Radioactivity: information for patients and parents of patients younger than 18

Your physician has referred you or your child to the Nuclear Medicine Department for a test involving a light dose of radioactive tracer and possibly X-rays.

Together with your physician and the physicians on our department, we make sure that the benefits of this test far outweigh any possible risks.

Find out more about radioactivity and X-rays here. This information falls under the duty of disclosure to which our physicians are legally obliged by the Federal Agency for Nuclear Control.

You can visit the following FANC websites for more detailed information:

• Medical applications of ionising radiation
• Economical use of radiation

If you have any other questions, do not hesitate to ask our staff with the Nuclear Medicine department.

X-rays are a form of radiation, just like the light around us is. They have a higher energy, however, which allows them to penetrate the body. This is how we can use our lightly radioactive tracers and devices to image your skeleton and organs.

The radiation dose we use is very limited. Therefore, the health risk for adults is negligible. Both the devices and the dose used are subject to strict legislation and regular checks. Only with frequently repeated testing, particularly in very young patients, is there greater risk of developing cancer from radiation. This is because although the risk is very low, it is cumulative. Compared to adults, very young patients have greater sensitivity to radiation. However, the physician who requested the test and the physicians in the Nuclear Medicine Department ensure that the added value of this test for you or your child far outweighs any possible risk. This is called the ‘testing justification'. Therefore, we only perform tests that are necessary and keep the radiation dose for each test as low as possible while still producing high-quality of diagnostic imaging. For most nuclear medicine tests, the radioactive tracer dose can be further reduced in the body by drinking sufficient fluids on the day of the test. Frequent urination further reduces the dose. If your child was given a tracer, we recommend changing wet nappies frequently on the day of the test.

There is no legal limit on the maximum number of tests you can have. These are low radiation doses, for diagnostic purposes only. This is not to be compared with doses that are common with radiation therapy (e.g. for treating cancer with radiation). We weigh the advantages with the possible risks every time we consider a test. As long as this test is advantageous for the patient, it may be performed.

Not all tests use the same radiation dose. The radiation dose depends on the type of test. The SPECT camera in our department does not emit any radiation. The machine only detects radiation that is emitted from a mildly radioactive tracer that has been administered to you or your child. For some tests, a CT scan is performed at the same time. The machine very briefly emits a limited amount of X-rays. The nurse will tell you if this is the case. For the most common test performed in our department, the SPECT/CT of the skeleton, the radiation dose varies between 5 - 12 mSv. This is comparable to exposure to the natural background radiation in Belgium over the time period of two to five years. Many tests actually use a much lower dose of radiation.

Pregnant women must inform their requesting physician and the physician and/or nurse with the Nuclear Medicine Department about their pregnancy. Are you pregnant (or suspect you may be)? You must also inform staff if there is a possibility that you may be pregnant. Women who are breastfeeding must also notify our staff.

• Non-urgent tests may be postponed and may possibly be performed without radiation. In certain cases, a test that uses a mildly radioactive tracer may still be the indicated choice.

Tests that utilise X-rays or mildly radioactive tracers may be used in children, as long as the medical importance of such tests is greater than possible risks. Children are far more sensitive to the effects of radiation than adults. Your physician will first consider techniques that do not use radiation. The unborn baby or babies are very sensitive to radioactive exposure. It is imperative to inform us in advance if you are (potentially) pregnant or if you are breastfeeding.

If you must have a test performed with Nuclear Medicine, we ask that you not have young children accompany you to the test.

Yes. An ultrasound or an MRI scan does not use X-rays. It is not, however, possible to always use this technique for every medical problem. For this reason, it may be that using these techniques does not offer a solution for your condition and medical question.

After the mildly radioactive tracer has been administered, there is a very low amount of radiation around the patient. If it is necessary to limit contact with others the day of the test, the staff member with our department will inform you of this.

For tests involving the skeleton, the heart, blood flow in the brain or white blood cell scans, we recommend that adult patients avoid unnecessary long or close contact with pregnant women and children younger than 6 years old for twelve hours after the injection. The amount of radioactive tracer we use for children is so low that there are no restrictions for contact afterwards.

The majority of mildly radioactive tracers is excreted in urine. Therefore, we recommend that the patient drink plenty of fluids and empty the bladder regularly on the day of the test. We ask that you sit down on the toilet seat to urinate and flush the toilet with the lid closed. We also ask that you wash your hands.

If you have any other questions, do not hesitate to ask our staff with the Nuclear Medicine Department.