A mum's desperate plea for the legalisation of medicinal marijuana.

This week, Victoria became the first state in Australia to legalise medicinal cannabis in exceptional circumstances.

But for 17-year-old Lindsay Carter, suffering from a terminal brain tumour, frequent seizures and chronic pain, it’s too little, too late.

On last night’s 60 Minutes, Lindsay’s mother Lanai Carter made a desperate plea to save her son.

For Lindsay, chemotherapy is not an option, and surgery will only worsen his condition. The only thing that improves his quality of life is medicinal marijuana – and he can’t get it.

“When Lindsay is able to have medical cannabis, it makes a huge difference to his quality of life,” says his mother. “It reduces his seizures, it manages his pain and his nausea – and one really major thing is that it actually helps to stimulate his appetite.”

While traditional cancer treatments aren't appropriate for Lindsay's condition, there is one thing that appears to have an effect on his tumour: a controversial cannabis oil, which his family travelled to the United States to obtain.

That treatment shrunk his train tumour by an astounding 7mm - but, like other marijuana, it's illegal where Lindsay lives in Queensland.

"We've been to the US four times in 2014," Lanai Carter told 60 Minutes.

"That took a tremendous toll emotionally, financially on our family. We wiped out our superannuation trying to get our son to a country where he can get this treatment legally. And it's just been incredibly hard."

Watch a snippet of last night's episode of 60 Minutes below (post continues).

The family hasn't been able to make the trip to the US since 2014 for financial reasons. Meanwhile, Linday's tumour is growing and his condition is deteriorating.

The family's only hope was to petition the Federal Government to allow the import of the cannabis oil for Lindsay's use. After a year of work, her application was granted - only to be met by more bureaucratic red tape at the State level.

Despite being approved by the Federal Government for Lindsay's use, the Queensland Government must now approve the medicine.

"They are putting my son's life at risk by playing God," Carter says.

"Queensland is just trying to do the same process over again, and it's unjust that they should put any patient through that."

Queensland Health, for their part, say they have an obligation to be as "thorough as possible" - but what terrible risk they're searching for remains unclear in a terminal case like Lindsay's.

"I would never want other families to have to go through what we've had to go through to try and treat a child with a medicine," Carter says.

"It's just insane."