Ga-68 Dotatate Scan

What is a Ga-68 dotatate scan?

A Ga-68 dotatate scan is a test used to check your body for a type of cancer cell called neuroendocrine tumor (NET) cells. Neuroendocrine tumors come from neuroendocrine cells in the body. NETs can be found in many parts of the body, such as the brain, thyroid, lungs, and GI (gastrointestinal) tract.

The Ga-68 dotatate scan has taken the place of octreotide scans in most cancer centers because it can find more areas of NET. This scan is highly specialized and not every center can do this type of scan.

What is this test used for?

This test is used to look for NET cells throughout the body.

This scan may be used to diagnose your tumor. It may also be done to check how your treatment is working, and where or if tumor cells have spread (metastasized).

You will have this test done in the Nuclear Medicine department of your healthcare center. Nuclear medicine is a type of radiology that uses radioactive materials to diagnose or treat diseases.

How is this test done?

About 7 to 9 out of 10 NETs have receptors on their surface for a hormone called somatostatin. Octreotide is a protein that attaches to the somatostatin receptor. Ga-68 is a type of radiotracer – a radioactive material that is attached to octreotide for the Ga-68 dotatate scan. You will have an IV (intravenous, into a vein) placed. The Ga-68 dotatate “radioactive tracer” will be given through your IV. The amount of radiation used is very small.  With the octreotide attached to the radioactive Ga-68 dotatate, it enters the body and attaches to the somatostatin receptors on NET cells. A PET scan is then done to see the areas where the Ga-68 dotatate has been attached. The test takes about 2 hours.

The computer makes an image of your body on the screen. Any areas with a higher amount of Ga-68 will show up as a bright spot on the image. It is important to remember that the tracer goes through many areas of the body. This causes some areas to show up on the scan that are not always NET. It is important to review the report with your provider to understand it.

How do I get ready for a Ga-68 dotatate scan?

If you are taking octreotide or somatostatin, you may need to stop the medication before having the scan. You should talk about this with your provider. You do not need to fast (avoid eating) before the test. Drink plenty of water before the test. You should drink 1 liter of fluid during the 2 hours before the test. Keep drinking plenty of water for a few hours after the test to help wash the radiotracer out of your body.

If you are pregnant or nursing a baby, you should tell your provider before the scan.

How do I read the results of the scan report?

After the scan, the computer makes the images and they are read by a nuclear medicine doctor. A report is made with the results.

Radiology reports follow a standard outline, no matter where they are done. Radiologists report both normal and abnormal findings. For this reason, it is very important to go over the results with your provider.

• The first paragraph often has information about the scan (for example, how much radiolabeled octreotide was given, if the whole body was scanned, and so on).
• The middle paragraphs describe the findings, both normal and abnormal. Since reports are written for other medical professionals, the words used can be hard to understand.
• Following the detailed results above, an “impression” is often made. The impression is an overview of the findings. 

Talk about the results of your Ga-68 dotatate scan with your care team.