A biopsy is where a sample of abnormal tissue is removed to help diagnose the type and grade of tumour you have. The sample is taken during an operation and examined under a microscope in a laboratory.
For brain tumours, sometimes a biopsy will be taken as part of a craniotomy. A craniotomy is an operation to remove all, or as much is safe, of your tumour.
However, depending on the location of your tumour, a craniotomy might not always be possible, so a smaller operation is performed to get a sample of the tumour for diagnosis. This operation is a surgical biopsy and is often called a burr hole biopsy.
The tumour sample will be sent to the laboratory to be analysed and diagnosed by a neuropathologist.
A biopsy generally takes about 1-2 hours and can often be done as a day case.
The results of your biopsy will show the type and grade of your brain tumour. This will allow your healthcare team to decide the best treatment for you.
What happens during a biopsy?
- First you will have an MRI scan or CT scan to show exactly where the tumour is.
The scan can be up to a few weeks before the biopsy operation.
- You will then be given either a general anaesthetic to fall asleep.
Occasionally the procedure is performed under a local anaesthetic, but you will be sedated. If this is thought to be your best option, your healthcare team will discuss it with you, explaining what is done to prevent you feeling any pain, and help you mentally prepare for it.
Types of biopsy
- Biopsy as part of a craniotomy - If you are able to have surgery to remove all or part of your tumour this is called a craniotomy. As part of this, your neurosurgeon may take a small sample of your tumour to send to the lab for testing.
- Guided needle biopsy - During a guided biopsy your neurosurgeon uses either a CT or MRI scan to locate and take a sample from the tumour. This can be done in 2 ways:
- Frame-based stereotactic biopsy – before your MRI or CT scan, you are fitted with a special frame around your head. Markers on the frame allow your surgeon to know exactly where to put the needle to remove a sample of the tumour.
- Frameless neuronavigation biopsy – after an MRI or CT scan, your surgeon is able to use a neuronavigation system (computer-assisted technologies) to pinpoint precisely where the biopsy should be taken from. You will then be given a general anaesthetic to fall asleep and a very small 'burr hole' will be drilled into your skull by the neurosurgeon. A needle is passed through the hole to take a small sample of the tumour, which is sent to the lab for analysis and diagnosis.
- Open neuronavigation biopsy - Sometimes a larger sample of the tumour might be needed, or if there is a high risk of bleeding, your surgeon may perform an open biopsy. This is for tumours which are on the surface of the brain, not deep inside. A neuronavigation system is used and a small part of your skull ('bone flap') is removed to give your neurosurgeon better access to your tumour. Samples are taken without passing a needle into the tumour. The hole is closed using staples or stitches.
After your biopsy, you may be given steroids to help with any brain swelling.
After a biopsy
After having a biopsy you may need to stay in hospital overnight or for a few days. However, sometimes a biopsy can be done as a day case and you will be allowed home that day.
If you have had a craniotomy, your recovery might take longer and you may need a longer stay in hospital.
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