An 'intelligent' knife developed and tested by Imperial College London researchers enables real-time tissue analysis during cancer surgeries.
Surgeons have previously had to rely on visual clues or scans and images to distinguish cancerous tissue from healthy tissue, and it is often impossible to tell without histological testing, which takes at least 30 minutes. This time is spent with the patient still open in the operating theatre; even then the limited time means that results are based on a limited number of samples, thus comprising their reliability.
By combining mass spectroscopy – an extremely accurate and swift method of chemical analysis – with electrosurgery, Hungarian scientist Zoltan Takats has developed a tool that will vastly improve the procedure.
Mass spectroscopy is a method that enables weighing individual molecules represented in the sample and produces spectra of chemical elements comprising the studied material. By looking at individual molecules, it can thus spot even the tiniest amount of a chemical substance. However, conventionally, the method relies on rather power-hungry and voluminous technology.
Dr Takats built a smaller mass spectrometer and connected it to a tool with which surgeons are very familiar: an electrosurgical knife. Electrosurgical knives, having been around since the 1920s, are used to cut tissue using electric current. The tissue is cut by vaporising, which minimises blood loss.
Usually, the smoke created when the tissue is burned is simply sucked away, but the iKnife channels the smoke into a mass spectrometer. The chemical composition is analysed and results are made available on a computer screen in a matter of seconds. The surgeon therefore knows exactly whether or not the tissue he or she is about to cut contains any cancerous cells.
“So far, surgeons have been using methodology that was developed in the 19th century,” said James Kinross, lecturer at the Imperial College London, who has tested the iKnife. “But this methodology was developed without the modern knowledge of biochemistry, that has been accumulated in the past decades.”
Despite major advances in pharmacology and radiotherapy, surgery remains the main method of treating all major types of cancer. To make sure no cancerous cells are left behind, surgeons tend to cut out larger chunks of the tissue, making it more difficult for the body to recover. In spite of that, many patients have to be operated on again as the tumour grows back if some cells have not been removed.
“There is a real need for a technology that can help the surgeon determine which tissue to cut out and which to leave in,” said Lord Darzi, professor of surgery at Imperial College London. “This study shows that the iKnife has the potential to do this and the impact on cancer surgery can be enormous.”
To ‘teach’ the mass-spectroscope to recognise the affected tissue, the team collected and analysed samples of 302 patients. Characteristics of thousands of cancerous and non-cancerous cells including brain, lung, breast, stomach, and colon and liver tumours were recorded into the library to serve as a basis for the diagnostics.
The technology was then transferred to the operating theatre to perform real-time analysis. Samples of 91 patients were analysed using the iKnife with 100 per cent accuracy.
“We believe it will be a real game-changer in tumour resection surgery,” said iKnife’s godfather Zoltan Takats.
The results of the latest study conducted at Imperial College London have been published in the journal Science Traditional Medicine.
Takats firmly believes cancer is not the only application for iKnife, as it can be similarly taught to recognise bacterial infections or spot inadequate blood supply. James Kinross said the technology can also be expanded to involve iEndoscopes or iLaparoscopes.