Ga-68 Dotatate Scan
What is a Ga-68 Dotatate scan?
A Ga-68 dotatate scan is a test used to check the body for the presence of neuroendocrine tumor cells. You will have this test done in the Nuclear Medicine department. Nuclear medicine is a type of radiology that uses radioactive materials to diagnose or treat diseases.
Neuroendocrine tumors (NET) come from neuroendocrine cells, which are found throughout the body. NETs can be found in many areas of the body, including the brain, thyroid, lungs, and GI tract. About 70-90% of 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 substance that is attached to octreotide for the Ga-68 dotatate scan.
Ga-68 dotatate / octreotide attaches to the somatostatin receptors on the NET cells. A PET scan can “see” the areas where the Ga-68 dotatate has attached. This allows your care team to clearly see where the NETs are in your body.
The Ga-68 dotatate scan has taken the place of the octreotide scan in most specialty centers because it can find more areas of NET. This scan is highly specialized and not every center has the ability to do this type of scan.
What is this test used for?
This test is used to look for the presence of NET cells throughout the body.
This scan may be used during your initial (diagnostic) testing to find the primary tumor or look at where the NET has spread. It may also be done at other times to check how the treatment is working or if tumor cells have spread, or metastasized.
How is this test performed?
You will have an IV placed and an injection of the Ga-68 dotatate “radioactive tracer” given. The amount of radiation used is very small.
Cells with somatostatin receptors on their surface will attract and attach to the Ga-68 dotatate. You will then have a PET scan, which can detect the radiation put off by the Ga-68 dotatate. The test takes about 2 hours.
The scanner's computer creates a figure of the patient 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 normally goes through many areas of the body. This causes some areas to appear on the scan that are not necessarily NET. It is important to review the report with your provider to understand it.
How do I prepare for a Ga-68 dotatate scan?
If you are taking octreotide or somatostatin, you may need to stop the medication prior to the scan. You should discuss this with your provider as it is not always necessary. You do not need to fast before the test. Drink plenty of water before the test. It is recommended to drink 1 liter of fluid during the 2 hours before the test. Continue drinking plenty of water for a few hours following the test to help wash the radiotracer out of your body.
If you are pregnant or nursing a baby, you should notify your provider prior to the scan.
How do I interpret the results of the scan report?
Following the scan, the images are processed by a computer and read by a nuclear medicine physician. A report is created with the results.
Radiology reports follow a standard outline, regardless of where they are done. Radiologists report both normal and abnormal findings. For this reason, it is very important to discuss the results with your provider.
- The first paragraph often includes the technical information about the scan (for example, how much radiolabeled octreotide was given, whether the whole body was scanned, etc).
- The middle paragraphs describe the findings, both normal and abnormal. Because reports are written for other medical professionals, the words used can be hard to understand.
- Following the detailed results above, an “impression” often follows. The impression is a summary of the findings. You should discuss the results with your care provider.
NETWise Podcast. Episode 2: Imaging, Testing, and Building a Care Team. https://netrf.org/podcast/episode-2-imaging-testing-and-building-a-care-team/
Neuroendocrine Tumor Research Foundation. Ga-68 Dotatate PET?CT Scan for Neuroendocrine Tumors. https://netrf.org/2018/11/13/gallium-68-scan-for-neuroendocrine-tumors/
Raj, N., & Reidy-Lagunes, D. (2018). The Role of 68Ga-DOTATATE PET/CT in Well Differentiated Neuroendocrine Tumors: A Case-Based Approach Illustrates Potential Benefits and Challenges. Pancreas, 47(1), 1.
Sanli, Y., Garg, I., Kandathil, A., Kendi, T., Zanetti, M. J. B., Kuyumcu, S., & Subramaniam, R. M. (2018). Neuroendocrine tumor diagnosis and management: 68Ga-DOTATATE PET/CT. American Journal of Roentgenology, 211(2), 267-277.
Subramaniam, R. M., Bradshaw, M. L., Lewis, K., Pinho, D., Shah, C., & Walker, R. C. (2018). ACR practice parameter for the performance of gallium-68 DOTATATE PET/CT for neuroendocrine tumors. Clinical nuclear medicine, 43(12), 899-908.