What is an Octreotide scan?
An octreotide scan (also called a somatostatin receptor scintigraphy) is a test used to check the body for neuroendocrine tumor cells. This test is done in a Nuclear Medicine department, which is a type of radiology that uses radioactive materials to diagnose or treat diseases.
Neuroendocrine tumors start from neuroendocrine cells, which are found throughout the body. As a result, neuroendocrine tumors can be found in many areas of the body, including the brain, thyroid, lungs, and GI tract. Many neuroendocrine tumors have receptors on their surface for a hormone called somatostatin. When an octreotide scan is done, these receptors are targeted so that neuroendocrine tumor cells can be seen on the scan.
Octreotide scans are highly specialized and need radioactive material to be done. Not every cancer center can do these scans.
What is this test used for?
This test is used to look for neuroendocrine cells throughout the body.
This scan may be used to see the primary neuroendocrine tumor during initial (diagnostic) testing. It may also be done at other times to check for tumor cells that have spread (metastasized).
How is this test done?
- An IV is placed.
- An injection of octreotide with radioactive material attached to it (called "radiolabeled"), is given. The amount of radiation used is very small.
- Octreotide is a drug that is a lot like the hormone somatostatin. Cells with somatostatin receptors on their surface will attract and attach to the radiolabeled octreotide.
- The radioactive material puts out a low dose of radiation that can be seen with a special scanner (similar to a CT scan).
- About 4 hours after the injection, you will undergo this scan to look for cells that have taken up the octreotide.
- You lie flat, with a camera taking pictures above and below you. The scan checks the whole body. The scan can take an hour or longer.
You will need more than one scan. The first set of scans is done on the day of the injection. A CT Scan is done to create a 3D image of your body. You will return for more scans depending on your provider’s directions.
The scanner's computer creates a figure of your body on the screen. Any areas with increased octreotide uptake show up as a bright spot on the picture.
How do I prepare for an octreotide scan?
If you are taking octreotide or somatostatin, you may need to stop the medication before the scan. You should talk about this with your provider.
If you are pregnant or nursing a baby, you should tell your provider before the scan.
What is included in an octreotide scan report?
The images are processed by a computer and read by a nuclear medicine physician. A report is created.
The report states your name, date of birth, and indication (reason for the octreotide scan) at the top of the report. Radiology reports follow a standard outline, regardless of where the tests are done. Radiologists report both normal and abnormal findings in a standard way. It is important to talk about 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 made for other medical professionals, the words used can be hard to understand.
- Following the detailed results above, an “impression” generally follows. The impression is a summary of the findings, often given to answer the question asked by the ordering provider (the reason the scan was ordered in the first place).
If you have any questions about your octreotide scan or the results you should contact your provider.
Kapoor M, Kasi A. Octreotide Scan. [Updated 2021 Aug 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559330/
National Institute of Health: National Cancer Institute. Octreotide Scan. Retrieved from https://www.cancer.gov/publications/dictionaries/cancer-terms/def/octreotide-scan.