An Ottawa radiation therapist is using her artistic skill to help ease the suffering of children with cancer.

Gerry Ash spends hours of her own time turning a form-fitting radiation mask into a treasure for young people with brain tumours.

During treatment, the mask allows radiation to penetrate the exact part of the brain where cancer has been growing. Ash paints the masks and personalizes them for each patient.

"I think it can make a huge difference," Ash told CTV Ottawa.

She spent 13 hours on her latest creation for nine-year-old Nicky Caldwell, who just finished his final treatment.

"I had headaches, throwing up. I didn't feel too good before I knew this was happening to me," he said. “You lay down, get it done. That’s all there is to it.”

Nicky’s mask reflects his love of sport and the Montreal Canadiens.

"I thought it was going to be just logos,” Caldwell added. “She surprised me with portraits, I'm really happy about that."

Ash dabbled in art before becoming a radiation therapist at a cancer treatment centre for adults. Her handiwork with masks allows her to combine the two.

"I can't just throw the paint brushes away and say ‘sorry kids, this takes 15 hours of my weekend’, I can’t,” she said. “Pediatric kids, they shouldn't be here."

With a report from CTV Ottawa’s Terry Marcotte

This story has been updated to correct the spelling of Gerry Ash's name and her job title