Tests
A number of different tests can be performed to assess people
who might have a GIST, to make the diagnosis and to make further
assessments to plan treatment. Our cancer care is provided as part
of a regional network. Patients may therefore have different tests
in different hospitals. As far as possible, we will minimise the
number of trips and travel distances required. However, we also
need to make sure we gather the correct information from the
different tests available to make the right treatment decision for
each patient.
Upper GI endoscopy
One of the most common way GISTs are diagnosed is when a person
is having an upper GI endoscopy (often referred to as an OGD) for
other symptoms. This is a common procedure involving the insertion
of a thin tube with a camera on the end through the mouth into the
oesophagus, stomach and first bit of the small bowel called the
duodenum. This test is important to look for a range of problems
such as acid damage or an ulcer. It is a routine procedure, but as
with any test there are benefits and risks, even though the risks
are low. More information on this procedure, its benefits and risks
are available
here.
Computed Tomography (CT)
Another common way GISTs are diagnosed is when a person has a CT
scan. A GIST may be detected when someone is having a CT scan for
other symptoms that are not related to the GIST. A CT scan is also
an important part of assessing a GIST to check the size of the
tumour and look for any evidence of spread. Having a CT scan
involves lying down on a narrow bed which moves through an open
ring, like a big doughnut. The scan itself usually takes a few
minutes. It involves exposure to x-rays, a form of ionising
radiation. Doctors always minimise the amount of radiation to which
patients are exposed. For people with a GIST, the benefits of this
test and the information it provides to plan treatment outweigh its
risks.
Endoscopic Ultrasound (EUS)
Sometimes, patients require a more invasive form of scan called
an Endocsopic UltraSound or EUS. This procedure is performed under
sedation in the endoscopy department. A telescope with a very small
ultrasound probe on the end is passed through the mouth into the
oesophagus, stomach and /or duodenum to get close up pictures of
the GIST. In addition to having a very close look at the GIST, this
procedure can be also be used to take small samples (or biopsies)
of the tumour to confirm that it is a GIST. It can take up to 2
weeks for any samples to be examined under a microscope and receive
the result. As EUS is an invasive test, there are small risks
associated with the procedure, which the team will explain to you
if you are having this test.
Other tests
Occasionally, other tests are required. These may be required to
look at specific areas identified by the above tests. For example,
the scans may detect an abnormal area on the lower bowel. This may
then mean that a telescope examination of the lower bowel is
required to know exactly what is going on at the abnormal area. In
addition, tests may be required to help assess fitness for
treatments. These include tests to examine how well the heart or
lungs are working, to know if a person is fit enough to have major
surgery. Your doctor will explain any additional tests and why they
may be needed.
