There's a long way to go before the 19-year-old is officially in remission, but the oncothermia treatment has brought renewed hope to a family that had been told by doctors there was nothing more they could do.

Cass, as she prefers to be known, has undergone three operations in as many years to remove brain tumours under high profile neurosurgeon Dr Charlie Teo.

UOW probes success of oncothermia

The former St Mary's College student suffered through countless rounds of chemotherapy and radiation - even travelling to the United States for experimental treatment. But the tumours came back within a couple of months of surgery.

In February this year, after her third surgery, she began oncothermia treatment and she hasn't looked back.

The treatment, which involves using heat and electromagnetic fields to destroy and weaken cancer cells, has been used successfully in other countries for about 20 years but has only recently become available in Australia.

"Oncothermia is totally different to chemotherapy, which made me vomit and want to sleep all the time and put me in a constant bad mood," Cass said.

"I'm on my second lot of oncothermia treatment, which involves travelling to Prince of Wales Private Hospital three times a week for an hour of treatment.

"You basically lie on a waterbed with a paddle attached to your head which heats up and delivers the treatment. There's no side effects and I feel better than I have in years."

It was in late August 2010 that Cass was raced to the emergency department at Wollongong Hospital suffering nausea, back pain and double vision.

A registrar refused to authorise a brain scan, believing the symptoms were stress-related, and she was discharged - although a subsequent inquiry found she was improperly treated.

Her parents Gloria and Joe arranged a private scan that uncovered a massive brain tumour, which was removed by Dr Teo at Prince of Wales Hospital less than a week later.

Within six weeks of the surgery, however, the tumour had grown back and spread down her spine. Intensive chemotherapy and radiation followed - then the terrible verdict.

"The doctors told us there was nothing more they could do. She'd already been hit with the hardest treatment available," Mrs Nascimento said.

But the family would not give up. Another surgery followed in September 2012, and then they took Cass to the Burzynski clinic, Texas, for months of antineoplaston treatment.

But back home, on December 30 last year, Cass woke up and couldn't talk or walk. Tests revealed the tumour was growing again. Oncothermia was the last option.

"Dr Teo operated again on February 13 and then Cass started oncothermia. Since then her scans have been clear."

"We are really hopeful - and while we don't know for sure that it's going to work, at least we've got the chance to try something different." Mrs Nascimento said.

Because of the lack of side-effects, Cass is now able to live her life - even joining her family on a European holiday next month.

"I'm not too scared to go on holiday now," Cass said.