Tests That Help Evaluate Primary Bone Cancer
Once your doctor knows you have primary bone cancer, he or she may request more tests to learn more about its type and its specific location. When your doctor suspects the tumor is cancer, he or she will usually order these tests before a biopsy. You will probably have more than one of these tests.
Computed tomography (CT scan)
A CT scan of the tumor, lungs, or both can help tell if the primary bone cancer has spread. CT scans can also help find out what stage the cancer is in. The CT scan uses special X-rays that give detailed pictures of the inside of your body. During a CT scan, a doughnut-shaped X-ray machine scans the area of your body where your doctor suspects there is cancer.
A CT scan is painless and noninvasive. The technician may ask you to hold your breath one or more times during the scan. You may first get an intravenous (IV) injection of dye. The dye helps outline parts of your body so that they show up better on the CT scan. You may be asked to drink a contrast agent to improve the pictures of your intestine.
To have the test, you lie still on a table as it slides through the center of the scanner, which takes many pictures of your body from many angles. A computer combines these pictures to create a cross-section of your body.
Before having the test, tell the technician if you are allergic to iodine or shellfish. Also, let the technician know if you are a diabetic taking Glucophage (metformin). You must stop taking this medicine 24 hours before the scan. You may also want to mention if you are claustrophobic.
Magnetic resonance imaging (MRI)
An MRI is the best test for outlining the shape of the tumor. Your doctor may recommend this test instead of or in addition to a CT scan. Instead of X-rays, MRIs use radio waves and magnets to make the image. The energy from the radio waves creates patterns formed by different types of tissue and diseases. This makes very detailed pictures of the inside of your body. The doctor may inject a contrast dye into your veins to see the tumor more clearly.
For this test, you lie still on a table as it passes through a tube-like scanner. Then, the scanner directs a continuous beam of radio waves at the area being examined. A computer uses data from the radio waves to create pictures of the inside of your body. You may need more than one set of images. This test is painless and noninvasive, but it may last an hour or more. Ask for earplugs since there is a loud thumping noise during the scan when images are taken. If you are claustrophobic, you may want a sedative before having this test.
Bone scans show areas of cellular activity in bones, which can sometimes indicate cancer. Bone scans can often show where the cancer has spread and can identify metastases, or the spread of cancer, earlier than an X-ray. Because bone scans do not create detailed images, other tests, such as X-rays of the bone, may be needed if any abnormal spots are seen.
A bone scan is a kind of radionuclide scanning. For this test, the doctor or technician injects you with a small amount of radioactive material. It travels through your bloodstream and collects in areas of abnormal bone growth. You need to wait about two hours between the injection and the bone scan. It’s recommended that you drink fluids during those two hours to help circulate the dye. After two hours pass, you lie on a table for about 30 minutes while a machine scans your body for the places the substance has collected, sometimes called hot spots. The amount of radioactive material used for this test is small. It shouldn’t be harmful to you or your family.
Positron emission tomography (PET or PET scan)
PET looks for cancer throughout your body. A PET scan can be more helpful than several different X-rays because it scans your whole body. It can sometimes tell if a tumor is cancerous or benign. PET scans do not provide detailed images, but they are often combined with CT scans to see exactly where an area of abnormal activity is.
You will not be able to eat or drink anything for six hours before the scan. A small amount of sugar (called glucose) that contains a radioactive tracer will be put into your arm through an IV. About one hour after you get the radioactive tracer, you’ll get the PET scan.
A special camera looks for the radioactivity in the tracer. Cancer cells absorb higher amounts of the radioactive sugar than normal cells. You will lie on a table as the scan machine moves over your body. The scan takes about one hour.