Two Perth parents are defending their attempt to stop their six-year-old son from receiving chemotherapy treatment for a malignant brain tumour.

Angela Kiszko and Adrian Strachan say they want to pursue alternative treatments for their son’s medulloblastoma instead of “harsh” chemotherapy and radiotherapy prescribed by doctors.

He has already undergone a six-hour surgery.

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“I don’t want my son’s brain fried with radiation. The effects are too harsh, too damaging … I find it even difficult to call it a treatment,” Ms Kiszko told the Nine Network’s 60 Minutes.

The parents appeared on television after a Perth doctor took legal action that forced them to take six-year-old Oshin Kiszko to the hospital for cancer treatment.

The judge’s decision was based on medical evidence and the child’s best interests, the Australian Medical Association says.

Family Court Judge Stephen Thackray in March said “parental power was not unlimited” and found the parents were not acting in their child’s best interests because doctors believed he would die within a few months without treatment.

The court was told Oshin had a 30 per cent prospect of surviving for five years if chemotherapy started immediately and a 50 per cent chance with both chemotherapy and radiotherapy, but could die within months without it.

The parents contacted media outlets and are appealing the decision.

Ms Kiszko said it had been “horrific to watch” his first week of chemotherapy and even though it might save him, she preferred quality of life over quantity.

“I would not put myself through this,” she said.

“I want him to live. I don’t want him to survive.”

AMA national ethics chairman and WA president Michael Gannon has previously said he thought the doctor’s decision to legally challenge the parents was brave.

“It is very difficult to try to make a case to a parent that you think you know better than their wishes for their own child and put their head above the parapet,” he told ABC radio.

“There is no doubt at all about this decision being made based on significant prospects of a cure or, if not, significant prospects of a high quality of life for a meaningful period of time.”