How does Gamma Knife radiosurgery work?

Gamma knife is a form of stereotactic radiosurgery

Radiation can be delivered in different forms. The most focussed and targeted is termed ‘stereotactic radiosurgery’. For well circumscribed, deep seated tumours, this is the best option as this form of treatment can target a high dose of radiation to the tumour, whilst minimising any spread to the "normal" brain.

Gamma knife radiosurgery - non-invasive surgery

The most common form of stereotactic radiosurgery is called ‘Gamma knife radiosurgery’. This technique achieves the highest level of accuracy by using a stereotactic frame that is fitted to the head during the treatment. The other advantage of radiosurgery is that it is non-invasive, and so in some circumstances avoids the need for open surgery. It is convenient and performed as a day case. However, it does have some limitations and cannot be used to remove a tumour that is already causing symptoms. The aim is to arrest growth. As a general rule of thumb, a tumour that is less than 3cm in size can be considered for radiosurgery. Smaller is better for this treatment type, as larger tumours can be susceptible to swelling reactions in the brain. Larger or more diffuse tumours may be suitable for ‘fractionated’ radiotherapy instead.

Centres of stereotactic radiosurgery excellence include - Queen Square Radiosurgery Centre, National Hospital for Neurology and Neurosurgery (NHNN)