Essential Science: Surgeons detect cancer using sound

Posted Nov 14, 2016 by Tim Sandle
Medical technologists have successfully deployed advanced technology based on sound that helps them to perform precise operations to remove tumors and to protect healthy tissue.
File photo: An operating theater.
File photo: An operating theater.
Brendan Smialowski, AFP/File
Cancer surgery is complex and the aim of the surgeon is to remove all cancerous tissue. This is not a straightforward task, and it can be difficult to determine the extent that cancerous tissue has spread. The result can be that some cancerous tissue remains. Such surgery also carries the risk of damaging or removing healthy tissue that surrounds the cancerous tissue.
To aid the surgeon, medical technologists have been developing next-generation surgical tools which fit in with the ‘smart’ technology paradigm. The aim is to help surgeons navigate through the body with greater accuracy, enabling them to perform precise surgery.
One device that has recently been developed is the iKnife. The iKnife heats tissue as it cuts to make a clean incision. Smoke generated from the tissue is ionized using Rapid Evaporative Ionisation Mass Spectrometry (REIMS) technology and subsequently analyzed using a mass spectrometer. This provides information about the chemical composition of the cells.
The technology behind the tool is based on a near-infrared laser probe. This probe captures the vibration frequencies of different tissues, enabling the surgeon to differentiate between cancerous and healthy tissue. The signal gives the surgeon an accurate location to begin making an incision.
The technology is based on Raman spectroscopy. This is a spectroscopic technique used to observe vibrational, rotational and other low-frequency modes. The process is more often associated with chemistry in order to provide a chemical ‘fingerprint’, which allows different molecules to be identified.
The early prototype sent information to a display screen. Where this proved distracting to the surgeon, a later development led to the inclusion of an audio signal. This allows the surgeon to focus directly on the procedure.
Discussing the technology with Laboratory Roots, one of the researchers behind the development, Dr. Matthew Baker, who works at the University of Strathclyde (U.K.) explained: “We’ve shown how to give accurate guidance to surgeons in a way that allows them to keep their focus on their scalpel. Looking back and forth between a screen and the patient is not ideal. It would be better if a surgeon’s focus could be in one place.”
At this stage the technology is still being tested; however, trials conducted in Canada have been, according to New Scientist, successful. With the trials, surgeons were able to detect differences with the audio frequency and use the sounds to differentiate between cells and tissue that was healthy compared with cancerous material. The accuracy from these trials is reported to be 70 percent.
While 70 percent represents an improvement there remains work to do and further upgrades to the technology are set to take place. The findings are published in the journal Analyst, with the research paper headed “Feature driven classification of Raman spectra for real-time spectral brain tumor diagnosis using sound.”
This article is part of Digital Journal's regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week we examined whether fungi became more pathogenic in space, and if this phenomenon posed a risk to astronauts. The previous week the topic of ‘open access’ and the publishing of scientific data was discussed, with a review of how more scientific data could be made available to researchers and the general public.