Radioactive Iodine (Radioiodine) Therapy

Radioiodine therapy uses iodine-131, swallowed as a capsule or liquid. The thyroid is the only tissue that concentrates iodine strongly, so the radiation is delivered almost entirely to thyroid cells, which are gradually destroyed over weeks.

In low doses it treats an overactive thyroid from Graves' disease or toxic nodules. In higher doses after thyroidectomy it destroys remaining thyroid tissue and iodine-avid thyroid cancer cells. It does not work for medullary or anaplastic thyroid cancer, and after treatment for overactivity most people become underactive and need lifelong levothyroxine.

What Radioactive Iodine (Radioiodine) Therapy involves

Preparation matters more than the treatment itself. For thyroid cancer you follow a low-iodine diet for 1 to 2 weeks, and your TSH is raised either by injections of recombinant TSH on the two days before or by stopping thyroid hormone for several weeks. For hyperthyroidism, antithyroid tablets are paused for a few days. A pregnancy test is done where relevant. You then swallow the capsule with water under the supervision of the nuclear medicine team. After high doses you stay in a shielded single room until radiation readings fall, and a whole-body scan a few days later shows where the iodine was taken up.

Who is a good candidate for Radioactive Iodine (Radioiodine) Therapy?

The dose and the need for treatment are set by an endocrinologist and nuclear medicine physician from your diagnosis and risk category.

• Graves' disease that has relapsed after tablets or where tablets are not tolerated
• Toxic multinodular goitre or a single overactive nodule
• Intermediate and high-risk papillary or follicular thyroid cancer after total thyroidectomy
• Thyroid cancer that has spread to lymph nodes, lungs or bone and still takes up iodine

It is usually not the right choice if:

• Pregnancy and breastfeeding, which are absolute contraindications
• Women planning pregnancy within 6 to 12 months, or men planning to father a child within about 4 to 6 months
• Active moderate or severe thyroid eye disease, which radioiodine can worsen, particularly in smokers
• Very low-risk small thyroid cancers, where it adds no proven benefit

Technique options

• Low-dose treatment for hyperthyroidism: A single outpatient capsule. The thyroid settles over 6 to 16 weeks; about 10 to 20 percent need a second dose.
• Remnant ablation after thyroidectomy: A moderate dose to clear leftover normal thyroid tissue and make follow-up with thyroglobulin blood tests more reliable.
• Adjuvant or therapeutic high dose: For known or likely residual cancer or distant spread. Needs isolation for a few days and may be repeated.
• Recombinant TSH versus hormone withdrawal: Injections avoid weeks of hypothyroid symptoms and suit most patients; withdrawal is still used in some metastatic cases.

What happens during your treatment

Taking the capsule takes minutes and you feel nothing. No anaesthesia is involved. After a high dose you spend 2 to 4 days in an isolation room with your own bathroom, encouraged to drink plenty, shower daily and suck sour sweets to protect the salivary glands. Visitors are restricted. After a low dose you go home the same day.

Preparing for your trip

For hyperthyroidism a visit of 2 to 4 days covers assessment, uptake scan and the dose, but you must be able to keep distance from others on the way home. For thyroid cancer allow 7 to 10 days for preparation, isolation and the post-therapy scan. Airline travel soon after a high dose may be restricted, and you will need a certificate for border radiation detectors.

• Tell the doctor about medication, allergies, pregnancy or breastfeeding, and any history of cold sores, keloid scars or autoimmune disease
• Avoid alcohol, aspirin and anti-inflammatory painkillers for a few days beforehand if your own doctor agrees, to reduce bruising
• Arrive without make-up on the treatment area and avoid sunbeds and strong sun for two weeks before

Recovery and results

For 1 to 3 weeks, depending on dose, you keep your distance from children and pregnant women, sleep alone, and follow hygiene rules because iodine leaves in urine, sweat and saliva. Neck tenderness, a dry mouth or altered taste can last a few days to weeks. Thyroid blood tests are checked at 6 to 8 weeks and levothyroxine is started or adjusted.

• Back to everyday activity: Distance precautions for 1 to 3 weeks
• When results show: Thyroid levels change over 6 to 16 weeks
• How long they last: Usually permanent

Safety, risks and revision policy

Radioiodine has been used since the 1940s and is considered safe, but it has predictable effects you should know.

• Permanent underactive thyroid after treatment for hyperthyroidism, which is expected rather than a complication
• Temporary neck swelling or tenderness from radiation thyroiditis
• Salivary gland swelling, dry mouth or taste change, mainly after high doses
• Flare of thyroid eye disease, reduced by a steroid course in those at risk
• Temporary worsening of thyroid overactivity in the first weeks
• Transient fall in blood counts or fertility markers after repeated high doses
• A very small increase in lifetime risk of second cancers after high cumulative doses

Every written proposal arranged through Clinic-Y states what the clinic covers if a correction is needed. Ask for it before you book, not after.

Cost of Radioactive Iodine (Radioiodine) Therapy in Türkiye

Clinic-Y does not publish a single price for Radioactive Iodine (Radioiodine) Therapy, because the honest figure depends on your case. What moves it:

• Dose of iodine-131 prescribed
• Nights in a shielded isolation room
• Use of recombinant TSH injections
• Pre-treatment uptake scan and post-therapy whole-body scan
• Blood tests and endocrinology follow-up

Send your photographs or reports and you receive written, all-inclusive proposals from suitable teams, side by side. Reviewing your case is free.

Frequently Asked Questions