2019, Kustov, D. M., Makarov, V. I., Osipova, E. E., Savelieva, T. A., Grachev, P. V., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

© 2019 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved Due to the high recurrence rate after the glial brain tumor removal, methods of intraoperative navigation have a high relevance, providing the most complete removal of tumor tissues with maximum preservation of healthy ones. In this work a combined visualization method is proposed with an assessment of fluorescence and diffuse reflectance images. Fluorescence intensity of 5-ALA-induced protoporphyrin IX allows visualization of tumor cells, distribution of indocyanine green fluorescence helps to visualize the vascular system of the tumor, and parallel mapping of the degree of oxygenation demonstrate the hypoxic regions. The images were obtained in the near infrared range of the optical spectrum in order to maximize the optical probing depth in the window of biological transparency.

2020, Maklygina, Y. S., Skobeltsin, A. S., Savelieva, T. A., Pavlova, G. V., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

The brain has an exceptionally high requirement for energy metabolism, with glucose serving as the exclusive energy source. Cancers, including glioblastoma, have a high glucose uptake and rely on aerobic glycolysis for energy metabolism. The alternation of high-efficiency oxidative phosphorylation to a low-efficiency aerobic glycolysis pathway (Warburg effect) provides macromolecules for biosynthesis and proliferation. Current research indicates that the specific metabolism in the tumor tissue and normal brain tissue in the glioma allows the use of 5-aminolevulinic acid (5 ALA)-induced protoporphyrin IX (PpIX) and methylene blue (MB) to monitor and correct the development of the tumor. The focus is on the detection of the differences between tumor cells and tumor-associated macrophages/microglia using spectroscopic and microscopic methods, based on the fluorescent signals and the difference in the drug accumulation of photosensitizers (PSs). Since 5 ALA has long been used effectively in the clinic for fluorescent surgical navigation, it was employed as an agent to identify the localization of tumor tissue and study its composition, particularly tumor and immune cells (macrophages), which have also been shown to actively accumulate PpIX. However, since PpIX is photodynamically active, it can be considered effective as the main target of tumor tissue for further successful photodynamic therapy. MB was employed to visualize resident microglia, which is important for their activation/deactivation to prevent the reprogramming of the immune cells by the tumor. Thus, using two drugs, it is possible to prevent crosstalk between tumor cells and the immune cells of different geneses.

2020, Maklygina, Y. S., Romanishkin, I. D., Savelieva, T. A., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

Gliomas are one of the most common brain tumors occurring in children and adults. Gliomas are primary, diffusely infiltrating brain tumors. There are few effective therapies for these type of cancer, and patients with malignant glioma fare poorly, even after aggressive surgery, chemo- and radiotherapy.

2020, Romanishkin, I. D., Bikmukhametova, L. R., Goryaynov, S. A., Kosyrkova, A. V., Savelieva, T. A., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

© 2020 Russian Photodynamic Association. All rights reserved.Neurosurgery of intracranial tumors, especially of glial origin, is a non-trivial task due to their infiltrative growth. In recent years, optical methods of intraoperative navigation have been actively used in neurosurgery. However, one of the most widely used approaches based on the selective accumulation of fluorescent contrast medium (5-ALA-induced protoporphyrin IX) by the tumor cannot be applied to a significant number of tumors due to its low accumulation. On the contrary, Raman spectroscopy, which allows analyzing the molecular composition of tissues while preserving all the advantages of the method of fluorescence spectroscopy, does not require the use of an exogenous dye and may become a method of choice when composing a system for intraoperative navigation or optical biopsy. This work presents the first results of using the principal component method to classify Raman spectra of human glioblastoma with intermediate processing of spectra to minimize possible errors from the fluorescence of both endogenous fluorophores and photosensitizers used in fluorescence navigation. As a result, differences were found in the principal component space, corresponding to tissue samples with microcystic components, extensive areas of necrosis, and foci of fresh hemorrhages. It is shown that this approach can serve as the basis for constructing a system for automatic intraoperative tissue classification based on the analysis of Raman spectra.

2019, Linkov, K. G., Meerovich, G. A., Akhlyustina, E. V., Savelieva, T. A., Loschenov, V. B., Меерович, Геннадий Александрович, Ахлюстина, Екатерина Витальевна, Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

© 2019 Russian Photodynamic Association. All Rights Reserved. Currently, the most promising method for the study of pharmacokinetics of drugs with fluorescent properties is the spectral-fluorescent method. In this article, we propose an algorithm for expanding the dynamic range of the spectrum analyzer by automatically monitoring the maximum spectral density in the recorded fluorescence spectrum and automatically controlled changes in the accumulation time depending on this value, followed by compensation of the output signal with regard to this change, as well as hardware circuit solutions that allow this algorithm. Testing of LESA-01-"Biospeс" spectrum analyzer, upgraded using the proposed approach, was carried out on photosensitizer dispersions based on tetra-3-phenylthiophthalocyanine hydroxyaluminium of various concentrations (from 0.01 mg/l to 50 mg/l), approximately corresponding to the concentrations realized in the process of studying pharmacokinetics in calibration samples and tissues of experimental animals. The proposed solutions that implement the algorithm for recording fluorescence spectra with automatic change of accumulation time depending on the signal level, ensured a significant expansion of the dynamic range of the spectrum analyzer (up to 3.5 orders of magnitude) and improved accuracy in pharmacokinetic studies.

2019, Kustov, D. M., Sharova, A. S., Makarov, V. I., Borodkin, A. V., Savelieva, T. A., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

© 2019 Astro Ltd.In this paper we consider a method for researching the dynamics of blood flow in the cerebral cortex, on an optical phantom that reproduces the parameters of real human and mice brain structures, through the use of near and infrared ranges of laser radiation. For the investigation of real tissue we chose a laboratory mouse brain in vivo. An algorithm for non-invasive diagnostics of the degree of oxygenation was identified and optimal parameters of installation components were selected for taking information about hemodynamic indicators. Output was verified by the reference method for assessing oxygenation by degree of absorption of hemoglobin in the visible range, which indicates that data have a high correlation with classical methods. With further development, this algorithm can be used in various areas of research and diagnostics.

2020, Savelieva, T. A., Kuryanova, M. N., Akhlyustina, E. V., Linkov, K. G., Meerovich, G. A., Loschenov, V. B., Савельева, Татьяна Александровна, Ахлюстина, Екатерина Витальевна, Меерович, Геннадий Александрович, Лощенов, Виктор Борисович

During intraoperative fluorescence navigation to remove various neoplasms and during pharmacokinetic studies of photosensitizers in laboratory animals, in many cases, the ratio of photosensitizer accumulation in the tumor and normal tissue can reach > 10-fold, which inevitably changes their optical properties. At the same time, the tumor formation process causes various metabolic and structural changes at cellular and tissue levels, which lead to changes in optical properties. A hardware-software complex for the spectral-fluorescence studies of the content of fluorochromes in biological tissues with significantly different optical properties was developed, and it was tested on optical phantoms with various concentrations of photosensitizers, absorbers, and scatterers. To correct the influence of optical properties on the photosensitizer concentration analysis by fluorescence spectroscopy, we propose the spectrum-processing algorithm, which combines empirical and theory-based approaches.

2019, Potapov, A. A., Chobulov, S. A., Nikitin, P. V., Okhlopkov, V. A., Savel'eva, T. A., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

5-ALA intraoperative fluorescence is widely used in surgery of brain tumors for intraoperative demarcation of boundaries and more total resection because 5-ALA metabolites are not accumulated in the intact brain and vascular tissues. Given this fact, it was hypothesized that fluorescence of vessels in the immediate vicinity of a brain tumor may indicate their infiltration by tumor cells as a potential pathway for their dissemination and as a factor for continued tumor growth after surgery and adjuvant therapy. PURPOSE: Identification of fluorescent vessels located near cerebral gliomas, with a histological description of their structure, relationships with the tumor, and potential invasion of the walls by tumor cells. MATERIAL AND METHODS: A prospective cohort study included 14 patients with malignant supratentorial gliomas, aged 20 to 78 years. Five patients were operated on due to continued tumor growth. Two hours before surgery, all patients received 5-ALA orally. During surgery, a microscope (Carl Zeiss OPMI Pentero, Germany) with a fluorescent module (BLUE-400) was used. In all cases, molecular-genetic and immunohistochemical examinations of the tumor material were performed. During surgery, fluorescent vessels, after evaluating their functional significance, were also resected for histological examination. RESULTS: Glioblastoma and anaplastic astrocytoma were verified in 10 and 4 patients, respectively. In 4 out of 10 glioblastoma cases, vessels with homogeneous or fragmentary fluorescent walls were detected in the tumor bed after resection of most of the tumor; in patients with anaplastic astrocytomas, vascular fluorescence was not observed. In the four vascular samples with intraoperatively detected wall fluorescence, tumor invasion into the vascular layers was revealed in all cases. These patients underwent an immunohistochemical examination with monoclonal antibodies to the glial GFAP marker, which clearly identified areas of ingrowth of tumor cells into the vascular wall. CONCLUSION: 5-ALA intraoperative fluorescence is a fundamentally new approach in the rapid diagnosis of tumor-infiltrated blood vessels. Invasion of tumor cells to intact vessels may be a mechanism of tumor progression and dissemination. Additional resection of fluorescent vessels may affect the radicalness of surgical treatment, but requires a mandatory assessment of their functional significance. Интраоперационная флуоресценция с использованием 5-аминолевулиновой кислоты (5-АЛК) широко используется в хирургии опухолей головного мозга с целью интраоперационной демаркации границ и увеличения радикальности удаления, поскольку накопление ее метаболита отсутствует в интактных тканях мозга и сосудов. С учетом этого факта высказана гипотеза о том, что флуоресценция сосудов, расположенных в непосредственной близости от опухолей мозга, может указывать на их инфильтрацию опухолевыми клетками как на потенциальный путь их диссеминации и фактор продолженного роста опухоли после операции и адъювантной терапии. Цель исследования - выявление флуоресцирующих сосудов, расположенных вблизи глиом головного мозга, с гистологическим описанием их структуры, взаимоотношений с опухолью и возможной инвазии стенок опухолевыми клетками. Материал и методы. В проспективное когортное исследование включены 14 пациентов в возрасте от 20 до 78 лет со злокачественными супратенториальными глиомами. У 5 больных операция проведена в связи с продолженным ростом опухоли. Все пациенты за 2 ч до операции получали 5-АЛК внутрь. Во время операции использовали микроскоп OPMI Pentero (Carl Zeiss Meditec AG, Германия) с флуоресцентным модулем (BLUE-400). Во всех случаях проведены молекулярно-генетическое и иммуногистохимическое исследования опухолевого материала. В ходе хирургического вмешательства дополнительно для гистологического исследования резецировали флуоресцирующие сосуды после оценки их функциональной значимости. Результаты. У 10 пациентов верифицирована глиобластома, у 4 - анапластическая астроцитома. В 4 из 10 наблюдений c глиобластомами после удаления основной массы опухоли в ложе удаленной опухоли выявлены сосуды с гомогенно или фрагментарно флуоресцирующими стенками, у пациентов с анапластическими астроцитомами флуоресценции сосудов не отмечалось. Во всех четырех образцах сосудов, в которых интраоперационно определена флуоресценция стенки, выявлена инвазия опухоли в васкулярные слои. У данных пациентов проведено иммуногистохимическое исследование с использованием моноклональных антител к глиальному маркеру GFAP. Это позволило четко выделить участки врастания опухолевых клеток в сосудистую стенку. Выводы. Интраоперационная флуоресценция с применением 5-АЛК является принципиально новым подходом в экспресс-диагностике сосудов, инфильтрированных опухолью. Инвазия опухолевыми клетками ранее интактных сосудов может являться механизмом, посредством которого осуществляются прогрессирование и диссеминация опухолевого процесса. Дополнительная резекция флуоресцирующих сосудов может влиять на радикальность хирургического лечения, однако необходима обязательная оценка их функциональной значимости.

2020, Loshchenov, M. V., Borodkin, A. V., Linkov, K. G., Kosyrkova, A. V., Savelieva, T. A., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

© 2020 SPIE.The new approach to intraoperative navigation during glial brain tumors removal is presented. A combined method is proposed for simultaneous spectroscopic and video fluorescence analysis of the state of tissues in the destruction zone using the applied part performed in the form of a neurosurgical aspirator cannula. In the walls of the applied part there are tubular channels into which lighting and receiving optical fibers are integrated. At the end of the cannula, the channels for optical fibers are arranged so as to perform spectroscopic analysis in contact with the surface of the biological tissue, as well as video fluorescence analysis at the working distance to the surface of the tissue. The joint use of fiber-optic systems for recording the video stream and spectral dependences allows real-time assessment of the degree of pathological tissue changes in the field of view of the video system, which are also located in the aspiration zone, with the simultaneous quantification of diagnostically significant spectroscopic criteria. System testing was carried out on samples of human intracranial tumors obtained during neurosurgical operations. During the removal of a tumor from different sites (tumor center, perifocal area), the degree of in vivo fluorescence signal from the tumor site was determined intraoperatively using a Zeiss Opmi Pentero intraoperative microscope in Blue 400 mode. From the selected area of the tumor, biopsy material was taken (presumably homogeneous in its properties) with subsequent measurement of spectra and combined images using the developed device. A high correlation was shown between the level of the fluorescence signal recorded spectroscopically and the brightness of the fluorescence image in the endoscopic channel of the device. The level of the fluorescent signal showed a high correlation with the degree of malignancy of tissues according to the results of pathomorphological examination.

2020, Bikmukhametova, L. R., Romanishkin, I. D., Savelieva, T. A., Orlov, A. V., Loschenov, V. B., Савельева, Татьяна Александровна, Лощенов, Виктор Борисович

Reducing the frequency of relapses after surgical removal of glial tumors is a non-trivial task due to their infiltrative growth. The main way to solve this problem is fluorescent intraoperative navigation. However, in the absence of accumulation of a fluorescent marker in the tumor tissues, other diagnostic parameters are required to find the boundaries of such tumors. Raman spectroscopy has the advantages of optical spectroscopy such as speed and non-invasiveness. With an exhaustive database of reference spectra of those components that can be expressed in glial tumors, Raman scattering spectroscopy allows multivariate diagnosis of such tumors and their intraoperative demarcation.