Dr. Zoltan Takats of the Imperial College London has developed one very sharp knife – and we're not referring to its keen edge. The Intelligent Knife (iKnife) is equipped with a nose and a brain that can sniff out cancer as it cuts. Using a mass spectrometer to detect chemical profiles associated with tumors, it enables instant identification of cancerous tissue and helps surgeons to make sure that all of a tumor has been removed.
Cancer is obviously something you want to catch early and get rid of completely at the first opportunity. Removing tumors is the simplest and often the least harmful way, but surgeons need to ensure they've removed all of the cancerous tissue to prevent the disease from reestablishing itself.
Unfortunately, cancerous tissue isn't always obvious by sight and laboratory tests are needed. During an operation, this means leaving the patient waiting under anesthetic while the tests are run. Even then, the results aren't always reliable. According to Imperial College, one in five breast cancer patients must undergo surgery a second time.
The iKnife uses electrosurgery; a common technique developed in the 1920s designed to reduce bleeding in particularly bloody operations, such as liver resectioning. The knife is subjected to an electric current, which heats tissue so fast and at such a temperature that the knife cuts through and cauterizes the tissue to prevent bleeding. Not surprisingly, this produces a cloud of unpleasant smoke, which is sucked away.
However, this cloud also contains all sorts of useful information about the tissue being burned through, so Takats hit on the idea of hooking an electrosurgical knife to a mass spectrometer, which would analyze the smoke and produce a profile of the chemicals that make it up. Some of these chemicals or their combinations are indicative of cancerous tissue.
Once the prototype iKnife was constructed, the next step was to teach it what to look for. This involved using the device to burn tissue samples collected from 302 surgery patients and building up a library of profiles of thousands of cancerous and noncancerous tissues from various organs of the body. As the iKnife cuts through tissue, it matches what it “smells” against this library and alerts the surgeon as to what it finds in about three seconds. This is a considerable improvement over the half hour needed for conventional laboratory tests.
The iKnife has been used in tests in 91 operations, where it showed 100 percent accuracy when compared to conventional tests. According to Imperial College, the next step will be clinical trials where the surgeons will be allowed to see the results in real time instead of after the operation, as was the case in the tests.
“These results provide compelling evidence that the iKnife can be applied in a wide range of cancer surgery procedures,” Dr Takats says. “It provides a result almost instantly, allowing surgeons to carry out procedures with a level of accuracy that hasn't been possible before. We believe it has the potential to reduce tumor recurrence rates and enable more patients to survive.”
Takats sees the iKnife as having broader applications beyond cancer surgery. Mass spectrometry is a rather general tool and Takat says that it could be used to identify tissues with inadequate blood supply, the presence of certain bacteria, and might even be of use to the local butcher in telling beef from horsemeat.
The results of the iKnife project were published in Science Translational Medicine.
The video below introduces the iKnife.