Brain cancer diagnosis and tests

Examinations and tests

The findings of your medical interview and physical examination will probably suggest to a doctor, whether your GP or an accident and emergency doctor, that you have a problem with the brain or brain stem.

•  In most cases, you will have a CT scan of the brain.
•  This test is like an x-ray but shows more detail in three dimensions.
•  Usually, a harmless dye is injected into your bloodstream to highlight abnormalities on the scan.

People with brain cancer often have other medical problems; therefore, routine laboratory tests may be performed.

•  These include analysis of blood, electrolytes, liver function tests, and a blood coagulation profile.
•  If you have mental state change as the main symptom, blood or urine tests may be carried out to detect drug use.

More and more, the MRI scan is being used instead of CT scan for suspected brain tumours. This is because MRI has a higher sensitivity for detecting the presence of, or changes within, a tumour.

Skull x-rays are not widely used any longer to diagnose brain cancer.

If your scans indicate the presence of a brain tumour, you will be referred to a specialist in cancer (oncologist). If one is available in your area, you should be referred to a specialist in brain tumours (neuro-oncologist).

The next step in diagnosis is confirmation that you have a cancer. A small sample of the mass (a biopsy) is taken to identify the type of tumour.

•  The most widely used technique for obtaining a biopsy is surgery. The skull is opened, usually with the intention of removing the whole tumour if possible. A biopsy is then taken from the tumour.
•  If the surgeon is unable to remove the entire tumour, a small piece of the tumour is removed.
•  In some cases it is possible to collect a biopsy without opening the skull. The exact location of the tumour in the brain is determined stereotactically, that is, by using CT of MRI scan while the head is held still in a frame. A small hole is then made in the skull and a needle guided through the hole to the tumour. The needle collects the biopsy and is removed. This technique is called stereotaxis, or stereotactic biopsy.
•  The biopsy is examined under a microscope by a pathologist (a doctor who specialises in diagnosing diseases by looking at cells and tissues).