Can a Bone Density Scan Help Detect Cancer Early?
A bone density scan, also called a DEXA scan, is used to measure bone density by detecting the amount of minerals in your bones. This determines if you are at increased risk of osteoporosis, a condition that causes bone loss and reduces bone strength.
So, if you are wondering, “Can a bone density scan help detect cancer early?”, the answer is no. A bone density scan is not the most appropriate imaging test for the early detection of cancer. However, there are other scans that can help identify abnormalities in bones and surrounding tissues.
Here, we will explore what DEXA scans are useful for and how they work. We will also discuss which imaging tests can help diagnose bone cancer.
How DEXA scans work
A DEXA scan or Dual-Energy X-ray Absorptiometry scan uses low doses of X-rays to create images of your bones. X-rays are a type of ionising radiation.
The amount of radiation that your body will absorb during a DEXA scan is equivalent to the amount of radiation you will absorb from being exposed to in everyday life for 3 hours. This is much lower than the amount of ionising radiation used in a standard X-ray.
During a standard X-ray, a single beam of X-rays is passed through your body. During a DEXA scan, two low dose beams of X-rays from different sources are passed through your body. This allows for greater accuracy in measuring your bone density.
Any X-rays that are not absorbed by your body pass through and are detected by the X-ray detector. The more dense your bones, the more X-rays they absorb and the lighter they appear on your DEXA scan image.
The X-ray detector sends the information it collects to a computer to create your DEXA scan image. The computer then generates a score that reflects your average bone density — this is called a T-score.
What to expect during your bone density scan
When you arrive for your bone density scan, you will be asked to remove any metal items as these can interfere with the scan. For example, metal hair accessories, jewellery and clothing with metal zips, clasps and buttons. Wearing comfortable clothing or a hospital gown may be required.
Then, you will be asked to lie back on an examination table. The DEXA machine has a scanning arm that will be passed over you. The procedure is painless and during this time, you will need to remain still.
If you are concerned about osteoporosis risks, your DEXA scan will usually involve scanning your hips and spine. However, other body parts may also be scanned such as your forearms, depending on your risk factors.
Your scan will be complete within 20 minutes and you can return to your usual activities straight away.
Understanding your DEXA scan results
As mentioned earlier, your DEXA scan image will be processed by a computer to generate a T-score that reflects your average bone density.
The T-score compares your average bone density to that of a young adult. It ranges from +1 to -2.5 and below:
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+1 to -1 – a T-score within this range means that your bone density is equivalent to that of a young adult (normal bone density)
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-1 to -2.5 – a T-score within this range means that your bone density is below what is normal for a young adult and you have osteopenia (low bone density)
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-2.5 and below – a T-score within this range means that your bone density is considerably below what is normal for a young adult and you have osteoporosis, which significantly increases your fracture risk.
Osteopenia refers to reduced bone density, a stage of bone loss that is not low enough to be considered osteoporosis. Osteopenia increases the risk of osteoporosis and means your bones are weaker than normal, raising your risk of fractures.
After your bone density scan, you will receive a report with your results and insights from one of our experienced doctors. At Vista Health, we aim to deliver your results within 3 working days. Your results can also be sent to your NHS GP.
A doctor can then advise you on whether or not you need treatment for reduced bone density. This will not only depend on your T-score but other factors, such as your age, lifestyle, medications, history of fractures and other medical conditions.
Do you need a bone density scan?
You may want to consider having a bone density scan if you have a family history of osteoporosis or fractures, or are taking medication that increases your risk of osteoporosis (such as certain cancer treatments).
If you already have osteoporosis, a private bone density scan is helpful to check the progress of your condition and/or treatment and track bone health.
You may also want to have a bone density scan if you have certain health conditions that increase your risk of developing osteoporosis, such as:
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A body mass index (BMI) less than 21
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An eating disorder
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An overactive thyroid
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Early menopause — this includes menopause due to a hysterectomy (surgical menopause)
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Inflammatory bowel conditions eg Crohn’s disease or ulcerative colitis
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Rheumatoid arthritis
A bone densitometry scan is not the most effective scan to have if you:
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Have a family history of bone cancer and unexplained bone pain (a dull, aching pain from deep within your body)
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Suspect abnormalities in your spine or surrounding tissues
However, there are other imaging tests that can help diagnose bone cancer.
Alternative scans for bone cancer detection
The most effective scan for the early cancer detection in bones is an MRI scan. It uses powerful magnets and radio waves to create highly detailed 3D images of the inside of your body. MRI can detect subtle changes in all body tissue types, including bone.
CT scans can also be useful in diagnosing bone cancer. They use X-rays and computer technology to create 3D images of the inside of your body. CT scans can be used to help guide a doctor when performing a biopsy (ie collection of a small sample of tissue for analysis in a lab) and to check whether bone cancer has spread to other organs eg the lungs.
X-rays are not usually used for the early detection of bone cancer (ie when a tumour is very small), but they can detect larger tumours, abnormalities and bone damage.
Ready for your bone density scan?
If you’re concerned about developing osteoporosis (brittle bones), a private bone density test can give you the information you need to protect your bone health. You can book your private DEXA scan at one of our clinics today.
Sources
https://www.radiologyinfo.org/en/info/safety-xray
https://medlineplus.gov/bonedensity.html
https://patient.info/bones-joints-muscles/osteoporosis-leaflet/dexa-scan