Tests to find gestational trophoblastic disease
If you have symptoms, a doctor may use several tests to see if you have gestational trophoblastic disease.
Internal (pelvic) examination
An internal (pelvic) examination is usually the first of these tests. The doctor will feel for any lumps or strange feeling in the shape or size of the uterus.
The doctor may then do an ultrasound scan, a test that uses sound waves to find tumours. In this procedure, high-energy sound waves are bounced off internal tissues or organs to make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram.
A blood test will also be done to look for high levels of a hormone called human chorionic gonadotrophin (hCG), which is present during normal pregnancy. If a woman is not pregnant and hCG is in the blood, it can be a sign of gestational trophoblastic disease.
Once gestational trophoblastic disease has been found, more tests will be done to find out if it has spread from inside the uterus to other parts of the body.
This is called staging. The results will help you and your doctor decide on the best treatment for you.
You may have one or more of the following tests:
- Blood tests. You may have blood tests to assess your general health and to help make treatment decisions.
- Chest X-ray. You may have a chest X-ray to check that your lungs and heart are healthy.
- CT, MRI and PET scans. Computed tomography (CT) or magnetic resonance imaging (MRI) scans allow doctors to see pictures of the organs and other structures (including tumours) in your body. They are usually done at a hospital or radiology clinic.For a CT scan, you will be asked not to eat or drink anything before the scan, except for a liquid dye. The dye makes your organs appear white on the scans, so anything unusual will show more clearly. You will be asked to lie on a table while the scanner, which is large and round like a doughnut, moves around you.
An MRI scan uses a powerful magnet linked to a computer to take detailed pictures of areas inside the body. The pictures are taken while you lie on a table that slides into a metal cylinder.
Like a CT scan, an MRI scan is painless. However, some people find that lying in the MRI scan cylinder is noisy and claustrophobic. You can usually take someone into the room with you for company. If you feel uncomfortable, let your doctor or nurse know. They can give you medication to make you feel more relaxed.
You might also have a positron emission tomography (PET) scan. In this test, you will be injected with glucose solution containing a small amount of radioactive material. The PET scan detects increased quantities of radioactive glucose in areas of the body where there are cancer cells, because cancer cells cannot eliminate this glucose in the way that normal cells do.
These scans usually take less than a few hours, and most people are able to go home as soon as their scan is over.
People who are allergic to iodine may also be allergic to the dye used in a CT or MRI scan. If you think you are allergic, tell your doctor before the scan.