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2The 30th International Conference on Advanced Laser Technologies B-I-40
ALT'23
Optical visualization of biotissue microstructure and microvasculature in norm, pathology and after treatment
Potapov A.L.1, Moiseev A.A.2, Sedova E.S.3, Gamayunov S.V.3, Radenska-Lopovok S.G.4,
Gladkova N.D.1, Sirotkina M.A.1
1-Privolzhsky Research Medical University, 603950 - Nizhny Novgorod, Russia 2- Institute of Applied Physics of the Russian Academy of Sciences, 603950 - Nizhny Novgorod, Russia 3- Nizhny Novgorod Regional Oncologic Hospital, 603126 - Nizhny Novgorod, Russia 4- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119991 - Moscow, Russia
sirotkina_m@mail.ru
Multimodal optical coherence tomography (OCT) is a modern biological tissues imaging method. OCT allows studying the structure, functional state, mechanical and optical properties of biological tissues. OCT technology can be used in routine clinical practice in neurosurgery, oncology, abdominal surgery, gynecology and other medical fields. OCT is a non-invasive real time and label free imaging that provides 3D images of subsurface tissues with a spatial resolution of 10-20 ^m at a depth of 1-2 mm.
The multimodal OCT with the assessment of microstructure and microcirculation was used to diagnose and control photodynamic therapy of vulvar lichen sclerosus. Original algorithms for quantitative processing of OCT parameters were applied.
Unconditional OCT signs of normal vulva were formulated. At an early stage of lichen sclerosus, no changes were found in the connective tissue, but the number of blood and lymphatic vessels changed slightly. The severe stage of lichen sclerosus is characterized by the formation of sclerosis and hyalinosis of collagen fibers, which is manifested on OCT images by the absence of lymphatic vessels, a decrease in the number of blood vessels, and a change in their architectonics. A decrease in the density of the network of lymphatic vessels in the upper layer of the dermis was revealed at an early stage in the development of lichen sclerosus, which indicates that changes begin to develop directly under the epithelium. At a severe stage in the development of lichen sclerosus, the density of both the blood vessels and lymphatic vessels networks decreased to almost zero values in all layers of the dermis.
The restoration of the microstructure and microcirculation in the vulvar tissue for a period of 1-3 months after photodynamic therapy is shown to be almost to the level of normal tissue. This was accompanied by the absence of clinical manifestations of the disease and symptoms. In the case of partial recovery of vulvar parameters for a period of 3 months, all patients had a recurrence at 6 months after PDT.
This work was supported by the Russian Science Foundation grant 19-75-10084.
