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Cyberknife is a specialised radiotherapy machine mounted on a robotic arm and is used to give stereotactic radiosurgery/therapy (SRS/SRT) and stereotactic ablative body radiotherapy (SABR) treatments.

We use cyberknife to deliver SRS/SRT to brain metastases which are cancer deposits that have spread to the brain from a primary cancer elsewhere in the body. Cyberknife also delivers SABR treatments to extracranial tumours (areas outside the brain).

The accuracy of cyberknife means that a high dose of radiotherapy can be focused on a very precise area. In the same way that having a normal X-ray does not hurt, the patient will not feel anything whilst having treatment on cyberknife.

What is CyberKnife Stereotactic Radiosurgery/therapy?

Stereotactic radiosurgery/therapy is a highly focused and accurate treatment which involves targeting multiple high energy X-rays at cancer deposits that are visible on a patient’s MRI scan of their brain (intracranial disease).

The aim is to destroy the cancer cells within the targeted region in one or three daily treatments. If a single treatment is given it is called stereotactic radiosurgery (SRS). Three treatments is known as stereotactic radiotherapy (SRT).

Stereotactic radiosurgery/therapy is best suited for patients with small, well-defined tumours. There is a strict eligibility criteria set out by NHS England that we are required to follow:

  • performance status 0 or 1
  • cancer diagnosis with absent or controllable primary disease
  • pressure symptoms best relieved with surgery are excluded
  • tumour volume <20cc
  • prognosis > 6 months

What intracranial conditions do we treat using SRS/SRT?

  • Brain metastases (secondary cancer deposits from a cancer elsewhere in the body)
  • Acoustic neuroma
  • Meningioma
  • Pituitary tumours
  • Glomus tumours

What needs to happen before I start intracranial Stereotactic Radiotherapy?

After consenting for treatment with a neuro-oncologist, two planning appointments will be organised. The first appointment will be in the mould Room, to have a mask to help keep the head still and in the correct position for treatment. A planning CT scan will then be done wearing this mask; this appointment takes approximately 1.5 - 2 hours.  The other appointment is for a planning MRI scan. Often these appointments will be arranged on the same day.

Treatment will normally commence one to two weeks after the planning scans have been performed. One difference between standard radiotherapy and SRS/SRT is that the treatment is usually much longer and can range from approximately 45 minutes to several hours depending on each patients specific plan.

Cyberknife uses X-ray cameras to monitor the patients position during treatment every 15-30 seconds; the robot is able to make corrections for any slight movements. The advantage of imaging during treatment in this way means that the patient can take a break whenever they require which is favourable during long treatment times.

What is CyberKnife Stereotactic Ablative Body Radiotherapy (SABR)?

SABR is an effective way of giving focused radiotherapy, increasing the chance of controlling the tumour whilst sparing the normal tissues.  It does this by using:

  • fewer treatment sessions (either 3, 5 or 8 on alternate days)
  • smaller radiation treatment fields
  • higher doses of radiation

Conventional radiotherapy is the typical alternative treatment to SABR which can consist of 20 daily treatments over 4 weeks.

What needs to happen before I start SABR treatment?

All patients will need to attend a planning appointment for a CT scan after they have seen an Oncologist and consented for treatment.  Depending on the site being treated it may also be necessary to have a planning MRI scan which could involve a separate visit to the hospital.

There are strict criteria that must be met for a patient to be suitable for SABR treatment on cyberknife.  Referrals that come under oligo-metastatic disease are reviewed against the criteria set out by NHS England's Commissioning through Evaluation (CtE) programme.

Each patients’ case will be discussed in the relevant multi-disciplinary team (MDT) meeting to assess suitability. 

What conditions do we treat using SABR on CyberKnife?

  • Primary lung tumours - The patient requires a CT planning scan; inhale and exhale scan
  • Prostate cancer - *currently only treating private patients* (not commissioned by the NHS) - Patients require fiducial markers to be inserted into the prostate. Approximately 7 - 10 days later they require a planning CT and MRI
  • Kidney cancer - Patients will need fiducial markers to be inserted into the kidney followed by a planning CT approximately two weeks later
  • Oligo-metastatic disease (refers to patients with a limited number of metastatic sites, usually ≤ five sites) – These sites include:
    • Lung secondary tumours (the patient requires a CT planning scan; inhale and exhale scan)
    • Lymph nodes within 2cm of the spine (the patient requires a CT planning scan; inhale and exhale scan)
    • Spine (the patient requires a planning CT and MRI scan)

Other sites of metastatic disease including adrenal, liver and pelvic lymph nodes are treated with SABR on other treatment machines (linear accelerators) but they are not suitable for treatment on cyberknife.

Treatment times can be long for SABR treatments with treatment taking up to 1 hour 30 minutes or longer due to the higher doses in fewer treatments.

CyberKnife for health professionals/referrals

If you are a health professional and would like to make a patient referral for SRS or SABR, please contact the cyberknife team to request the relevant referral form.

Contact the CyberKnife team directly

For further information on cyberknife treatment at the Queen Elizabeth Hospital Birmingham (QEHB), or for referral information, please contact us via the details below:

CyberKnife Suite

CyberKnife Administrator

Available Monday, Wednesday and Friday from 08:00 - 13:00.

CyberKnife Lead Radiographer

An answer machine is available, please leave a message if you do not receive an answer.

Last reviewed: 05 March 2024