Handheld device could spot tumour tissue during surgery

A handheld device can distinguish between tumour and healthy tissue in lab tests, according to new research.

Its inventors, from the University of Texas in the US, believe the device could one day be used by surgeons to quickly identify cancer tissue, and in some cases the molecular makeup of a tumour, during surgery.

The results, published in the journal Science Translational Medicine, come from samples of patients’ tumours tested in the lab and from surgery on a small number of mice.

Experts said further development was needed, but the device – called the MasSpec Pen – could speed up certain surgical procedures in the future and, if needed, could diagnose characteristics of some cancers on the operating table. 

The device could also guide surgeons by helping them see if they’ve removed all of the tumour.

“If you talk to cancer patients after surgery, one of the first things many will say is: ‘I hope the surgeon got all the cancer out’,” said assistant Professor Livia Schiavinato Eberlin, who designed and led the study.

Schiavinato Eberlin hopes that the new tool could “improve the odds that surgeons really do remove every last trace of cancer during surgery.”

Researchers tested the pen in the lab on human and mouse tissue samples that contained healthy and cancerous cells. When pressed on different parts of the samples the pen recognised the difference between the cancer cells and normal cells, such as connective tissue.

The team then used the MasSpec Pen to help guide surgery on 3 mice with breast cancer. The device correctly identified where the cancer cells stopped and healthy tissue began.

Dr Emma King, a Cancer Research UK-funded surgeon, thinks that if further developed, the technology could “help surgeons decide the best approach for removing the tumour”.

In particular cases, surgeons need to know the makeup of the tumour being operated on quickly to determine if it’s benign or cancerous. The team believe the MasSpec Pen could also help surgeons make this call.

Samples tested during surgery can take over half an hour to prepare, meaning patients are under aesthetic for long periods of time or wait weeks for results.

Long surgeries increase the risk of infection and often have unwanted side effects from anaesthetic, as well as potential anxiety waiting for test results.

The US research team claim the MasSpecPen can identify cancerous tissues and some cancer types in only 10 seconds.

To see if the pen could identify the tumour type, they tested 253 patient tumour samples in the lab. The samples included normal and cancerous tissue from the breast, lung, thyroid and ovary.

They used this information to build a molecular database containing key molecular fingerprints for each of these cancers.

After comparing results from a pathology lab, the researchers say the pen predicted the tumour type correctly more than 96% of the time.

King said this was an exciting technology that “after development in clinical trials, might be able to help surgeons diagnose cancer during surgery.”

How the pen works:

• The device is pressed against the area of tissue and a drop of water is released.
• Small molecules made by the tissue seep into the water droplet, which is then sucked into a machine called a mass spectrometer.
• A mass spectrometer pulls apart the composition of these molecules. Different cancers have different combinations or amounts of these molecules, as do healthy cells.
• This unique molecular profile of the tissue is then compared to a database.
• The words “normal” or “cancer” appear on a computer screen.

This particular technology is in its early stages, but other devices which work in a similar way are already being tested in clinical trials.

Professor Zoltan Takats, a Cancer Research UK-funded scientist at Imperial College London, is the inventor of the iKnife, an intelligent surgical knife that can tell the difference between normal cells and tumour cells while cutting the tissue.

He says that unlike the iKnife, where the technology fits in the surgeons knife, the MasSpec Pen may be used alongside other surgical tools. But he says more development is needed before the device will be able to tell surgeons where the margin of the tumour lies in enough detail.

The MasSpec Pen team hope to start human trials next years to see if this technology could be of benefit to patients.