A new medical development in Adelaide will be home to a proton therapy device that will improve the treatment of tumours as well as cut costs to patients.

Cancer treatment across the Asia-Pacific will be "revolutionised" with reduced costs and better outcomes, thanks to a new medical precinct development under way in Adelaide.

Work has begun on the Bragg Centre, which will house a proton therapy device, designed to target tumours more precisely while sparing surrounding tissue and organs, reducing side-effects and improving long-term results.

ProTom International will install the Radiance 330 device and chief executive Stephen Spotts says once operational, it will transform cancer treatment.

"The Radiance 330 will revolutionise cancer treatment not only in South Australia, or even Australia but across the Asia-Pacific region," he said in a statement on Wednesday.

"Once the Bragg Centre is open and operational, cancer patients will be referred there to take advantage of the advanced proton therapy the device offers."

Director of the South Australian Health and Medical Research Institute Steve Wessling said extensive testing would be conducted on the proton device once its "bunker" was complete.

"Proton therapy beam is more exact and does not scatter or cause damage to surrounding tissue," he said.

"We expect about half the patients in this unit will be children who would have otherwise gone overseas or been treated with radiotherapy, which has consequences of long-term damage."

Treatment that would normally cost up to $250,000 in the US could fall to as low as $40,000 if conducted in SA.

The Bragg Centre is expected to be completed by 2023, with the first patient to be treated about 18 months later.

Launching construction on Wednesday, Premier Steven Marshall said the project was an Australian first and the $500 million build would create 1000 construction jobs.

Overall, the project was expected to generate more than $1 billion in economic activity.

"This significant development will put SA on the map as a pioneer in world-leading, lifesaving proton therapy cancer treatment," Mr Marshall said.