Ollie was just three years old when his father, The Angels guitarist Chris Bailey, died of throat cancer. Ollie was only six when he was diagnosed with brain cancer.

“I just thought what a scary world it must be for him, to lose your dad and then brain cancer at six, what a scary place, I just felt so sad for him,” Ms O’Reilly said.

Ollie had a tough road ahead at The Sydney Children’s Hospital. Brain surgery removed the tumour and then he needed radiation every day for six weeks, each day requiring a general anaesthetic.

“For the parents, it’s the big picture — you know, my child has brain cancer. But for the kids it’s the procedures, every day, but the nurses were just so good at managing the routine, so much so, he wanted just one more treatment after he had finished,” she said.

Four months of chemotherapy was also required but, two years on, Ollie is doing well.

Although he needs scans every three months, he is at present cancer-free.

“I’ve never in my life felt so grateful. They saved him but it is the way they saved him, the music therapists and the nurses, the way they found the right way to talk to a six-year-old,” she said.

The hospital’s Gold Appeal will help research into brain cancer.

Brain cancer is one of the most lethal of all childhood cancers, which is why more research needs to be done. Unlike childhood leukaemia, which now has a survival rate up to 90 per cent, survival rates for brain cancer have not improved in decades. Only one in five survive.

Present treatments also have lasting effects on growing bodies.

Sydney Children’s Hospital Oncologist Associate Professor Richard Cohn said Ollie was doing very well.

“I’m very happy with his progress, he doesn’t seem to have too many complications from the surgery, radiation and chemo, he has tolerated them very well and is leading as normal a life as we could hope,” he said.

Ollie’s form of brain cancer, Medulloblastoma, was once thought to be just one disease, but research has identified four subtypes, which means more tailored treatments. Research into personalised medicine is at the forefront, he said.

“We are really are fortunate, but it is early days. If it is hope versus despair, we are on the hope end,” she said.

“To see him now, he is back at school. The kid he is now, and who he will be, is shaped by the hospital and the way the staff build the kid’s resilience is amazing.”

Like his dad, Ollie is a talented musician, rocking out the tunes of Queen on his ukulele.

* To help the hospital’s efforts to research brain cancer, and other diseases affecting children, go to goldappeal.org.au

Follow Jane Hansen on Twitter @janehansen2000 or email jane.hansen@news.com.au