The scientists used the methods of fluorescence diagnostics (FD) and photodynamic therapy (PDT). They moistened a gauze swab with some photosensitizer and applied it to the neoplasm for 2-3 hours.
Abnormal cells are able to accumulate such substances in much larger quantities compared to healthy ones. When most of the photosensitizer leaves normal cells but remains in the abnormal ones, the affected area is exposed to combined radiation, consisting of short powerful light pulses and soft red LED light.
The photosensitiser absorbs radiation and activates molecular oxygen, dissolved in the body tissues. The oxygen goes from the triplet state to the singlet state, where it has strong oxidising properties; it then destroys the cells of the abnormal tissue and creates favourable conditions for immune response activation.
When the photosensitiser is excited, the light occurs, which is recorded using spectroscopic methods and helps to accurately determine the boundaries of the affected tissue.
"The PDT is an organ-preserving method of treating this disease; it has already proved its effectiveness, which is confirmed by positive results in more than 700 patients,” Victor Loschenov, the acting Head of the Department of Laser Micro-, Nano- and Biotechnologies of NRNU MEPhI, said.
According to him, the results of the approaches used indicate strong potential in utilising such promising technology to contribute to the possible prevention of malignant transformations and the treatment of leukokeratosis.
The scientists are currently improving the method, to create the optimal technology for evaluating laser exposure efficiency during the procedure for all irradiated areas simultaneously. This will help to change treatment tactics in a timely manner and avoid under-irradiation or overexposure, which could lead to relapse or necrosis. This is especially important when using the PDT technology for such dangerous diseases as cancer and precancerous cervix.
