1. Low Dose Iodine-131 THERAPY for Hyperthyroidism

What is radioactive iodine?

Radioactive iodine is an effective method of treatment. It is being used more often than surgery when definitive (permanent) treatment is needed. Radioactive iodine is taken up by the thyroid gland and destroys its cells. This has the effect of reducing the amount of thyroid hormone made by the thyroid gland and may also reduce the size of the gland.

When is radioactive iodine treatment used?

• As treatment for an overactive thyroid gland, with or without prior antithyroid drug therapy, especially in people with toxic nodular hyperthyroidism
• As treatment for Graves’ disease either because the disease fails to settle after antithyroid medication, or returns after stopping antithyroid medication, or if patients do not tolerate antithyroid medication. It can also be considered early after diagnosis of Graves’ disease should patients wish to have the treatment at this stage

Is it safe to conceive after radioactive iodine treatment?

Following radioactive iodine treatment men should avoid fathering a child for at least six months, and women should avoid conceiving for at least six months.

Who should NOT have radioactive iodine treatment?

Radioactive iodine treatment is not given to:

• Pregnant women
• Breast-feeding women
• Anyone who is regularly vomiting or incontinent
• People with active thyroid eye disease as it may worsen the eye disease unless steroids are given at the same time
• If the thyroid gland is very overactive, radioactive iodine can cause dangerously high levels of thyroid hormone and, very rarely, a condition known as thyroid crisis or storm

Your doctor will therefore prescribe antithyroid drugs to control the thyroid overactivity first before giving you radioactive iodine.

How is radioactive iodine taken?

Your treatment will take place in hospital but you do not need to be admitted to hospital as an inpatient. The treatment and its effects will be discussed at the hospital before the radioactive iodine is given and you will be asked to give your consent to the treatment. The dose is taken either as a simple capsule or as a drink. The gland has to be working when this treatment is taken, so antithyroid tablets should be stopped usually at least one week before the treatment is given. You will be given instructions on when to stop the tablets. You may also be asked to use beta-blockers to relieve any temporary symptoms of hyperthyroidism. Your doctor will discuss with you before treatment whether you should restart the medication afterwards and when.

What happens after radioactive iodine treatment?

Follow-up after radioactive iodine treatment is essential. There is no single correct dose and about 10% of patients need a further dose. There are no additional problems associated with having more than one dose. Some patients will still require treatment with antithyroid medication for some weeks or months until the radioactive iodine has been effective and the overactivity has settled.

Over two-thirds of those who have radioactive iodine treatment will develop hypothyroidism (an underactive thyroid). This can occur anytime from one month after the treatment and is most common within the first 12 months after treatment but can occur later. You should have a blood test about four to six weeks after treatment, and should then be checked every one to three months in the first year - usually by hospital clinic. It is very important not to miss these checks even if you feel well, as they can pick up an underactive thyroid before you have symptoms. After that you should see your GP for an annual blood test, or at any time beforehand, if symptoms of hypothyroidism develop. It is usually straightforward to treat an underactive thyroid gland. Levothyroxine, which is thyroxine in tablet form, is used to replace the thyroxine that your thyroid gland is unable to produce.

What about radioactive iodine treatment for children and teenagers?

Radioactive iodine is an effective and safe treatment option for children and teenagers with an overactive thyroid gland, but will usually be given as a second-line treatment after a reasonably long course of antithyroid medication. It is used less commonly in younger children.

2. High Dose Iodine-131 THERAPY for Thyroid Cancer

What is I-131 treatment?

I-131 is a radioactive substance that is taken up by certain type of thyroid cancer cells and destroys these cancerous cells.

It is known to be effective in:

• Certain types of thyroid cancer (Differentiated thyroid cancer) Any I-131 that is not absorbed by the tumor cells passes out of your body in your sweat, saliva, urine and stool. The I-131 that is trapped in the tumor cells leave the tumor and are passed from your body.

Investigations that will be needed for the treatment

• You need a scan before the treatment known as low dose Iodine scan which you may have had done already.
• You will need tests which your doctor will arrange for you, as follows:
  • Blood tests 2 weeks before the treatment

Is there any preparation before the treatment?

Ensure that if you are taking thyroid hormone tablets or any iodine containing preparation this is stopped 4 weeks before treatment.

How is I-131 treatment given?

Before this treatment, you should have as little to eat as possible for at least two hours. The treatment itself involves swallowing either liquid (through a straw) or capsules of radioactive Iodine-131. Additionally, you will be requested not to eat for at least two hours after the therapy, if possible.

Are there any side effects?

Possible side effects of treatment are slight nausea, swelling in the neck region and tenderness in your salivary glands.

Possible future health risks from this treatment that an average patient are the development of hypothyroidism (underactive thyroid gland) and a minimal increased risk of cancer induction due to radiation. Additionally, if cancer of the thyroid extensively involves lungs, as a result of this therapeutic procedure, pulmonary fibrosis, pulmonary edema or radiation pneumonitis are possible future health risks to me.

3. Lu-177 DOTATATE THERAPY

What is Lu-177 treatment?

Lu-177 is a radioactive substance that we can add to a carrier called DOTATATE. Lutetium-177 is an atom that sends out radioactive particles. Octreotate joins to your neuroendocrine tumor with the radioactive Lutetium atom attached to it. Once in your body, the Lu-177 DOTATATE attaches to specific tumour cells and destroys these cancerous cells.

It is known to be effective in:

• Neuroendocrine tumours
• Paragangliomas, neuroblastomas
• Certain types of thyroid cancer

  Any Lu-177 DOTATATE that is not absorbed by the tumor cells passes out of your body in your sweat, saliva, urine, and stool. The Lu-177 DOTATATE that is trapped in the tumor cells leaves the tumor and is passed from your body.

Investigations that will be needed for the treatment

• You need a scan before the treatment known as octreotide scan or Ga-68 DOTATATE PET/CT which you may have had done already.
• You will need tests which your doctor will arrange for you, as follows:
  • Blood tests 2 weeks before the treatment
  • Blood tests around 2 weeks after the treatment

Is there any preparation before the treatment?

Ensure that if you are taking a depot somatostatin analogue preparation this is stopped 4 weeks before lutetium treatment. You may require subcutaneous octreotide (100mg tds and increase according to symptom control) in the interim.

How is Lu-177 treatment given?

You will be given medicine to prevent nausea. The treatment is given through a drip into your vein over the course of one hour. You will also receive a fluid solution containing amino acids through another drip over four 4 hours to protect your kidneys from the effect of radiation. The Lu-177 DOTATATE will then be given. The Lu-177 DOTATATE takes 60 minutes to infuse.

4. Lu-177 PSMA THERAPY

What is Lu-177 treatment?

Lu-177 is a radioactive substance that we can add to a carrier called Prostate specific membrane antigen (PSMA). Lutetium-177 is an atom that sends out radioactive particles. PSMA joins to your prostate tumor with the radioactive Lutetium atom attached to it. Once in your body, the Lu-177 PSMA attaches to specific tumour cells and destroys these cancerous cells.

It is known to be effective in: prostate cancer.

Any Lu-177 PSMA that is not absorbed by the tumor cells passes out of your body in your sweat, saliva, urine and stool. The Lu-177 PSMA that is trapped in the tumor cells leave the tumor and are passed from your body.

Investigations that will be needed for the treatment

• You need a scan before the treatment known as Ga-68 PSMA PET/CT which you may have had done already.
• You will need tests which your doctor will arrange for you, as follows:
  • Blood tests 2 weeks before the treatment

Is there any preparation before the treatment?

Ensure that if Taxane-based chemotherapy is paused for at least 4 weeks.

How is Lu-177 treatment given?

You will be given medicine to prevent nausea. The treatment is given through a drip into your vein over the course of one hour. You will also receive normal saline drip and diuretic injection. The Lu-177 PSMA will then be given. The Lu-177 PSMA takes 30-60 minutes to infuse.

Are there any side effects?

The most reported side effect is nausea but we will give you an injection before the treatment to prevent this and we will give you tablets to take home.

Other reported side effects are:

• Temporary reduction in blood count and white cells
• A reduction in salivary gland function
• A reduction in kidney function
• Fatigue