Children with cancer will be spared unnecessarily aggressive treatments thanks to a new scan that can predict how rapidly tumours will grow, doctors say.

The test has been hailed as a major advance towards being able to tailor treatments for brain cancer to the needs of individual patients and is predicted to improve survival rates.

“This is a huge step forwards towards the introduction of more personalised treatment for childhood brain tumour patients,” said Prof Andrew Peet, a paediatric oncologist at the University of Birmingham and Birmingham Children’s Hospital, who led the work. “Assessing how aggressive these tumours are at an earlier stage will help ensure that treatment is no more toxic than it needs to be, reducing the adverse effects on patients and improving their quality of life.”

While survival rates have steadily improved for childhood brain tumours, with 75% of patients now living beyond five years, accurately predicting how the disease will progress in individual patients has remained a challenge. The need to tailor treatments is particularly acute in children, who are the most vulnerable to the side-effects of radiation and toxic drugs, Peet said. Childhood brain cancers currently account for one third of all childhood cancer deaths in the UK.

The Birmingham team took biopsies of childhood brain tumours from 114 patients who had been treated at the hospital and their outcomes were tracked over five years. By the end of the study, 79 were alive and 35 had died. The analysis found that the levels of fats, called lipids, and another chemical called glutamine, were direct indicators of how aggressive a tumour would be. The more glutamine a tumour contains, the less aggressive it is likely to be; the more lipids a tumour contains, the more aggressive it is likely to be.

The study, published in the journal Scientific Reports, also found that an MRI scan, designed to pick up chemical signatures of the tumour, could be used to accurately measure the concentrations of glutamine and lipids. “This type of refinement will help children get better treatment,” said Peet.

Poppy Guilder, 16, from Tamworth was one of the children who participated in the trial. She was diagnosed with a brain tumour when she was only 14 months old after her GP noticed she had a slight squint in one eye. “They found a huge mass the size of an orange,” her mother, Lisa Guilder, recalled.

After surgery to remove the tumour, a biopsy suggested that the tumour was benign. “They said hopefully that’ll be the end of the treatment,” Lisa said. However, the tumour was far more aggressive than expected and grew back within seven weeks.

“Her tumour 100% did not behave how we thought it was going to,” said Peet, who has been involved in Poppy’s treatment ever since. “The quality of information at that time was poor. If we’d known these things back when we started treating her it would’ve been so useful.”

After intensive treatment and multiple surgeries during her childhood, Poppy’s tumour is now stable. This summer she took her GCSEs and is now studying health and social care at college and in her spare time teaches swimming and dances. However, some of the children treated alongside Poppy have not had such positive outcomes, with some dying from side-effects linked to their treatment. Lisa hopes the new scan will help the next generation of children get the right treatment.

Mark Brider, CEO of Children with Cancer UK, which funded the study, said: “Childhood cancers are very different to those found in adults, they are often more difficult to treat and the treatment can be incredibly debilitating. Brain tumours are among the most common childhood tumours and I am very pleased to see developments being made to make treatment less toxic.”

Ian Walker, Cancer Research UK’s director of clinical research, said: “This important research shows that looking at the molecules produced by cancer cells’ metabolism could offer a promising new way to predict how well some children with brain tumours might respond to treatment or whether their cancer is likely to come back.

“We urgently need a better understanding of these hard-to-treat tumours so that doctors can consider prescribing additional treatments or enrolling children in clinical trials of new treatments earlier on, giving them the best chance of survival.”