Tests for Bone Mets
Sometimes bone metastasis are found before symptoms show up. In some cancers, where bone metastasis is common, tests might be done to make sure the cancer has not spread to your bones before a treatment plan is made.
When you have symptoms of bone metastasis, these are some of the tests that can be used:
- Bone scan. A bone scan can often find bone metastasis earlier than an X-ray can. The scan looks at your whole skeleton, so all the bones in your body can be checked for cancer. In a bone scan, a mildly radioactive tracer is put into your blood through a vein. The tracer is attracted to diseased bone cells all over your body. This helps diseased bone show up more clearly on the scan.
- CT scan. This test shows detailed images of any part of the body, including the bones. It’s more detailed than a regular X-ray. It uses a combination of X-rays and computer technology to make cross-sectional images of the inside of the body. These images are combined into detailed pictures to show if cancer has spread to the bones.
- MRI. An MRI scan uses radio waves and strong magnets, instead of X-rays, to make pictures of bones and tissues. MRI makes cross-sectional images of the inside of the body. It’s very useful in looking at the spine and spinal cord, as well as joints. Often, an MRI helps to get a better look at the outline of a bone mass seen on an X-ray.
- X-rays. An X-ray can show where in the skeleton the cancer has spread. X-rays also show the general size and shape of the tumor or tumors.
- PET scan. This imaging test uses a type of sugar that’s radioactive. This sugar is put into your blood. Cancer cells absorb large amounts of the sugar, compared to normal cells. After the injection, you lie on a table in a PET scanner, while your whole body is imaged. A special camera takes pictures of the radioactive areas found in your body. A PET scan is not very detailed, but can sometimes find tumors too small to be seen on other tests. If an abnormal area is seen, your doctor will likely order another test for more information. This may be a CT scan or MRI. New machines combine PET and CT scans for more detailed images all at once.
- Lab tests. Bone metastasis can cause many substances to be released into the blood. Blood tests can be done to see if there are higher amounts than normal. Two such substances are calcium and an enzyme called alkaline phosphatase. Blood tests for these substances can help diagnose bone metastasis. These levels can also be used to measure the levels of these chemicals over time to check your response to treatment. But remember, higher levels of these substances can be a sign of other health problems, too, not just metastasis.
- Biopsy. Your healthcare provider may suggest a bone biopsy to be sure a change is bone metastasis. A small piece of bone is removed and tested for cancer cells. This is often done when imaging tests and blood tests suggest, but don’t confirm, you have metastasis.