Introduction. Difficult diagnosis, aggressive progression, and absence of an increase in treatment effectiveness (especially in patients with osteosarcoma and Ewing sarcoma) make malignant tumors of the bones a significant medical problem. Use of traditional therapy methods is often associated with development of drug resistance and frequent recurrences. Therefore, there is a need for new treatment strategies and overcoming of the limitations of traditional methods through their improvement, combination or substitution to achieve higher survival, lower recurrence rate, and wider availability for patients with bone tumors.Aim. To present a clinical observation of the use of a new method of radical intraoperative thermal ablation for bone tumors, assess exposure tolerance, long-term oncological and functional results.Clinical observation. This article presents a clinical case of the use of a new radical treatment method for a patient with tibial osteosarcoma who underwent intraoperative thermal ablation using a new domestic complex of local hyperthermia “Phoenix-2”.Results. A session of intraoperative thermal ablation was performed in the operating room under anesthesia directly in the wound for 48 minutes. Access to the tumor-affected bone was performed with the standard oncological approach (en-block), the bone was not transected or removed. A constant heating mode of 90 °С was used, assuming a gradual increase in temperature. Thus, 60 °С reached 20 minutes, and the temperature at the end of high-temperature exposure was 78 °С (inside the medullary canal). The operation time was 2 hours 30 minutes. The postoperative period proceeded without complications. After 38 months of follow-up, examinations did not reveal any recurrence or progression in the patient.Conclusion. The technique of radical intraoperative thermal ablation using a local hyperthermia complex Phoenix-2 is effective and allows to widen the toolkit of treatment methods for patients with bone tumors. It can serve as an alternative or addition to organ-preserving surgical treatment without costly reconstruction stages.

Circulating small extracellular vesicles (sEVs) are emerging as potential biomarkers for glioblastoma progression. This study aimed to compare the levels of matrix metalloproteinases (MMP2 and MMP9), terminal complement complex (C5b-9), and VEGF-A in circulating sEVs in glioblastoma patients (GBMPs) with and without tumor recurrence. Using differential ultracentrifugation, sEVs were isolated from blood samples of GBMPs with no tumor recurrence for over one year (n = 6) and after first relapse (n = 14). The vesicles were characterized and quantified using flow cytometry. In both groups, C5b-9 was predominantly detected on tumor-specific circulating sEVs (glial fibrillary acidic protein (GFAP)-positive sEVs) with high VEGF-A expression, while C5b-9 was significantly less frequent on sEVs with low VEGF-A expression (p < 0.05). GFAP+VEGF+dimMMP2-C5b-9+ vesicles were rarely detected in GBMPs without relapse, suggesting their potential utility as biomarkers for a favorable relapse-free prognosis. In recurrent GBMPs, a positive correlation was observed between GFAP+VEGF+bright MMP2+C5b-9+ sEVs and MGMT gene promoter methylation levels (r = 0.543, p < 0.05). Additionally, a trend toward a negative correlation was found between GFAP+VEGF+bright MMP2+C5b-9- sEVs and mutant p53 expression in primary tumor tissue (r = −0.44, p = 0.114). These findings suggest that sEV profiles may serve as valuable prognostic markers for glioblastoma recurrence and treatment responses.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ КОЛИЧЕСТВЕННЫХ ДАННЫХ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ И МОРФОЛОГИЧЕСКОГО ИССЛЕДОВАНИЯ У ПАЦИЕНТОВ С ГИГАНТОКЛЕТОЧНОЙ ОПУХОЛЬЮ КОСТИ ПРИ ЛЕЧЕНИИ ДЕНОСУМАБОМ

Introduction. Bone tumors are heterogeneous group of skeletal neoplasms characterized by frequent recurrences, aggressive clinical course and low survival rates. The development of new treatment methods continues to pose pressing challenges. Radical intraoperative thermal ablation (RIT) using high-temperature exposure is emerging as a new and promising strategy for organ-preserving treatment. This study focuses on the effect of thermal ablation (TA) on tumors.Objective of the Study to assess the impact of TA (using the RIT method) on the viability of tumor cells.Material and Methods. The study included 8 patients with bone tumors. Tumors underwent TA at a temperature of 60 °C for 30 minutes ex vivo. Apoptosis was studied in tumor tissue samples before and after TA. Apoptosis was assessed using two methods: flow cytometry and the TUNEL assay.Results. The TA procedure developed by our scientific group represents a promising organ-preserving approach for treating malignant bone tumors. A temperature regime of 60 °C for 30 minutes was effective in initiating tumor cells death. This was confirmed by two independent methods – flow cytometry and TUNEL assay – which demonstrated a significant increase in the number of apoptotic cells immediately following the procedure and a notable rise in the number of cells exhibiting signs of late apoptosis one hour post thermal ablation. Therefore, the collected data confirm a pronounced antitumor effect immediately after implementing RIT.Conclusion. The findings confirm that RIT is a viable organ-preserving method for treating bone tumors, meriting further investigation to expand its application in clinical practice.

The purpose of the study was to develop and evaluate the technique for volumetric tumor segmentation based on diffusion-weighted magnetic resonance imaging (DW-MRI) in predicting and assessing the response to chemotherapy in patients with bladder cancer (BC). Material and Methods. We examined 26 patients with morphologically verified transitional cell carcinoma of the bladder. The group was characterized by the presence of one or several tumors with a size of 17 to 46 mm. Before planning chemotherapy according to the M-VAC scheme, a study and post-processing of DW-MRI with volumetric segmentation of lesions, assessment of the volume and apparent diffusion coefficient (ADC) in the entire tumor mass were performed. According to the ADC data, shape of the tumor and its relation to the bladder wall, the coefficient (C) for predicting the response to chemotherapy was calculated. Results. In the cases with a coefficient value below 0.51, a high risk of treatment failure was predicted, at C≥0.74, a positive effect of treatment was predicted. With a value of 0.51≤C<0.74, the prognosis was uncertain, stabilization was more likely. The sensitivity and specificity of the method were 92.3 % and 92.4 %, respectively. Conclusion. The method of volumetric segmentation makes it possible to predict and evaluate bladder cancer response to chemotherapy with a sufficiently high accuracy. The advantages of the method are the possibility of assessing the tumor regardless of the degree of filling of the bladder, with non-contrast MRI, and with large lesions.

Background: Giant cell tumor of bone (GCTB) is a relatively common benign bone tumor, accounting for 4–9.5 % of all primary bone neoplasms. Localization of GCTB is one of the most important differential diagnostic criteria, since the tumor affects certain parts of the skeleton. Until now, surgical treatment was considered the method of choice in the treatment of GCTB. However, in recent years, denosumab, a genetically engineered drug, has been widely used to treat this tumor. Denosumab treatment of GCTB prevents further tumor progression and reduces tumor size. Histological examination of the surgical specimen is undoubtedly the most objective method for assessing the effectiveness of the treatment. However, it is sometimes necessary to get information regarding the effectiveness of conservative therapy.Purpose: To analyze the density characteristics of denosumab-treated GCTB using CT densitometry.Material and methods: The study included 15 patients aged 28–59 years with histologically verified giantcell tumor, who received denosumab treatment followed by surgery. Tumor structure was assessed before starting denosumab therapy, after 3 and 6 courses of denosumab therapy.Results: Changes in the density parameters (the mean tumor density, standard deviation of density, increase in the median tumor density and standard deviation of density, index of the relative density of the tumor) measured by CT images were analyzed. These changes were statistically significant in GCTB patients before initiating therapy with denosumab, and after 3 and 6 courses of denosumab therapy.Conclusion: Thus, CT densitometry is a useful tool for assessing the density characteristics of the tumor in GCS patients treated denosumab.