid hormone levels, requiring ongoing monitoring and potential adjustments to hormone replacement therapy.

Secondary Cancers:

Long-term surveillance is essential to monitor for potential risks of developing secondary cancers associated with radiation exposure.

Reproductive Considerations:

If you plan to conceive, discuss fertility considerations and appropriate precautions with your healthcare team.
Remember, this information provides a general overview, and your healthcare team will tailor the treatment plan to your unique circumstances. Open communication with your healthcare providers is key to ensuring the best possible outcome in your thyroid cancer journey. Please feel free to ask any questions and express any concerns you may have along the way.

There are other resources available to patients with thyroid cancer who are undergoing therapy with I-131, such as Dosimetry. Dosimetry calculates the maximal I-131 doses needed for your specific therapy.