Imaging tests diagnose and monitor NETs. Since NETs can sometimes be hard to “see,” your doctor may use different scans than those used for other types of cancer.
Computed tomography, or CT, uses a highly specialized x-ray machine and computers to create multiple cross-sectional images of the body. A CT scan can generate images of different body tissues as well as help detect tumors. A dye may be injected into a vein or swallowed to help the organs or tissues show up on the scans more clearly.
Magnetic resonance imaging, or MRI, uses radio waves, a powerful magnetic field, and a computer to generate detailed (i.e., two- or three-dimensional) images of the body. These images are useful in contrasting different types of tissue as well as detecting abnormal growths in the body like tumors. MRI can be useful for locating and measuring metastases.
Positron emission tomography (PET) uses radioactive material and a special scanning device to detect NETs.
Gallium 68 (Ga-68) or Copper-64 (Cu-64) scan
This imaging test uses a radioactive tracer called Gallium-68 (Ga-68) or Copper-64 (Cu64) to bind to a tumor’s somatostatin receptors. Patients undergo a PET scan after an injection of the tracer (Ga-68 or Cu64) . The images from the scan can show NETs located anywhere in the body if the tumors have receptors for the tracer.
Octreoscan
Octreoscan uses a radioactive substance that can bind to and illuminate any somatostatin receptors in a tumor (not all tumors have somatostatin receptors). In this test, a tiny amount of radioactive octreotide is injected into a vein so it can travel through the bloodstream.
Octreotide then attaches to the tumors and a special camera that detects radioactivity shows the sites in the body in which the tumors are located. In many centers, the Gallium or Copper-64 scan is preferred to the octreoscan.
FDG (fluorodeoxyglucose) scan
An FDG-PET can find fast-growing neuroendocrine cancer cells in many aggressive tumors. A small amount of FDG, a type of radioactive sugar, is injected into a vein. The PET scanner rotates around the body and constructs a picture of where the body is using the sugar. Cancer cells appear brighter in the picture because they are more active and take up more sugar than healthy cells. FDG is commonly used to detect tumors that are high grade and/or poorly differentiated.
MIBG scan
An MIBG scan is used to find pheochromocytoma and paraganglioma. A tiny amount of a radioactive substance called MIBG is injected into a vein so it can travel through the bloodstream. The scan can then detect NET cells that take up MIBG. These scans may be taken over a period of 1-3 days.
Endoscopy is a medical procedure that uses an endoscope to view the lining of multiple organs in the body. An endoscope is a flexible or rigid tube with imaging capabilities that can enable small surgical procedures.
Endoscopy can be used to visualize tumors in the lungs and GI tract, small/large intestine, and rectum. Sometimes, an ultrasound probe is put on the end of the endoscope to perform what is called an endoscopic ultrasound, which can be particularly useful for looking at adjacent organs like the pancreas.
Colonoscopy
Colonoscopy is a procedure to look inside the rectum and colon for abnormal tissue or cancer. A colonoscope is a thin, tube-like instrument with a light and a lens to inspect the rectum and colon. The instrument may also have a tool to remove polyps or tissue samples, which are then analyzed under a microscope for signs of cancer.
Upper GI Endoscopy
An upper GI endoscopy or esophagogastroduodenoscopy (EGD) is a procedure doctors use to diagnose and treat problems in the upper GI tract, which includes your esophagus (food pipe), stomach, and the first part of your small intestine (the duodenum).
Bronchoscopy
Bronchoscopy is a procedure to look inside the trachea and the large airways in the lung for abnormal areas. A bronchoscope is a thin, tube-like instrument with a light and a lens that is inserted through the nose or mouth and down into the trachea and lungs. The bronchoscope may also have a tool to remove tissue samples, which are then checked under a microscope for signs of cancer.
Testing can help your doctor understand the specifics of your tumor and develop a treatment plan for your neuroendocrine cancer.