Mass spectrometry imaging ‘to speed cancer diagnosis’

A new method for analysing biological samples based on their chemical makeup has the potential to change the way medical scientists examine diseased tissue, claim researchers at Imperial College London.

When tests are carried out on a patient’s tissue today, such as to look for cancer, the test has to be interpreted by a histology specialist and can take weeks to obtain a full result.

Mass spectrometry imaging (MSI) uses technologies that reveal how chemical components are distributed in a tissue sample. Scientists have proposed using MSI to identify tissue types, but until now no method has been devised to apply the technology to any type of tissue.

In Proceedings of the National Academy of Sciences, researchers at Imperial College London have outlined a method for processing MSI data and building a database of tissue types.

In MSI, a beam moves across the surface of a sample, producing a pixelated image. Each pixel contains data on chemicals present in that part of the sample. By analysing many samples and comparing them to the results of traditional histological analysis, a computer can learn to identify different types of tissue.

A single test taking a few hours can provide much more detailed information than standard histological tests. It would indicate if a tissue is cancerous, plus the type and sub-type of cancer, which can be important for choosing the best treatment. According to Imperial, the technology can also be applied in research to offer new insights into cancer biology.

In a statement, Dr Kirill Veselkov, corresponding author of the study from the Department of Surgery and Cancer at Imperial College London, said: ‘This work overcomes some of the obstacles to translating MSI’s potential into the clinic. It’s the first step towards creating the next generation of fully automated histological analysis.’

Dr Zoltan Takats, from the Department of Surgery and Cancer at Imperial College London, said: ‘This technology can change the fundamental paradigm of histology. Instead of defining tissue types by their structure, we can define them by their chemical composition. This method is independent of the user – it’s based on numerical data, rather than a specialist’s eyes – and it can tell you much more in one test than histology can show in many tests.’

It is claimed the technology will also be useful in drug development. To study where a new drug is absorbed in the body, pharmaceutical scientists attach a radioactive label to the drug molecule, then look at where the radiation can be detected in a laboratory animal. If the label is detached when the drug is processed in the body, it is impossible to determine how and where the drug has been metabolised. MSI would allow researchers to look for the drug and any metabolic products in the body, without using radioactive labels.

The research was funded by Imperial College London’s Junior Research Fellowship scheme, awarded to Dr Kirill A. Veselkov; the National Institute for Health Research Imperial Biomedical Research Centre and the European Research Council.