Further tests for primary bone cancer
If your tests show that you have bone cancer, the doctor may want to do some further tests to see whether the cancer has spread outside the bone.
CT (computerised tomography) scan
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Most patients with bone tumours will have a CT scan of their lungs. They might also have a CT scan of the affected bone.
A CT scan takes a series of x-rays, which build up a three-dimensional picture of the inside of the body. The scan takes 10-30 minutes and is painless. It uses a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You might be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. It’s important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection.
You’ll probably be able to go home as soon as the scan is over.
Hear from a superintendent radiographer in CT, and Jyoti, a CT scan patient, about what to expect when having a CT scan.
This scan looks at all the bones in the body. It’s more sensitive than an x-ray, and it shows up any abnormal areas of bone more clearly.
A small amount of a radioactive substance is injected into a vein in your hand or arm. Abnormal bone absorbs more radioactivity than normal bone, so these areas are highlighted and picked up by the scanner as hot spots. The level of radioactivity used in the scan is very small and doesn’t cause any harm to your body.
After you have the injection, you will need to wait 2–3 hours before you have the scan. You may want to take a magazine, book or MP3 player with you to help pass the time.
If hot spots do show up on a bone scan, it isn’t always clear whether they’re caused by cancer or by other conditions, such as arthritis. Sometimes a CT scan or MRI scan may help the doctors decide whether changes on a bone scan are caused by bone cancer or by another condition.
Some hospitals or treatment centres may do an MRI scan of the whole skeleton instead of a bone scan. This is to check for signs of cancer in any other bones away from the main tumour.
You will only need this test if you have, or are likely to have, Ewing’s sarcoma. Very occasionally, a Ewing’s sarcoma can spread to the bone marrow.
The test involves a doctor taking a small sample (biopsy) of bone marrow from the hip bone.
Before the test, adults will be given a local anaesthetic injection into the area around the bone to numb it. Children will usually have a general anaesthetic. The doctor will then pass a special needle through the skin into the bone. When the needle is in position, the doctor will draw a small liquid sample from the bone marrow into a syringe. You may feel some discomfort when this is being done, but it should only last for a few seconds. You can have painkillers if you need them. The test is usually done in the outpatient department and takes about 10–15 minutes.
Sometimes the doctor needs to take a small core of bone marrow. In this case they will do a procedure called a trephine biopsy, which takes a few minutes longer than a bone marrow sample. A special type of needle is passed through the skin to the bone marrow. The needle has a tip that can cut out a sample of the bone marrow. You may feel bruised after the test and have an ache for a few days. Taking mild painkillers will help ease it.
Sometimes the bone marrow and trephine biopsies are done at the same time.
Your bone marrow samples will be sent to a laboratory to be looked at under a microscope. It may take 7–10 days to get the results.
This is a combination of a CT scan and a PET (positron emission tomography) scan. A PET scan uses low-dose radiation to measure the activity of cells in different parts of the body.
PET/CT scans give more detailed information about the part of the body being scanned. You may have to travel to a specialist centre to have one. You can’t eat for six hours before the scan, although you may be able to drink. Before the scan, a mildly radioactive substance is injected into a vein, usually in your arm. The radiation dose used is very small. After having the injection you’ll have to wait at least an hour before the scan. The scan usually takes 30–90 minutes. You should be able to go straight home afterwards.
For people with primary bone cancer, the most common place for the cancer to spread to is the lung. A chest x-ray can show whether the lungs have been affected.
If you’re going to have chemotherapy, you will also have tests to check your hearing, kidneys and heart.
Some chemotherapy drugs can affect how well you hear high-pitched sounds. So you may have hearing tests (audiograms) before and during your course of chemotherapy.
To check how well your kidneys are working, you may have a small amount of mildly radioactive liquid injected into a vein in your hand or arm. This is carried through your kidneys then passed out in your urine. A few hours after the injection, a nurse will take blood samples from you. These will show how well your kidneys are working.
You may also have an electrical trace taken of your heartbeat (an ECG), an ultrasound scan of your heart (echocardiogram) or a MUGA (multiple-gated acquisition) scan. A MUGA scan shows the movement of the heart and is used to check your heart function. If you need a MUGA scan, your doctors will tell you more about it.