The aim of study is to evaluate the tolerability and effectiveness of photodynamic therapy as an organ‑preserving treatment in patients with vulvar leukoplakia. 50 patients with a verifed diagnosis of «vulvar leukoplakia» were included in the study. The age varied from 27 to 74 years. The method of treatment assumed the use of the photosensitizer рhotolon (RUE «Belmedpreparaty», Belarus) administered intravenously in doses of 1.8–2.5 mg/kg. Photoirradiation of pathological foci was carried out 2.5–3 hours after intravenous injection of photolon® using a semiconductor laser «UPL PDT» (LEMT, Belarus, λ=661 nm) at exposure doses from 30 to 100 J/cm2 with a power density of 100–170 mW/cm2. The treatment was performed under medical anesthesia. The results of treatment were evaluated using clinical data. Adverse reactions and complications after the introduction of the photosensitizer and photoirradiation have not been observed. Complete clinical regression of the treated pathological foci was noted in 100% of cases with a follow‑up observation 1 month after the treatment. At follow‑up after 3 months, local recurrences of the disease were detected in 4 cases, which were successfully treated with repeated photo‑dynamic therapy sessions. The percentage of complete regressions was 92%, partial – 8%. The obtained results allow judging on the possibility of using photodynamic therapy in the treatment of patients with vulvar leukoplakia, which allows to preserve the organ and obtain a satisfactory functional and cosmetic result.

Cytological studies on lymph nodes of abdominal lymphodissection zone after local intraoperative photodynamic therapy (IOPDT) of gastrointestinal cancers were carried out. As a result of the PDT, the metastatic cells are destroyed, their cytoplasmic membranes and the cytoplasm disappears, leaving behind interphase nuclei ("naked nuclei") (p<0,0001). Cytological confrmation of apoptosis (the presence of apoptotic bodies) in metastatic lymph nodes after IOPDT sessions on the lymph nodes of the abdominal lymphodissection zone is also presented.

The present work is devoted to the study of pharmacokinetics of infrared photosensitizer (PS) based on hydroxyaluminium tetra‑3‑phenylthiophthalocyanine in a sterically stabilized liposomal form. The study was carried out on adult female mice. The PS was administered once intravenously at a dose of 6 mg / kg. Evaluation of the PS accumulation dynamics in the mice tissues and organs was performed at time intervals from 5 minutes to 7 days using spectral‑fluorescent method. The maximum accumulation of the PS photoactive form was recorded in lungs (32 µg / g in the interval of 5–30 minutes after introduction), liver (20.8 µg / g in the interval of 4–24 hours after introduction) and spleen (28 µg / g 4 hours after introduction). At the same time, by the end of the observation period (7 days after administration), trace amounts of the PS photoactive form were still detected in the liver and the spleen at a calculated concentration of 0.5‑1 µg / g. The PS accumulated the least in muscles and skin. The fluorescent signal from the PS accumulated in skin was detectable almost immediately, and its concentration remained at the same level (1.2‑1.5 µg / g) for up to 3 days of observation. In the muscles, the concentration of the PS reached 1.5 µg / g 15 minutes after administration, and then gradually decreased until 0.25 µg / g at 24 hours. Data on the pharmacokinetics of PS in blood, basic organs and tissues of animals were obtained, pharmacokinetic parameters were calculated. 7 days after the administration, the PS concentration in the skin and muscles was below the detection limit. The studies confrmed that PEGylation of the PS liposomal form slows down the process of its capture by reticulo‑endothelial system. It was shown that the PS circulates in blood and organs of mice for a long time and it completely distributes only when 4 hours pass after administration.

The paper presents the results of a comparative study of methods of cluster analysis of optical intraoperative spectroscopy data during surgery of glial tumors with varying degree of malignancy. The analysis was carried out both for individual patients and for the entire dataset. The data were obtained using combined optical spectroscopy technique, which allowed simultaneous registration of diffuse reflectance spectra of broadband radiation in the 500–600 nm spectral range (for the analysis of tissue blood supply and the degree of hemoglobin oxygenation), fluorescence spectra of 5‑ALA induced protoporphyrin IX (Pp IX) (for analysis of the malignancy degree) and signal of diffusely reflected laser light used to excite Pp IX fluorescence (to take into account the scattering properties of tissues). To determine the threshold values of these parameters for the tumor, the infltration zone and the normal white matter, we searched for the natural clusters in the available intraoperative optical spectroscopy data and compared them with the results of the pathomorphology. It was shown that, among the considered clustering methods, EM‑algorithm and k‑means methods are optimal for the considered data set and can be used to build a decision support system (DSS) for spectroscopic intraoperative navigation in neurosurgery. Results of clustering relevant to thepathological studies were also obtained using the methods of spectral and agglomerative clustering. These methods can be used to postprocess combined spectroscopy data.

We present a clinical case with a complete endoscopic and clinical effect after endoscopic treatment of a patient with laryngeal cancer involving the upper third of the esophagus. The patient was treated as follows: conformal radiation therapy TFD = 40 gr, targeted chemotherapy using Cetuximab (total dose of 1800 mg). 1.5 months after the end of the treatment, a residual laryngopharyngeal tumor with a spread into the upper third of the esophagus was found during videolaryngoscopy examination. The result of the following histological examination was G2 squamous cell carcinoma. From August 2015 to February 2017, the patient underwent 8 photodynamic therapy sessions in combination with argon plasma coagulation. A control videolaryngoscopy, carried out 1 month after the fnal session, showed complete tumor regression without cicatricial deformity and narrowing of the esophageal lumen.