Text: From: http://www.informnauka.ru/eng/ Physicians employ all available remedies to fight the sinister disease of the 20th century and apparently of the 21th century. Furthermore, physicians are in continuos search of new drugs. To curb the cells of the organism which get out of control, multiply infinitely and kill their proprietor, the cells are exposed to hard gamma rays, get poisoned with knock-out doses of toxic substances, the researchers are trying to deprive the cells of nutrition and provoke them to suicide. However, there is one more opportunity - it has turned out that the light is pernicious to the cancerous growth cells under certain conditions. Having joined the effort, physicians and physicists are improving a new approach to the cancer treatment - fluorescence diagnostics (FD) together with photodynamic therapy (PDT). The light helps physicians of the Gertsen Moscow Scientific Research Oncological Institute to fight cancer. The division headed by Professor Sokolov closely collaborates with the department of optical spectroscopy, Prokhorov Institute of General Physics, Russian Academy of Sciences, headed by Professor Smirnov, Doctor of Science (Physics&Mathematics). In 2002, their joint research was supported by the Russian Academy of Sciences in the framework of the "Abstract Sciences - to Medicine" program. The objective of diagnostics is to make the tumour visible, to this end the tumour should be irradiated by the source of light (laser) of a certain wave-length. Every cell of the organism contains the substances called fluorochroms, which become luminescent when exposed to external irradiation. Healthy and malignant tissues luminesce differently, and this is how the previously invisible tumour gives itself away. For this purpose photosensitizer medications can help, as they (this is important1) get selectively accumulated in the tumour tissues. In response to laser emission, the tumour will fluoresce predominantly. And ultimately, some substances can be introduced to provoke fluorochroms formation in the malignant tissues, and then their fluorescence can be observed. Not only does laser make the tumour visible, but it also kills it. The photosensitizer accumulated in the malignant tissue absorbs the light quantum when exposed to laser emission and transfers the energy to the atom of oxygen which makes part of photosensitizer. The atom of oxygen gets excited and becomes a strong oxidant - it damages membranes, microbodies and oxidizes vitally important molecules in malignant cells. Necrosis develops and the tumour gets killed. The physicists have developed and physicians successfully apply the laser diagnostic system, which allows to perform radiation spectrum analysis of each point of the tumour and to simultaneously observe its outline on the screen. Few specialists all over the world combine these methods, the majority does not go beyond the fluorescence image. "We developed the first device for the Gertsen Moscow Scientific Research Oncological Institute in 1992, says Natalia Bulgakova, senior research assistant, Prokhorov Institute of General Physics, Russian Academy of Sciences. - It worked with the national photosensitizer called photogem. Then appeared photosens, which is now undergoing the last phase of clinical trials. Both medications cope well with their task, but they cause an annoying by-action: the patients react oversensitively to direct sunlight, and therefore, they have to stay at home for 4-6 weeks. The medication of the last generation - alasense - is deprived of this disadvantage. Like photosens, alasense was developed by the State Scientific Center - Scientific Research Institute of Optical Intermediate Products and Dyestuff". .Professor Sokolov describes the utilization of laser units by oncologists: "A cancerous growth, as a rule, begins to develop in the surface layers of the skin and mucous membrane of internal. Such surface tumour is an ideal target for the laser. With the help of fluorescence diagnostics, we can see the tumour at the very early stage and start the treatment. We succeed to completely annihilate small tumours (their size varying from 2 millimeters to 2-3 centimeters) or multiple surface foci". The main advantage of the treatment by light is its selectivity. As photosensitizer is accumulated in the tumour, the surrounding tissues remain intact. Therefore, as compared to radiotherapy and chemotherapy, photodynamic therapy is almost innocuous to patients. Moreover, it has turned out that the photodynamic effect also stimulates the immune system, which is important for the cancer patients. That is why the photodynamic treatment can be repeated several times if one treatment is insufficient. On top of that, the method is inexpensive. With support from the Moscow Government and city administration, the fluorescence diagnostics and photodynamic therapy methods are already applied at hospitals # 6, 11, 40 and 62, Sechenov Moscow Medical Academy, Russian Oncological Scientific Center, municipal oncologic dispensary?, and also in town of Vladimir, Tula, Novomoskovsk, Novosibirsk, Chelyabinsk, Obninsk and St. Petersburg. Russian devices are already used in Brazil and South Korea, and foreign physicians come over to visit Moscow oncologists to adopt their experience.

See Also: BIOPHOTONIC THERAPY

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