Neuroendocrine Tumor Diagnostic Tests

Neuroendocrine tumor diagnostic tests - Doctors use many tests to find or diagnose a neuroendocrine tumor (NET). They also do tests to find out if cancer has spread to other parts of the body from where it started. If this happens, it's called metastasis. For example, imaging tests can show if cancer has spread. Imaging tests show images of the inside of the body. Doctors can also do tests to find out which treatment is the most successful.

For most types of tumors, a biopsy is the only sure way for doctors to find out if an area of the body has a tumor. In a biopsy, the doctor takes a small sample of tissue to be tested in the laboratory. If a biopsy is not possible, your doctor may suggest other tests that will help with the diagnosis.

Depending on size and location, neuroendocrine tumors (NET) can be difficult to detect through standard imaging tests and may remain unidentified for long periods of time. At Penn Medicine's Abramson Cancer Center, we offer advanced diagnostic testing and sophisticated imaging procedures to accurately diagnose NET.

Tests for the diagnosis of NET include: biochemical tests, Metaiodobenzylguanidine Scanning (MIBG Scan), positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT).

This section explains the options for diagnosing NET. Not all of the tests listed below will be used for everyone. Your doctor may consider these factors when choosing a diagnostic test: Type of NET suspicion, signs and symptoms, age and general health status, as well as the results of previous medical examinations.

Neuroendocrine Tumor Diagnostic Tests

Most of the NET is found unexpectedly when people do x-rays or medical procedures performed for reasons that have nothing to do with the tumor. If the doctor suspects NET, he will request a complete medical and family history and undergo a full physical examination. Neuroendocrine tumor diagnostic tests - In addition, the following tests can be used to diagnose NET:

1. Blood/urine test. Your doctor may need a sample of your blood and urine to check hormone levels and other abnormal substances. The urine test checks the amount of 5-HIAA, a serotonin-breaking product produced by several .NET. Measurement of serotonin levels in the blood can also be performed, but this is less reliable due to fluctuations. Blood tests are sometimes performed to measure chromogranin A, a protein produced by tumor cells after diagnosis, to verify the tumor's response to treatment. Chromogranin A is not part of diagnostic tests.

2. Endoscopy. An endoscope allows the doctor to see the inside of the body with a thin, illuminated and flexible tube called an endoscope. There are many types of endoscopy, including upper digestive endoscopy to examine the esophagus and stomach, and colonoscopy to examine the rectum and large intestine. The person can be sedated when the tube is gently inserted into the body. Sedation is the administration of medications to get more relaxed, calm or sleepy. If an abnormality is found, a biopsy will be performed.

3. X-rays. An x-ray is a way to create images of structures in the body using a small amount of radiation. Neuroendocrine tumor diagnostic tests - Sometimes the NET may not appear on the x-ray because of its size or location; therefore, doctors may also recommend other types of scanning. If the doctor suspects the NET digestive tract, an x-ray of the barium can be done. A person swallows a barium-containing liquid lining the lining of the esophagus, stomach, and intestine. Then a series of X-rays are done.

4. Magnetic Resonance Imaging (MRI). An MRI uses a magnetic field, not x-rays, to produce detailed images of the body. Magnetic resonance imaging can be used to measure tumor size. Special dyes called contrast media are provided before scanning to make images sharper. This dye can be injected into the patient's blood vessels or administered as a tablet or liquid to swallow.

5. OctreoScan. This imaging test uses octreotide associated with Indian-111 as a tracker. This procedure is useful for identifying where the NET has spread, especially if it has spread to the liver.

6. Biopsy. A biopsy is the removal of a small amount of tissue to be examined under a microscope and is necessary for the diagnosis of NET. A pathologist analyzes the sample taken during the biopsy. Pathologists are physicians specialized in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose diseases. It should be noted that tumors with suspected pheochromocytoma should not be biopsied unless absolutely necessary to confirm the diagnosis. A biopsy of this tumor can be fatal.

7. Molecular testing of tumors. Your doctor may recommend running laboratory tests on tumors to identify genes, proteins, and other factors unique to tumors. The results of this test can help determine your treatment options. This test is less useful in the NET than in other cancers.

8. Ultrasound. An ultrasound uses sound waves to create images of internal organs. Tumors produce different echoes of the sound waves of normal tissue. This means that when the waves are reflected back to the computer, creating images, doctors can find masses in the body. There are several types of ultrasound that are used to examine various parts of the body. In some cases, a biopsy may be done during the procedure.

9. Computed tomography (CT or CAT). A CT scan takes pictures of the inside of the body using an x-ray taken from different angles. The computer combines these images into detailed three-dimensional images that indicate abnormalities or tumors. Computed tomography can be used to measure tumor size. In addition, a CT scan is used to check if the tumor has spread to the liver. Occasionally, special dyes called contrast media are provided before scanning to provide better image details. This dye can be injected into the patient's blood vessels or administered as a tablet or liquid to swallow.

10. Image of nuclear drugs. During this test, a small amount of a radioactive drug, called a tracer, is injected into the patient's blood vessels. The body then scans to show where radioactivity formed in the body. There are several methods of imaging nuclear drugs available in the NET, including OctreoScan and 2 types of PET-CT scans.