A bone scan is a nuclear medicine test used to diagnose many different kinds of bone problems and diseases. The procedure uses a small amount of a radioactive substance called a tracer, which shows possible bone damage in areas where too much or too little tracer has been absorbed by the body. The reason your doctor may run a bone scan during your diagnostic testing is to see whether that bone damage could involve cancer.
Using a bone scan when cancer is suspected can be particularly helpful because the scan can find both primary cancer—or, cancer that started in your bones—and bone metastases, which is cancer that has spread to the bones from another part of your body. Some cancers that might involve bone metastases include breast cancer, lung cancer, lymphoma, and others. A bone scan can also find changes in your bones much earlier than they might be noticed using a regular x-ray.
Another reason your doctor might request a bone scan is if you have already been diagnosed with bone cancer. That’s because a bone scan can be used to monitor how well your bone cancer treatment is working.
For the scan itself, you may go to a hospital’s radiology department or nuclear medicine department or to an outpatient imaging center. Before your bone scan, you’ll be given a small amount of tracer through a vein in your arm. It will take anywhere from 1 to 4 hours to absorb. Then, you will usually get a bone scan of your whole body, which takes about 1 hour to complete.
During the bone scan, the tracer gives off a type of radiation called gamma radiation, and a camera scans the body and detects this radiation. Healthy bone appears lighter in the scan. Areas where too much or too little tracer has been absorbed by the body stand out on the image and are called “hot spots.” Those hot spots signal that bone damage is present, which could indicate bone cancer or bone metastases. If your bone scan does show bone damage, then your doctor might recommend further testing. Talk with your doctor before the scan about why you are having it, any special test preparations you may need to take, and what the results could mean for your cancer care.