Early data from Macquarie University Hospital’s gamma knife treatment for AVM is showing results in line with international best practice.

Gamma Knife surgery has revolutionised the management of many complex or inoperable brain conditions – including arteriovenous malformation (AVM).

While smaller AVMs are removed surgically, larger ones and those buried deeper in the brain are now best treated by stereotactic gamma knife radiotherapy. Gamma knife damages the endothelial cells, which, in turn, increases smooth-muscle cells and extra-cellular collagen.

The neurosurgery team at Macquarie University Hospital has now treated 20 AVMs since commencing its gamma knife service ten years ago. Eighteen of those have been treated from within the past two years, so follow-up is still short.

However, results are promising and in-line with international studies. To date, one AVM has been completely obliterated on digital subtraction angiography (DSA). Four have been obliterated on MR angiogram, with doctors waiting a longer period before DSA is performed.

Eleven have decreased in size with reduced flow through them and four have not had follow up imaging yet. “This is encouraging that the lesions we have treated are

responding as predicted in comparison with worldwide treatment data,” said Dr Fuller, Macquarie University Hospital’s leading gamma knife neurosurgeon.

Follow-up is at 2, 3, 5 and 10 years with international data showing about an 80 per cent obliteration rate by year 10.

For remaining patients, risk of haemorrhage is reduced for the duration of their life.