Russian specialists consider that one of the most effective and safest diagnostic methods for various types of cancer is the photodynamic therapy (PDT), which consists of the application of a photosensitizer (a substance that increases the sensitivity to light of biological tissues) that is injected into the blood. With this method, cancer cells are able to accumulate these substances in greater amounts compared to healthy cells. Within a period, when most of the photosensitizing substance has left the normal cells it still remains in the cancer cells and the tumor is exposed to laser light of a specific wavelength.
Even so, this method had a limitation and it was the lack of precision because, although it can easily detect where the malignant tumors are, it could not pinpoint exactly where they ended and this led to a relapse of the disease.
To solve this problem, MEPhI scientists created a unique endoscopic fluorescence video system that allows to visualize the accumulation of photosensitizer in areas of difficult access to treat brain and neck tumors.
The scientists explained that the uniqueness of this system is that it makes it possible to clearly define the limits of neoplasms in which the photosensitizer has accumulated, as well as to quantify its concentration in tissues during an operation.
“The precise definition of the tumor boundaries is a decisive factor for effective treatment. Intraoperative fluorescence diagnosis can achieve this, increasing the efficiency of FDT and increasing the median survival of patients with tumors of the head and neck. neck, “noted Professor Viktor Loshchenov.
Treatment of liver and colon cancer
One of the most difficult organs to treat with the FDT method is the liver because it retains an enormous amount of substances and this makes it difficult to correctly identify the pathological cells.
Thus, MEPhi specialists developed the quantitative evaluation method, which was initially tested in the hepatobiliary system of wild boars, to calculate the concentration of photosensitizers in the tissues of the bile ducts, allowing the diagnosis and treatment to be optimized with therapy. FDT.
Scientists have also found the unique laser endoscopic fluorescence video system in addition to FDT photodynamic therapy to show promise for effective colon cancer diagnosis. With this technique, the spectroscopic examination of the stomach mucosa makes it possible to determine the tumor at a depth of three or four millimeters, according to the MEPhi scientists, it is two times greater than that of similar techniques.
Clinical studies of new methods to treat these cancers were conducted at the Levshin Institute for Group Oncology at Sechenov University Hospital. These methods are currently actively applied in many clinics in Russia, the scientists concluded.