Before specialists decide on the
best way to treat your child, various tests will be done to diagnose and 'stage' the
cancer. They also assess your child's general health, as this may affect how treatment is
planned. The tests enable the specialist:
- To be quite sure that the correct cancer has been diagnosed.
Sometimes it is very difficult to be certain of the exact type of cancer, and for this
reason further opinions from doctors in other parts of the country may be sought. You can
be confident that your own doctor has the support of other experts around the country
through the UKCCSG.
- To find out exactly where the tumour is and whether it has
spread to other parts of the body. This is called staging. The tests involved may delay
the start of treatment for a few days, but without this information the right treatment
cannot be chosen. Usually starting treatment is not a matter of urgency. It is much more
important to get all the necessary information together and so ensure that the right
treatment is given.
Each different test is now explained. Some of these tests are
repeated during the course of treatment to study progress and check for any side effects
of treatment.
Biopsy
If it is suspected that a tumour is malignant (cancer), the surgeon may remove part
of it, either by inserting a special needle through the skin (needle biopsy) or by
doing a small operation (open biopsy). The specimen obtained is examined by the
histopathologist (person who studies body tissues) who can tell whether or not it is
malignant and exactly what type of tumour it is. It usually takes several days to get the
results of biopsies. Sometimes the surgeon may be able to remove the whole tumour rather
than just taking a biopsy.
Blood tests
Blood tests are done at the time of diagnosis and often during the following years to
check the effects of treatment. Blood samples are sent to a number of laboratories for
different tests. In the haematology department the blood cells are counted and this
is one of the main ways in which the side effects of treatment are monitored.
Microbiologists (people who study germs) may check the blood to see whether there is
infection and this is called a blood culture. The blood may also be examined in the
chemistry laboratory so that certain salts and chemicals in it can be measured, which
gives information about kidney and liver function for example. Blood samples may also be
used to cross-match blood in case a transfusion is necessary during treatment.
Bone marrow aspirate
In several cancers, the bone marrow may be affected. To tell whether or not it is
affected, a needle is put into the bone of the hip and some of the marrow is drawn out and
taken for examination in the laboratory. This test is usually done under a general anaesthetic
or heavy sedation, to avoid any discomfort to your child. Older children may prefer local
anaesthetic.
Lumbar puncture
In some conditions such as leukaemia (cancer of the white blood cells) or lymphoma (cancer
of the lymph system), malignant cells can pass into the cerebrospinal fluid
(which surrounds the brain and the spinal cord). To find out whether this has occurred, a
few drops of the fluid are removed by inserting a fine needle into the back between two
vertebral bones in the lumbar (lower) spine. A lumbar puncture is usually done under an
anaesthetic and sometimes drugs are injected into the fluid at the same time as part of
the treatment.
X-rays
There are various ways of examining what is happening in different parts of the body. An
ordinary x-ray can show whether there is a tumour in the chest, abdomen or bones as tumour
tissue looks different on x-ray from ordinary tissue. Sometimes special dyes are injected
into one of the child's blood vessels to get an even better picture.
Ultrasound scan
Ultrasound waves are sound waves that the human ear cannot hear. A special machine directs
the waves at a certain part of the body. The sound waves are then converted into a picture
which helps to tell healthy tissue from a tumour. Ultrasound scans are completely safe and
are used particularly to look at the abdomen and heart.
Bone scan
Small doses of a radioactive substance can be injected into a vein to show up abnormal
areas in the bones. If your child has a bone tumour or a tumour which has spread to bone,
a scan will show how much of the bone is affected.
CT scan
A CT (computerised tomography) scan is a method of taking pictures of soft body tissue.
Pictures of the part of the body to be scanned are taken from different angles by a camera
in a rotating drum. A computer integrates the pictures to reveal any tumours. Scanning is
painless but your child may be given a sedative or general anaesthetic to ensure that he
lies still.
MRI (magnetic resonance imaging)
Magnetic waves are altered in different ways as they pass through the body depending on
the type of cell.
MRI scanning builds up a series of cross section pictures of
the body. The process is harmless and painless, but the machine is noisy and looks
frightening, as the patient has to lie in a tunnel. Your child may be given a sedative or
general anaesthetic to make sure that he lies still. |