To help make the diagnosis, you will probably have a number of tests. Even after a diagnosis is made, further tests may be needed to find out about the size and position of the cancer, and whether it has spread to other parts of the body. The results will help you and your doctor to decide on the best treatment for you.
Although tests are useful, no one test can tell the whole story. For example, even the most modern scans cannot always pick up tiny areas of cancer. Occasionally, other medical conditions can cause similar results, making it difficult to decide what is and is not cancer. Doctors often have to piece together information from different tests and examinations, along with your symptoms and medical history, and then put all this information in context.
Usually, only tests that give the most helpful information about the illness are used. The following tests are most often used to diagnose cancer of the pancreas:
Blood tests
Many cancers of the pancreas produce a substance called CA 19-9, which can be measured in the blood. CA 19-9 is known as a tumour marker. Measuring the level of CA 19-9 in the blood can help in diagnosing a cancer of the pancreas, and also in seeing how it responds to treatment. This test needs to be used alongside other tests, such as scans, as it is not completely specific.
CT (computerised tomography) scan
This is a series of x-rays which builds up a three-dimensional picture of the inside of the body. The scan is painless but takes longer than an ordinary x-ray (10–30 minutes). CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with . You will be asked not to eat or drink for at least four hours before the scan.
The scan is painless but it will mean lying still for about 10–30 minutes
Special liquids are often used to allow particular areas of the body to be seen more clearly on the scan. They may be given as a drink or an injection, or both. If you are allergic to iodine or have asthma, it is important to tell your doctor and the person doing this test before having the injection or drink. It is usually still possible to have the injection, as long as you have treatment with a steroid drug such as prednisolone on the day before and the day of the injection.
CT scans can be used to guide a biopsy, in which tissue is taken for examination under a microscope. You will be told if that is planned. You will probably be able to go home as soon as the scan is over.
Ultrasound scan
Ultrasound uses sound waves to look at internal organs, such as the pancreas and the liver. You will usually be asked not to eat or drink anything for at least six hours before the test.
Once you are lying comfortably on your back, a gel is spread on to the area to be scanned. A small device that produces sound waves is passed over the area. The sound waves are then converted into a picture by a computer. This test only takes a few minutes.
As with CT scans, an ultrasound can be used to guide a biopsy, in which tissue is taken for examination under a microscope.
MRI (magnetic resonance imaging) scan
This test is similar to a CT scan but uses a magnetic field instead of x-rays to build up cross-sectional pictures of your body. Some people are given an injection of dye into a vein in the arm to improve the image. During the test, you will be asked to lie very still on a couch inside a long chamber, for up to an hour. This can be unpleasant if you don’t like enclosed spaces; if so, you should mention this to the radiographer. The MRI scanning process is also very noisy, but you will be given earplugs or headphones to wear. You can usually take someone with you into the room to keep you company.
The scanner has a very powerful magnet inside it, so before entering the room you should remove any metal belongings. People who have heart monitors, pacemakers, or some types of surgical clips, cannot have an MRI because of the magnetic fields.
ERCP
ERCP (endoscopic retrograde cholangio-pancreatography) enables the doctor to take an x-ray picture of the pancreatic duct and the bile duct. The bile duct can be unblocked during this procedure if necessary.
Before the test, you will be asked not to eat or drink anything for about six hours so that the stomach and small bowel (duodenum) are empty. You will be given an injection to help you to relax and some local anaesthetic will be sprayed on to the back of your throat. The doctor will then pass a thin, flexible tube, known as an endoscope, into your mouth, through your stomach and into the duodenum just beyond it. Looking down the endoscope, the doctor can find the opening where the bile duct and the duct of the pancreas drain into the duodenum. A dye that can be seen on x-ray is then injected into these ducts to show up any abnormalities or any blockage of the duct.
You will usually be given an injection of antibiotics before the test, to prevent any infection.
EUS
A newer test, that is sometimes used instead of an ERCP, is an endoscopic ultrasound (EUS). This is a very similar procedure to an ERCP, but involves an ultrasound probe being passed down the endoscope, to take an ultrasound scan of the pancreas and surrounding organs.
Biopsy
If your doctor strongly suspects that you have cancer of the pancreas, the surest way of making a diagnosis is to remove some cells, or a small piece of tissue, from the tumour, to look at under a microscope. This is called a biopsy. In some people, where the tumour is very difficult to reach, it is not possible to do this.
A biopsy can be taken in a number of ways. It may be possible to insert a needle through the skin of the abdomen to take a small piece of tissue, using an ultrasound or CT scan for guidance. You will be given an injection of local anaesthetic to numb the area so that you feel little or no pain from the insertion of the needle.
Another way is to take some cells during an ERCP. The doctor may be able to remove cells from the tumour by taking samples of the area through the endoscope, using a special type of brush.
Laparoscopy
This test involves a small operation done under a general anaesthetic and will mean a short stay in hospital. It allows the doctor to look at the area of the pancreas and see whether an operation will be possible.
The doctor makes a small cut (about 2cm) in the skin and muscle near the navel and carefully inserts a thin, fibre-optic tube (laparoscope) into your abdomen. The doctor can then examine the area and take a sample of tissue (biopsy) for examination under the microscope.
Sometimes laparoscopy is carried out whilst using ultrasound, to make sure that the laparoscope is in the right place and can examine any abnormal areas.
If the above tests do not give a definite diagnosis, an operation to look inside the abdomen (called a laparotomy) may be done under a general anaesthetic. A biopsy can be taken during the laparotomy. If surgery is needed to remove the cancer, this is sometimes done at the same time.
ERCP, biopsy and laparoscopy can cause problems for some people. It is advisable to discuss any possible risks with your specialist before having any of these procedures.
Via: http://www.cancerbackup.org.uk
No comments:
Post a Comment