Surgical Scalpel Sniffs Out Cancer

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"This work represents a milestone in the application of mass spectrometry to medicine," says R. Graham Cooks, a professor of chemistry at Purdue University who was not involved with the research.

Mass spectrometry is just one of many imaging techniques being evaluated for use during surgery. Another approach is to inject a patient with fluorescent dyes that bind to tumor molecules and are visible under infrared light. But mass spectrometry can provide more comprehensive information about tissues' molecular profiles. The new system not only provides real-time information, but also produces an image of the tumor, using chemical information, which could also help guide postoperative care. The imager could, for example, reveal a particularly aggressive form of cancer, and this information could guide oncologists in prescribing the right drug.

Cooks is developing a different type of mass-spectrometry system for tissue analysis. His system, called DESI, requires spraying a mist of charged particles onto the tissue, but it can analyze a wider range of molecules and might provide more detailed information. Takáts's technique mostly samples the fatty molecules called lipids that make up cell membranes.

So far, the German researchers have tested the surgical mass-spectrometry system in several animals, including rodents, with cancer. The group is also working with veterinarians to use the scalpel during tumor-removal surgeries in dogs with naturally occurring tumors. Next month the device will go into human clinical trials, and Takáts is working with Meyer-Haake, a German electrosurgical device company, to develop the machinery.

The most important remaining hurdle to getting mass spectrometry into the operating room may be the expense. An electrosurgery system typically costs $8,000, while a commercial mass-spectrometry system starts at $120,000. Takáts notes that the market for mass spectrometry is currently very small, but opening up the surgical market may help bring costs down. By using instruments tailored to the kind of analysis relevant to biological tissue, which doesn't need to be as high-performance as that in chemistry labs, Takáts hopes to make a machine that costs about $20,000.