Scientists discover tissue differences in brain cancer in children
Pediatric low-grade gliomas usually softer than normal brain tissue: Study
U.S. scientists have discovered that pediatric low-grade gliomas — a type of brain cancer that can occur in children — are generally softer than normal brain tissue, according to a study said to be the first of its kind.
These newly identified mechanical differences may help distinguish between brain cancers and other types of abnormal brain tissue in children — and ultimately could lead to improvements in managing this type of rare cancer — the researchers said.
“While mechanical property analysis of … pediatric gliomas … is far from complete, this work provides an initial step in understanding how mechanical properties can be useful in [the] clinical or surgical management of pediatric brain tumors,” the team wrote.
The study, “Mechanical properties of pediatric low-grade gliomas in children with and without neurofibromatosis type 1,” was published in the journal Paediatric Neuroradiology.
Researchers launch first study of mechanisms in brain cancer in children
Pediatric low-grade gliomas, or LGGs, are a type of slow-growing tumors in the brain and spinal cord that occur in children. LGGs typically have a better prognosis than more aggressive brain tumors, and are primarily treated with surgery, which involves removing as much of the tumor as possible.
However, managing pediatric LGGs is difficult in large part because it’s hard to treat the cancer itself without also causing damage to the surrounding brain tissue, which can cause major problems in children and adolescents whose brains are still developing.
Neurofibromatosis type 1, or NF1, is a genetic disorder that can increase the risk of LGGs and other brain cancers. However, individuals with this condition also frequently have irregular spots of brain tissue called focal abnormal signal intensities, or FASIs. FASIs are not cancerous, but it can be hard to tell the difference between FASIs and cancer with traditional imaging techniques — especially when both FASIs and LGGs occur at the same time.
Now, a team of U.S. researchers examined LGGs and FASIs using a novel imaging technique called magnetic resonance elastography, or MRE, which is able to assess the stiffness of tissues inside the body.
“To date, no study has used MRE to noninvasively assess the mechanical properties of pediatric gliomas, and in general, LGGs have been mostly overlooked,” the scientists wrote.
Their study included MRE brain scans from 23 children, ages 4 to 17, of whom 17 had LGGs and seven had NF1 with FASIs; one child had both LGG and FASI co-occurring.
The results showed that, on average, LGGs were significantly softer than normal brain tissue, with an average stiffness difference of 10.9% This wasn’t an absolute rule – in fact, there were a few outliers with tumors that actually were stiffer than normal tissue – but it was the case for most of the patients.
Measuring tumor mechanical properties … has potential to aid in [the] prediction of biological behavior and inform management strategies for pediatric patients.
Tumor damping ratio, a measure of how quickly a tissue returns to its normal state after being disturbed, was also reduced compared with normal tissue, suggesting differences in the tumors’ structural or mechanical properties.
By contrast, FASIs tended to be a bit stiffer than normal brain tissue. Again, this wasn’t an absolute: Some FASIs were much softer than normal tissue. Nonetheless, the results illustrate that, in general, LGGs and FASIs have different mechanical properties, according to the researchers.
“We find that FASIs have significantly higher relative stiffness compared to gliomas,” the team wrote, adding that “FASIs appear as slightly stiffer [than] normal appearing reference tissue, unlike gliomas which are soft.”
The scientists noted that this was a fairly small study, so further research will be necessary to validate the findings. But the team wrote that “differentiating FASIs from healthy tissue, and from lesions likely to show … progression, can be the defining factor in developing a suitable tumor monitoring plan.”
Ultimately, these findings are a first step in better understanding the mechanical properties underlying brain cancer in children, according to the researchers.
“Measuring tumor mechanical properties … has potential to aid in [the] prediction of biological behavior and inform management strategies for pediatric patients,” the team concluded.
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