Nuclear medicine scan
This is also known as a radionuclide scan. It involves having a chemical put into your body that can be picked up by a scanner, similar to having a contrast dye for a CT or MRI scan. But in this case, the chemical – known as a tracer or radionuclide – is radioactive. The tracer gives off a type of radioactivity called gamma rays.
Certain tumours and areas of your body absorb specific chemicals such as gallium, iodine, MIGB and octreotide. These are made mildly radioactive and then put into your bloodstream. Because the tumours and/or the area of your body absorb the substance which is giving off gamma rays, they show up on the scan.
For example, if you have radioactive iodine injected into a vein, the tissues of your thyroid gland quickly absorb it. So, it is used to take images of your thyroid gland.
The dose of radioactivity you get is very low (about the same as you get from an x-ray). Almost all of it leaves your body within a week.
What is it used for?
It enables us to a good idea of where the tumours are, their size and their structure. We may use this test to find where the cancer started (the primary tumour), or to check for any spread of the disease (secondaries or metastases).
Types of nuclear scan include:
- bone scan
- DMSA kidney scan
- gallium scan
- lung permeability scan
- MIBG scan
- thyroid scan.
Do I need to prepare?
If you are pregnant, or think you may be pregnant, please tell us before your scan. Even small amounts of radiation can harm unborn babies.
You can have the scan if you are breastfeeding, but please contact us for advice before you come in for your test.
If you have diabetes, do not have any food or drink that contains caffeine in the 24 hours before your test. Otherwise you can eat and drink as normal.
What happens during the procedure?
You usually need to come in several hours before your scan to have the tracer. It is injected into your bloodstream or you may be asked to swallow a small tablet or breathe in a spray that contains it.
You will have up to three scans: one on the day the tracer is put in your body and two more over the next two – three days.
You will be asked to lie or sit on a couch and stay still while a special camera takes pictures of the tracer in your body. Each scan takes up to about an hour and a half. You will be able to go home between scans.