Brisbane's Princess Alexandra Hospital is about to become the first public medical facility in Australia to use a machine that treats brain cancer without invasive surgery.

The Queensland Government has paid $4.3 million for a machine called a Gamma Knife, which is due to arrive at the hospital in July.

Cancer specialists at the hospital said it would drastically alter tumour treatment by offering them a way of targeting hard-to-reach tumours for patients unfit to undergo traditional surgery.

Princess Alexandra chairman of neurosurgery Dr Bruce Hall is quick to point out "it's not a knife".

"Focused beams of radiation are directed to the treatment area in the brain and the shape and dose of the radiation is designed to hit the target without damaging surrounding healthy tissue," he said.

Brain cancer is one of Australia's most deadly diseases, claiming the lives of more children and adults under the age of 40 than any other disease, according to the Australian Institute of Health and Welfare.

But unlike leukaemia and breast cancer, the mortality rate for brain cancer has not fallen over the past 20 years.

Oncologist Dr Matthew Foote described the Gamma Knife as the gold standard for brain surgery, saying it would be of great benefit to Queenslanders.

"There is no doubt in my mind this is the safest way to deliver what's called radio surgery which is this type of treatment of minimally or non-invasive radiation to abate tumours," he said.

"We have a lot of patients in regional centres - they should be able to come in and have treatment then be home on the same day.

"There will be no need to have extended periods away from family and friends."

The machine can also be used on benign and cancerous tumours in other parts of the body.