|A demonstration of how the iKnife could be used in surgery|
Almost one in three operations to remove breast cancers fails to remove all traces of the tumour. It's a reminder of how difficult it is to excise cancers, when surgeons are heavily reliant on medical imaging and other information gathered in advance of the operation.
Professor Zoltan Takats of Imperial College, London, said trying to extract cancerous tissue can be like driving with your eyes shut.
"At the moment the information available for surgeons is not direct information. It is coming from the preoperative tasks. They can never be sure what is really being dissected," said professor Takats.
His answer to the problem is the iKnife - a surgical device that tells the surgeon whether the tissue they are removing is cancerous.
The iKnife is an electroknife, a probe which burns through tissue using an electric charge. Electroknives have been in use since the 1920s, but what the iKnife does is find a way to extract useful information from the vapour given off from the seared flesh.
Instead of just drawing this smoke away it is fed into a mass spectrometer, which is able to analyse the chemical composition of the vapour. By comparing the chemical signature of the smoke to that from thousands of cancerous and non-cancerous tissues from throughout the body the iKnife is able to indicate the type of tissue that is being cut - typically within less than two seconds. The instrument has a touchscreen monitor that shows the results of its analysis and can also feed information to the surgeon via an audio signal.
With early testing proving the instrument can accurately identify tissue types in surgical environments, the team are now working on designing a medical-grade mass spectrometer that can be used in an operating theatre.
Takats said clinical trials should show the iKnife is capable of removing more of the cancerous tissue than existing electroknife procedures, as well as reducing damage to healthy flesh near the site of tumours.
"It will surely decrease the reoperation rate but I don't know if it will decrease the reoperation rate by 10 percent, 30 percent or 90 percent," he said.
The benefits of removing more of the cancerous tissue are, as Takats points out, rather obvious, such as reducing the chance of tumours growing back.
"In case of breast cancer in 30 percent of cases there is tumour tissue left behind, which would grow into a new tumour," he said.
"It's very simple, you don't want cancer to stay in the patient, likewise you don't want too much healthy tissue removed," giving the example of neurosurgery, where he said damaging healthy tissue near the tumour could result in the patient "losing the ability to live a normal life".
Takats expects that randomised physical trials of the iKnife will be ready to start by the beginning of 2016.