Cancer surgery
iKnife allows surgeons to tell the difference between healthy and cancerous tissue (Reuters)

An 'intelligent knife' has been created to tell the difference between cancerous tissues and healthy ones.

The 'iKnife', developed by researchers at Imperial College London, was 100% accurate in detecting tumours in samples from 91 patients in just three minutes - at present, this information takes up to half an hour to obtain from laboratory tests.

Surgery is normally the best treatment option for patients who have cancer with a solid tumour. However, it is impossible to tell the difference between healthy and cancerous tissues so, even though surgeons take out extra healthy tissue, cancer cells are often left behind.

A fifth of breast cancer patients who have surgery need a second operation because some of the cancer is left over.

Lord Darzi, co-author of the study, said: "In cancer surgery, you want to take out as little healthy tissue as possible, but you have to ensure that you remove all of the cancer. There is a real need for technology that can help the surgeon determine which tissue to cut out and which to leave in.

"This study shows that the iKnife has the potential to do this, and the impact on cancer surgery could be enormous."

The iKnife was uses an electrical current to rapidly heat tissue, cutting through flesh while minimising blood loss. This technology was invented in the 1920s and is commonly used in hospitals today.

Reference library

During surgery, the tissue is vaporised and the smoke produced is removed with extraction systems. If surgeons are uncertain about the tissue they are removing, they send the tissue samples to be tested during the operation, while the patient is still under general anaesthetic.

Zoltan Takats, inventor of the iKnife, recognised that the smoke would provide a wealth of biological information - including whether the tissue was cancerous or not.

To create the iKnife, he connected an electrosurgical knife to an analytical instrument that can identify which chemicals are present in a given sample.

Researchers analysed the tissue samples of 302 cancer patients to record characteristics of healthy and cancerous tissues from lung, brain, breast, stomach, colon and liver tumours.

This was then used as a reference library to match readings during surgery to different types of tissues, giving results in less than three minutes. In surgery tests, the iKnife was 100% accurate.

The team now plans to try out the iKnife in a clinical trial to see if it helps boost patients' outcomes.

Takats said: "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 tumour recurrence rates and enable more patients to survive."