Once a high-uptake-hyperthyroidism is diagnosed then the most important next step is for a patient to decide among the available three treatment options. During the first 6 months after a treatment strategy is chosen, there can be many visits with your physicians at Houston Thyroid and Endocrine Specialists. Generally an endocrinologist should be the primary physician in charge of diagnosis and the treatment of hyperthyroidism during the first 6 - 12 months of diagnosis.The thyroid glossary and endocrinology conditions review unfamiliar terminology. The basic treatment of high-uptake-hyperthyroidism may include some or all of the below management strategies:
Here we review the chronology of possible treatment options for high-uptake-hyperthyroidism with a general hypothetical timeline for a patient. The actual series of steps will depend on a patient's specific circumstances and clinical information. In all cases your Houston endocrinologist should direct your care and answer your questions.
First step: Biochemical Confirmation of Thyroid Hormone Excess
Blood testing will be ordered by your endocrinologist if you have signs or symptoms suggestive of hyperthyroidism. A full thyroid panel including the TSH value will be ordered to confirm a diagnosis of thyrotoxicosis.
Diagnostic decision step: Radioactive Iodine Diagnostic Scanning
Radioactive iodine 123-I is the main imaging substance used to determine the functional activity of the thyroid gland. This is a two-day test which requires the use of an imaging camera called a gamma camera. If a patient has been taking PTU or methimazole prior to the scan, their endocrinologist may ask them to discontinue these medications prior to the scan. The patient swallows an extremely small amount of I-123 as a capsule with a glass of water. Four hours after the capsule is ingested, a scan is performed. The patient will go home and return 24 hours later for another scan. Each scan takes approximately 20 minutes. Thyroid ultrasound may be indicated and completed by your endocrinologist if indicated by the thyroid scan and uptake.
Treatment decision: Three Treatment Options
This is a final decision that your physician cannot make for you. The pros and cons of the three major ways to treat your hyperthyroidism will be presented by your endocrinologist in great detail. These have been the only three treatment options for high uptake hyperthyroidism for many years. There may be new treatments in the future, but none are available yet. The risks and benefits of radioactive iodine versus thionamide medications versus surgery will be discussed in detail at your clinic visit. Pregnant women and those that are breastfeeding cannot use radioactive iodine as a treatment option.
(PTU or Methimazole)
Initial step: Start medication:
There are a number of side effects from these medications that can occur in up to 13% of patients. Your endocrinologist will will review with your in your clinic visit. The risks include:
Liver failure - dose dependent and more likely with PTU. The PTU risk incidence 1:10,000 adults and 1:2,000 children)
Sudden inability to fight infection called agranulocytosis (0.5% risk).
Rash, nausea, abnormal taste sensation, fever, anemia, low platelets (5% risk).
Follow up visits:
The dose will not remain the same for the duration of therapy. How long a patient will need therapy is not predictable. Periodic visits during the year are required to monitor for all the potential sideffects of these medication and for dose adjustments. Only about 20% of patients will have a prolonged remission. The patients more likely to have remission are those with small goiter, women, mild hyperthyroidism, age over 40, cessation of smoking, development of hypothyroidism while on medication, and high TPO antibodies. Note- the recurrence rate of hyperthyroidism despite treatment with these medications is 50-60%.
Radioactive iodine therapy is only still an option while taking these pills if a patient is still hyperthyroid and has a high uptake on a thyroid scan.
Initial step: Eye Preparation:
If a patient has significant hyperthyroid eye disease called Graves Opthalmopathy (GO), they may be referred to a neuro-ophthalmologist.
A dose in the 10 to 25 millicurie range of radioactive iodine 131-I will be given in capsule form. The dose will depend on the size of the thyroid and the amount of uptake on the diagnostic scan. Appropriate radioactive iodine treatment precautions should for safety should be followed. The patient will not be admitted to a hospital and should be able to go home after the treatment.
Administration of doses of radioactive iodine sufficient to induce hypothyroidism is associated with significantly improved survival compared with doses of I-131, which render subjects euthyroid or with treatment with antithyroid drugs only. There are a few common side effects. A large study from 2015 did not show an increase in cancer risk from the use of radioactive iodine for hyperthyroidism.
Follow up visits:
There is generally a 70-80% chance that a patient will develop hypothyroidism after treatment with radioactive iodine. The treatment can take up to 6 months to have its full effect. Occaisionally thionamide medications may be needed temporarily. Your endocrinologist at Houston Thyroid and Endocrine will check thyroid function panels and meet with you every 4 - 6 weeks to try to decide when and if thyroid hormone therapy is required for the treatment of hypothyroidism. We advise against pregnancy for at least 6 months have passed from initial treatment dose.
Once a patient is hypothyroid then a thyroid blood test should be checked intermittently to ensure a safe range.
Initial step: Meet with Surgeon:
Surgery is occasionally offered to treat hyperthyroidism in those with very enlarged thyroid glands or who would otherwise not be candidates for therapy using medications or radioactive iodine. One hundred percent of patients that undergo surgery will become hypothyroid and will require medication for hypothyroidism. Medication therapy of hypothyroidism generally carries less side effects than the medications for hyperthyroidism. Surgery would be the quickest management of hyperthyroidism due to toxic multinodular goiter, Graves disease, or toxic hot nodule. The risks of surgical management for these forms of hyperthyroidism the rare side effect of permanent or temporary hypocalcemia from hypoparathyroidism, general anesthesia risks, and general surgical risks. The endocrinologists at Houston Thyroid and Endocrine will refer you to experienced head and neck surgeons. The side effect may also include weight gain in some patients who become hypothyroid
The surgeon you are referred to will plan your surgical date. Generally these types of thyroid surgeries are well tolerated and usually require less than a week in the hospital and most patients are ready to return to work within weeks.
Post Surgery Adjustments:
Your thyroid levels will run low immediately after the surgery and your endocrinologist will check thyroid function panels and meet with you every intermittently to try to adjust your levels to the right place. After the correct dose is reached then you will only need to meet with your endocrinologist once yearly.
Once a patient is hypothyroid, then a thyroid blood test should be checked intermittently to ensure a safe range.