Katja[a]
BBC News 14.11.04
Brain tumour detection advances
Accurate diagnosis aids treatment
It is becoming possible to diagnose brain tumours with greater accuracy thanks to transatlantic discoveries.
US scientists at Duke University have found a way to distinguish between abscesses and brain tumours without the need for surgery using scans.
UK researchers at Birmingham University are using scans to tell the type of tumour and predict how it might respond to treatment.
Both are based on a traditional scanning method called MRI.
We are starting to be able to move from being able to look at things to being able to find out what they are and what they do.
Dr Andrew Peet, head of the Birmingham research
Regular magnetic resonance imaging scans show the size and shape of structures in the brain.
But it can be difficult to tell what different structures are made up of and how they function with these scans.
The US and UK teams looked at ways to overcome these shortfalls.
The Duke University team used a process called dynamic susceptibility contrast (DSC) MRI to help doctors distinguish between collections of puss in the brain called abscesses and cancerous growths.
DSC MRI measures blood volume. In this way it is possible to spot the more vascular tumours from abscesses which do not have such a big blood supply.
Lead researcher Dr James Provenzale said: "The distinction between abscess and tumour can be made by surgically removing the tissue from the brain, but one would rather make the diagnosis by a non-invasive measure.
"The treatment for the two are also different - antibiotics for abscesses and surgical removal, chemotherapy or radiation therapy for tumours.
Honing in
"A worst-case scenario would be one in which the wrong treatment is given for weeks or months due to a misdiagnosis."
In a study on eight patients - four with tumours and four with abscesses - DSC MRI correctly distinguished between the two brain problems.
Although larger trials are needed, the findings are promising, the authors told the American Journal of Roentgenology.
Meanwhile, UK researchers have been using nuclear magnetic resonance (NMR) spectroscopy, in addition to conventional MRI scans, to more accurately diagnose children´s brain tumours.
NMR spectroscopy gives the doctors a better idea of what type of tumour they are dealing with - whether it is likely to be aggressive or a well behaved, more harmless one for example.
Dr Andrew Peet, from Birmingham Children´s Hospital in the UK where the technique is being trialled, said: "With conventional MRI its very difficult to tell the difference between one tumour and another.
"NMR looks at the chemicals within the tissues. These chemicals give us a fingerprint which is characteristic of certain tumours.
Tailoring treatment
"This will tell us what type of tumour this is and how well it might respond to treatment. Plus, you can carry it out at the same time as conventional imaging so you get this information almost for free."
He said they, along with colleagues at the Royal Marsden and Queens Medical Centre in Nottingham, were gradually building up a database of tumour fingerprints that should help doctors to better distinguish between tumours, particularly rarer tumours.
To do this they are scanning tumour samples removed from children with a more powerful NMR scanner.
Eventually, they hope it will be possible to routinely scan children diagnosed with a brain tumour using NMR.
Dr Peet said this might save some children unnecessary surgery.
"In some children, the tumour can be removed entirely and the patient can be cured by a technique other than surgery - with chemotherapy for example.
"With some tumours it is more important to get the whole tumour out with surgery than it is with others. Sometimes you can just leave it if it is a low grade tumour and it will not do anything.
"So knowing what the tumour is beforehand is helpful."
Speaking about the US research he said it would be interesting to find out whether different brain tumours had different blood volume patterns.
"There is some evidence that tumours that have a greater blood supply are different from ones that don´t and we have drugs that can act on the blood supply now.
"All of these techniques are us trying to get more out of MRI scans.
"Over the next decade we will see a whole new range of tools in our box for imaging that will give us more and more information on what tissues are.
"It´s very exciting because we are starting to be able to move from being able to look at things to being able to find out what they are and what they do."