Anaplastic Thyroid Cancer Radioactive Iodine And Side Effect

Radioactive iodine is one of the many steps in treating thyroid cancer also called thyroid ablation or thyroid cancer treatment. Radioactive iodine ablation (RAI) is indicated when treating differentiated thyroid cancer that has spread beyond the thyroid.

Thyroid cancer can be staged with the AJCC/UICC or with the NTCTCSG system which can predict disease mortality and help to plan for possible radioactive iodine. So far, there is not a perfect staging system for thyroid cancer. Ideally the best staging system would:

1) provide common descriptors that facilitate communication among physicians and institutions regarding individual patients and patient cohorts
2) allow physicians to estimate the prognosis for any given patient as well as the expected benefit from therapies
3) permit appropriate stratification for the design and analysis of retrospective clinical studies and prospective clinical trials

The NTCTCSG system differs from the AJCC system in that some patients with AJCC stage I disease are advanced to higher stages in the NTCTCSG system. This difference can affect treatment consideration s in up to 50% of patients with differentiated thyroid cancer. As of 2010, the effect of radioiodine therapy on patients with NTCTCSG-defined stage I disease is neutral and not associated with an increase or decrease in survival.

The implication of this finding is that if radioiodine therapy is deemed appropriate to improve accuracy of follow up by thyroglobulin monitoring and radioiodine scanning in certain patients with stage I, the 2010 data shows no detrimental effect of adjuvant radioiodine therapy on patient survivial.

Following a low iodine diet during the 2-3 week period prior to radioactive iodine therapy will make the treatment more effective. This treatment uses radioactive iodine (131I) to destroy leftover microscopic thyroid cancer cells as well as any normal thyroid tissue that might remain after surgery.

Destroying these cells makes it easier for doctors to follow patients for signs of thyroid cancer recurrence. Radioactive iodine treatment is used in most patients with differentiated papillary, follicular and Hurthle cell thyroid cancers. There are specific precautions to take after radioactive iodine is given.

Side effects of Radioactive Iodine Treatment

1. A sore throat may occur a few days after the treatment, which can be treated with acetaminophen.
2. Rarely, the salivary glands may swell, may also cause dry mouth and taste changes, which are caused by the iodine and not the radioactivity. Chewing gum or sucking on hard candy may help with the salivary gland problems.
3. Mild nausea and upset stomach may develop for a few hours after the iodine is taken, so it is best not to eat two hours before and two hours after the iodine administration. If nausea continues, the doctor’s office can prescribe medications to treat the nausea.
4. Neck tenderness and swollen lymph nodes may arise after the treatment and will minimize over time. If it continues, please contact your provider’s office.
5. It is extremely important that women who are breast-feeding stop before the Radioactive Iodine Treatment is given, since iodine is concentrated and excreted in breast milk.
6. Pregnant women should not be treated with Radioactive Iodine Treatment, and pregnancy should be avoided for six months following treatment
7. Tear formation is sometimes reduced in some people leading to dry eyes. If you wear contact lenses, ask your doctor how long you should keep them out.

Suggested guidelines per the 2010 American Thyroid Association Consensus:

• RAI ablation is recommended for all patients with known distant metastases, gross extrathyroidal extension of the tumor regardless of tumor size, or primary tumor size >4 cm even in the absence of other higher risk features
• RAI ablation is recommended for selected patients with 1–4 cm thyroid cancers confined to the thyroid, who have documented lymph node metastases, or other higher risk features (see preceding paragraphs) when the combination of age, tumor size, lymph node status, and individual histology predicts an intermediate to high risk of recurrence or death from thyroid cancer
• RAI ablation is not recommended for patients with unifocal cancer <1 cm without other higher risk features
• RAI ablation is not recommended for patients with multifocal cancer when all foci are <1 cm in the absence other higher risk features

There is no definite way to prevent thyroid cancer because most people with thyroid cancer have no association with the possible risk factors. Genetic testing of familial MTC can be used in families with a history. Families can be screened for the disease and removal of the thyroid can help prevent the development of MTC.