Scalpel will be able to "sniff out" tumors
Scientists at Justus-Liebig University (Giessen, Germany), working under the guidance of Professor Zoltan Takats, have developed a new device that will help oncological surgeons to remove malignant tumors as cleanly as possible.
The device is a mass spectrometer connected to an electroscalpel and identifies the molecular profile of the tissues being cut during the operation. The developers have demonstrated that this approach makes it possible to differentiate not only different types of tissues, but also to distinguish malignant tumors.
When removing malignant tumors, surgeons often have to make difficult decisions without leaving the operating table. The new device is designed so that they do not have to determine the boundaries of the tumor at random. This will avoid excision of healthy tissues surrounding the tumor for reinsurance and more carefully remove cancer cells, which will reduce the likelihood of recurrence of the disease.
Mass spectrometry, a method that allows the identification of molecules with a high degree of accuracy by analyzing the ratio of their mass and charge, is already being used by several research groups to study biological materials. Scientists have long known that the molecular profiles of tumor and healthy tissues differ significantly from each other and their decoding allows not only to distinguish the affected tissue from healthy, but also to determine the degree of malignancy of a particular tumor.
Quite successful attempts to analyze biopsy samples using mass spectrometry have been made before, but moving this procedure to the operating room was problematic due to the complexity of sample preparation. Before the analysis, the molecules must be ionized and delivered inside the device in this form. Usually, to ionize a sample, it is bombarded with a stream of charged particles, which is completely inappropriate in the operating room.
Professor Takach drew attention to the fact that the by-product of some surgical instruments, including electroscalpels, are gaseous ions suitable for analysis using mass spectrometry. In addition, these fumes, the so-called "surgical smoke", are harmful to health, and during the operation they are removed with a pump.
As a result of the research, it was possible to demonstrate that mass spectrometry of surgical smoke allows obtaining a molecular map of tissues in real time. After the vapors enter the mass spectrometer (through the tube in the lower left corner of the instrument panel), the compounds contained in them are analyzed and compared with the database entered into the device, after which the surgeon receives a ready answer. Collecting and analyzing a sample takes only a few hundred milliseconds.
In addition to mass spectrometry, a number of other methods are being considered for suitability for use during surgery. One possible approach is to introduce fluorescent dyes to the patient that bind to molecules characteristic of tumor cells and visible in infrared light. However, mass spectrometry provides more detailed information about the molecular profiles of the tumor and surrounding tissues. The new system not only provides the surgeon with real-time information, it also allows you to get a "chemical" image of the tumor, which can be useful when prescribing postoperative treatment. For example, identifying a particularly aggressive type of tumor will help oncologists in choosing the most effective drug.
Graham Cooks, a professor of chemistry at Purdue University (Michigan), is also working on creating a system for analyzing tissues based on mass spectrometry. The functioning of its system, called DESI, requires spraying aerosols of charged particles onto the fabric. Technically, this approach is much more complex, however, it allows analyzing a wider range of molecules and obtaining more detailed information, whereas the Takacha technique identifies mainly lipids of the cell membrane.
German scientists have already tested their system on several animal species, including rodents with malignant tumors. They are also working with veterinarians who are going to use the device to remove spontaneously occurring cancerous tumors in dogs. Next month, the developers have planned the start of clinical trials of the device, while Professor Takach is already negotiating its industrial production with the German company Meyer-Haake, specializing in the production of electrosurgical equipment.
The biggest problem for the introduction of innovations into practice today remains its high cost. An electrosurgical unit costs an average of $8000, while the cost of a system for mass spectrometric analysis starts from $120,000. However, Takats notes that the modern market for mass spectrometric equipment is very limited, and the opening of an adjacent surgical market may cause a decrease in prices. He also hopes to reduce the cost of the system to about $ 20,000 by using equipment that allows the analysis of biological material, but is unsuitable for very high-precision work in a chemical laboratory.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Technology Review: Surgical Scalpel Sniffs Out Cancer.
21.10.2009