Radiotherapy for secondary brain cancer

When cancer has spread to the brain from elsewhere in the body, it is called a secondary brain tumour or a brain metastasis.

Cancer growing inside the brain increases pressure inside the skull. This can cause symptoms such as:

• a bad headache

• sickness

• increasing drowsiness

Radiotherapy is a common treatment for secondary brain tumours. It aims to shrink the cancer, relieve the pressure inside your skull, and reduce your symptoms. 

Your doctor might suggest that you have radiotherapy to the whole of your brain. This is because it's likely that there might be cancer elsewhere in the brain that is too small to show up on a scan.

How you have treatment

You have radiotherapy to the brain as a course of daily treatments called fractions. It is likely to be 1 to 2 weeks of daily treatments. But this can vary. 

You have a CT planning scan so the treatment team can plan exactly where to give the radiotherapy. For this scan you will have a mould made which helps to keep you in the right position. It also makes sure that the treatment is delivered accurately each day. They put marks on the mould to help with positioning you for the treatment.

Read about planning radiotherapy

Having treatment

The radiotherapy machine is called a linear accelerator. To have the treatment you lie on the radiotherapy couch. The therapeutic radiographers help you to get into the right position.

It is very important that you keep perfectly still. You will have your plastic mould or mask to wear to help with this.

While you are lying down, the plastic mould is put over your face and head and onto the radiotherapy couch. It makes sure that you don’t move in the middle of your treatment.

Once you are in the correct position the radiographers then leave the room. This is so they are not exposed to the radiation. You will be alone for a few minutes while you have the treatment, but they can see and hear you the whole time.

It is important that you keep still and breathe normally. Sometimes there may be a delay in starting the radiotherapy. This is due to the radiographers taking an x-ray picture before treatment to check your position.

You won't feel anything during the radiotherapy. The radiotherapy couch is usually quite hard, which can be uncomfortable.

Some people with secondary brain cancers have stereotactic radiotherapy. This gives radiotherapy from many different positions around the body, with the radiation beams meeting at the tumour.

Read more about stereotactic radiotherapy

Treatment results

Radiotherapy treatment to control symptoms of brain cancer might take a few days or weeks to work. The radiotherapy might cause swelling at first. This might make your symptoms seem as though they are getting worse.

Your doctor will usually prescribe steroids during your radiotherapy to help with the swelling. 

The radiotherapy might also help to stop new areas of cancer developing in the brain. So although you won't notice it, the treatment may be stopping the situation from getting worse. 

Side effects of radiotherapy for brain cancer might not come on straight away. Side effects tend to come on gradually as you progress through your treatment and for a few weeks afterwards. They can include:

• hair loss in the treatment area - it usually will grow back

• skin reaction on the scalp

• sickness - you can take anti sickness medicine during treatment to help

• drowsiness

• fits (seizures)

• headaches

Read about steroids

Side effects of brain radiotherapy

Tell your doctor or radiographers about any side effects you are experiencing. They can help you to manage them. 

Radiotherapy side effects