Tests for Bone Cancer

Bone x-ray

An x-ray is often the first test done if doctors suspect a bone tumor. They can often recognize a tumor based on x-rays of the bone. Tumors might have “ragged” edges instead of looking solid on an x-ray, or they might look like a hole in the bone. Sometimes doctors can see a tumor that might extend into nearby tissues, such as muscle or fat.

Your health care team might strongly suspect an abnormal area is bone cancer by the way it appears on an x-ray, but they usually need a biopsy to know for sure.

Chest x-ray

X-rays can also be used to see if a cancer has spread to your lungs. An x-ray can find larger tumors, but it isn’t as good as a CT scan for spotting smaller tumors. If you get a CT scan of your chest, you might not need an x-ray.

An MRI creates detailed images of the soft tissues inside your body. This is done using radio waves and strong magnets instead of x-rays, so there is no radiation. A contrast material called gadolinium may be injected into your vein before the scan to see details better. An MRI scan usually shows better details than a CT scan (described below).

MRI to look at an abnormal area: If doctors see an abnormal area of bone on an x-ray, they often use an MRI to get a more detailed look. MRIs can usually show if the abnormal area is likely to be a tumor, an infection, or some type of bone damage from another cause.

MRI to see the extent of a tumor: MRIs can help doctors see how much cancer is in your body (the extent of a tumor). This type of imaging shows the marrow inside bones and the soft tissues around the tumor, including nearby blood vessels and nerves.

MRIs can also show any small bone tumors several inches away from the main tumor, called skip metastases. Knowing the extent of the tumor is very important when planning surgery.

A CT scan combines many x-ray pictures to make detailed cross-sectional images of the inside of your body. Before the test, you might get an IV (intravenous) injection of a contrast dye to help get a clearer picture.

• If a bone x-ray shows a tumor, CT scans are sometimes used to see if the tumor has grown into nearby muscle, fat, or tendons, although MRI is often better for this.
• CT scans are often done to look for possible cancer spread in other parts of the body, such as the lungs, liver, or other organs.

CT-guided needle biopsy: CT scans can also be used to guide a biopsy needle into a tumor. For this test, you stay on the CT scanning table while the doctor moves a biopsy needle toward the tumor. CT scans are repeated until the tip of the needle is within the mass.

PET scans can help show the spread of bone cancer to your lungs, other bones, or other parts of your body. This type of imaging can be done again during treatment to see how well it is working.

For a PET scan, a radioactive sugar is injected into your blood. The amount of radioactivity is very low and will pass out of your body within a day or so. Because cancer cells grow quickly, they absorb large amounts of the sugar. These areas are visible on the PET scan.

About an hour after the injection, you are moved onto a table in the PET scanner. You lie on the table for about 30 minutes while a special camera creates a picture of areas of radioactivity in your body. The picture is not detailed like a CT or MRI scan, but it provides useful information about your whole body.

PET/CT scan: Some machines can do a PET and CT scan at the same time (PET/CT scan). This lets the doctor compare areas of higher radioactivity on the PET scan with the more detailed image of that area on the CT scan.

A bone scan can show if a cancer has spread to other bones. It is often part of the workup for people with bone cancer. This test is useful because it can show the entire skeleton at once. A PET scan, described above, often provides similar information, so a bone scan might not be needed if you get a PET scan.

For this test, a small amount of low-level radioactive material called technetium-99 is injected into your blood and travels to your bones. A special camera that can detect the radioactivity then creates a picture of your skeleton.

Areas of active bone changes attract the radioactivity and appear as “hot spots” on the skeleton. Hot spots may suggest areas of cancer, but other bone diseases can also cause the same pattern. To make an accurate diagnosis, other tests such as plain x-rays, MRI scans, or even a biopsy might be needed.

The amount of radioactivity used in this test is very low, and the material passes out of the body within a day or so.

For this type of biopsy, a thin, hollow needle is inserted through your skin and into the tumor to remove a small sample.

This is usually done with local anesthesia, where numbing medicine is injected into the skin and other tissues over the biopsy site. In this case, you will stay awake for the biopsy but should feel little or no pain. In some situations, you might need medicine to make you sleepy (sedation) or to put you into a deep sleep (general anesthesia).

If the suspicious area is near the surface of the body, the doctor often can aim the needle by feeling the area. If the tumor can’t be felt because it’s too deep, the doctor can guide the needle into the tumor using an imaging test such as ultrasound or CT scan.

This type of biopsy is not usually used for diagnosing a bone tumor. However, it can be used to confirm spread of cancer to the bone (metastasis) or a recurrent bone cancer (cancer that comes back after treatment).

This kind of biopsy doesn’t show the structure of the bone and often collects a very small amount of cells, too small to diagnose a new tumor.

For this type of biopsy, a doctor (usually an orthopedic surgeon) removes a piece of the tumor through a cut made in your skin.

• Incisional biopsy: only a piece of the tumor is removed
• Excisional biopsy: the entire tumor is removed

These biopsies are often done in an operating room using general anesthesia (medicine to put you into a deep sleep). They can also be done using a nerve block, which numbs a large area of your body.