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Radioactive scans

These are octreotide scans (or Octreoscans) and MIBG scans. You have an injection of a low dose radioactive substance, which can show up on a scan.

An octreotide scan is also called somatostatin receptor scintigraphy.

What they are

Octreotide and MIBG are substances that some carcinoid cells take up (absorb). Doctors can attach a radioactive substance to octreotide or MIBG, which a special camera (called a gamma camera) can pick up. The radioactive substance is also called a radioactive tracer or radionuclide.

The scans show up areas where radioactivity collects in the body. This can show where a carcinoid tumour is and if it has spread. 

The amount of radiation is very small. You have the scan in the nuclear medicine department at the hospital. You usually have scans on 2 days.

Preparing for your scan

Check your appointment letter to see how to prepare for your scan. You may need to stop taking certain medicines beforehand.

If you are going to have an MIBG scan, you take some iodine medicine. This stops your thyroid gland from absorbing the radioactive tracer. You take it the day before the scan, and for the next 1 or 2 days. Your appointment letter gives more information about this.

The evening before your appointment, you take a gentle laxative. This helps to clear your bowel so the doctors can get clearer pictures. You can eat and drink as normal.

Contact the department as soon as you can before the scan if you are, or think you might be, pregnant. Also, let them know if you are breastfeeding, or are the main carer of a baby or young child.

Before your scan

When you arrive at the department, a specialist nurse or technologist gives you the radioactive tracer. They inject it through a small tube (cannula) in the back of your hand or in your arm.

It takes about 4 hours for the tracer to travel through your bloodstream and collect in areas of your body. You can usually leave the hospital during this time. You need to drink plenty and go to the toilet regularly. This is to get rid of any excess tracer, and helps to give clearer pictures.

Your technologist or nurse will give you a time to be back for the scan.

Having the scan

Your technologist will ask you to go to the toilet to empty your bladder before the scan.

You then lie on the scanning bed. There are special cameras above you and under you. They move along the length of your body taking pictures. You need to lie as still as possible during the scan. It takes about 30 minutes.

You are then able to go home. You go back to the hospital the next day for another scan. This can last up to 3 hours. You have the chance to move around or go to the toilet during this time.

Sometimes you need to go back to the hospital for a third day to have more scans.

After your scan

You can go home after the scan. You need to drink plenty over the next few days. This is to help flush out the radioactive tracer from your body.

The radioactive tracer gives off small levels of radiation that goes away quickly. But for up to a few days after having the injection you should avoid long periods of close contact with pregnant women, babies and young children. Your nurse or technologist will give you more information about this.

If you’re travelling abroad a short time after your scan, it may be a good idea to take your appointment letter with you to show that you’ve had a scan. Most airports have sensitive radiation monitors that may pick up the trace of radiation from your test.

Possible risks

There is a small risk from the radiation. It can increase the risk of cancer in the future by a very small amount. It is a low dose of radiation and your doctor makes sure the benefits of having the test outweigh this small risk. Talk to your doctor or nurse if you are worried about this.

There is a risk of an allergic reaction to the radioactive injection. This is rare, and usually a mild reaction. Tell your nurse or technologist if you feel unwell at all after having the injection.

Getting your results

You should get your results within 1 or 2 weeks. The doctor who arranged the test will give them to you. Contact them if you haven't heard anything after a couple of weeks.

Waiting for results can make you anxious. You might have contact details for a specialist nurse who can give you information and support. It may help to talk to a close friend or relative about how you feel.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.
Last reviewed: 
24 May 2016
  • Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)
    JK Ramage and others
    Gut,  2012. Volume 61, Issue 1

  • Pulmonary neuroendocrine (carcinoid) tumors: European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids
    ME Caplin and others
    Annals of Oncology, 2015. Volume 26, Issue 8

  • Cancer: Principles and Practice of Oncology (10th edition)
    VT DeVita , TS Lawrence, SA Rosenberg
    Lippincott, Williams and Wilkins, 2015

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