South Australia’s long awaited proton therapy unit could be revived after fears it will be lost interstate.

Adelaide doctors claim a Victorian proposal is unsuitable for young children, prompting the federal health minister to concede the country may need two machines.

“We’re not looking at a question of either a Victorian or South Australian proton therapy unit but indeed we might need to look at both of them at the same time,” Health Minister Mark Butler told 7NEWS.

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The Adelaide proton therapy project collapsed after a dispute with supplier ProTom, despite hundreds of millions of taxpayer dollars being committed to the project.

7NEWS has extensively reported on the proton therapy saga, speaking with families forced to travel overseas to access the life saving treatment and those pushing governments to finally deliver a solution.

The Adelaide proton therapy project collapsed after a dispute with supplier ProTom. Credit: 7NEWS

Sophie was diagnosed with spinal cancer aged 10. Her only option was therapy in America, but she could not go. Credit: 7NEWS

Advocates for the unit were armed with more than 32,000 signatures when they met with SA Premier Peter Malinauskas on Thursday, calling for an end to delays.

“Kids, adults, anyone shouldn’t have to go through having to fight ... all of this,” Roger Camerini told media.

His daughter Sophie was just 10 when she was diagnosed with spinal cancer.

Her only option was therapy in America, but she could not go.

“Would it have been different if we had done it here? We’ll never know,” Camerini said.

SA Opposition Leader Ashton Hurn said “Australia is the last G20 country to not have one of these proton therapy units available”.

“We’ve just got to brush politics aside and get this done,” Hurn said.