Gamma knife radiosurgery

Gamma Knife radiosurgery is an established stereotactic radiosurgery (SRS) technique for tumours, vascular malformations, and other abnormalities of the brain. The Gamma Knife is a radiation therapy machine which can deliver large doses of precisely targeted radiation, minimising radiation to the surrounding healthy brain reducing the risk of damage.¹

Gamma Knife radiosurgery delivers multiple converging beams of gamma radiation toward a central point to deliver high dose radiation to a specific target within the brain and, avoid delivering significant doses to normal brain tissue.¹

Gamma Knife radiosurgery is used to treat a variety of brain disorders. Your treatment team are neurosurgeons and radiation oncologists, radiation therapists, physicists and nurses with specialised training in the treatment of neurological conditions, as well as other healthcare professionals. 

The team will work together to decide if this is an appropriate treatment option for you after careful evaluation of your condition, ensuring you are eligible based on all clinical circumstances.

Eligible conditions may include (but are not limited to):

• Brain metastases
  
• Meningiomas
• Pituitary adenomas
• Acoustic neuromas
• Arterial venous malformations
• Trigeminal neuralgias

Gamma Knife may not be suitable if:

• The treatment area is too large
• The lesion that needs treatment is too close to important critical structures in the brain .
  

• Gamma Knife enables the treatment of hard-to-reach brain tumours that may not be easily treated with conventional surgery.
• SRS may have benefits over conventional whole-brain radiation therapy. By limiting radiation to the surrounding healthy brain tissue, SRS aims to reduce immediate and late side-effects, and thereby offer a better quality-of-life^.2
• You should be aware that radiosurgery is a serious medical treatment and comes with risks and side effects which should be discussed with your doctor. Studies have shown that Gamma Knife treatment may result in fewer side effects than conventional radiotherapy.  

Side effects may vary between patients and your doctors will advise of which side effects to expect.

Not everyone experiences side effects, but your risk may be affected by your general health, other treatments you’ve had and the targets to be treated.

If you choose to have Gamma Knife radiosurgery after consultation with your doctor, the following process is likely to apply with respect to Gamma Knife radiosurgery, planning and treatment.

Treatment preparation

On arrival at the centre you will meet your treatment team, go through an orientation of the clinic floor and complete your health and nursing assessment. 

Fitting your head frame

You’ll be fitted with a head frame to improve the accuracy of your radiosurgery and keep your head still during treatment. The frame will be fitted on the same day as your treatment.

Head frame fitting

Your consultant will inject local anaesthetic into four places on your head. Once the areas are numb, they’ll attach the frame to your head with four screws. It takes around 15 minutes to fit, and you’ll keep it on until your treatment has finished. You may feel pressure, but once the frame is fitted this will disappear within 15-20 minutes. You may also feel some discomfort where the frame was attached to your head after your treatment has finished and the local anaesthetic has worn off, which usually only requires mild analgesia.

1. Desai R and Rich K. Mo Med 2020; 117(1):33-38.
2. Brown P, et al. JAMA 2016; 316(4):401-409.
3. Yamamoto M, et al. Lancet Onc 2014; 15(4):387-395.