Relevance: Multiple brain metastases (BM) remain one of the central clinical challenges in neuro-oncology. Advances in systemic therapy and the widespread use of MRI have increased the detection of intracranial progression and required a re-evaluation of local treatment strategies, in which tumor control must be balanced against preservation of cognitive function and quality of life.

Purpose: To synthesize current evidence on stereotactic radiosurgery (SRS) in adults with multiple BM, to clarify the evidence supporting SRS without whole-brain radiotherapy (WBRT), and to evaluate dosimetric aspects, cognitive outcomes and patient selection criteria.

Materials and methods: A literature search was performed in PubMed/MEDLINE, Ovid and the Cochrane Library covering the period from January 2010 to April 2026. Eligible publications included original clinical studies, systematic reviews, meta-analyses, clinical guidelines and topical reviews addressing SRS/SRT in adults with multiple (predominantly ≥5) BM. This is a narrative review with a structured search; no protocol was registered, and PRISMA flow, formal risk-of-bias assessment and meta-analysis were not performed.

Results: Accumulated evidence indicates that the absolute number of intracranial lesions is not a sufficient criterion for SRS eligibility. In patients with 5–10 BM meeting JLGK0901 inclusion criteria, overall survival and complication rates are comparable to those with 2–4 lesions. For >10 BM the evidence base is weaker and mostly retrospective, yet SRS remains clinically justified in carefully selected patients with limited total tumor volume, preserved performance status and controlled systemic disease. The principal constraint in multiple BM is not the lesion count but the total tumor volume and dosimetric feasibility, with V₁₂ (single-fraction SRS) and V₂₀/V₂₄(3- and 5-fraction SRT) as key planning parameters.

Conclusion: SRS for multiple BM should be regarded as a selective local strategy, the appropriateness of which is determined by the combination of treatment feasibility (total tumor volume, dosimetric constraints) and clinical rationale (GPA-based survival prognosis, control of extracranial disease, availability of systemic therapy). A local-only strategy is justified only when pre-planned MRI surveillance and timely salvage options are available.

Relevance: Convolutional neural networks (CNN) are broadly used for medical images segmentation. In radiation oncology, image segmentation is the most crucial and time-consuming part of the treatment. CNNs can facilitate this process by reducing the time spent on image segmentation and inter-observer variability of the contours.

Purpose: To demonstrate the training and application of an open-source CNN nnU-Net for segmenting organs at risk in CT images of patients with head and neck cancer for radiotherapy planning.

Materials and methods: Contoured CT images of 100 head and neck cancer patients, who were treated in Moscow International Cancer Center in 2024-2025, were used for the CNN training. Validation of the resulting segmentation was performed on 10 head and neck cancer patients’ CT images using Dice coefficient, 95-percentile Hausdorff distance, average surface distance.

Results: The trained CNN is able to automatically segment 22 head and neck organs at risk. Quality assessment of the resulting segmentation was conducted with an average Dice coefficient of 0,84.

Conclusion: Open-source solutions, as the nnU-Net CNN, have a potential to be integrated in radiation oncology workflow as an automated segmentation tool with minimal financial cost.

Purpose: To optimize the evaluation of response dynamics during PSMA-targeted radioligand therapy (RLT) ¹⁷⁷Lu-PSMA based on a comprehensive analysis of prostate-specific antigen (PSA), post-therapeutic single-photon emission computed tomography/ computed tomography (SPECT/CT), and positron emission tomography/computed tomography (PET/CT) with ¹⁸F-PSMA-1007 in patients with metastatic castration-resistant prostate cancer (mCRPC).

Material and methods: A retrospective single-center study was conducted, including 78 patients with mCRPC who received 2 to 6 cycles of ¹⁷⁷Lu-PSMA-617 therapy. Monitoring included three levels: PSA dynamics (before each cycle), post-therapeutic SPECT/ CT (24 hours after each administration), and PET/CT with ¹⁸F-PSMA-1007 (baseline and after 2, 4, and 6 cycles). The dynamics of radiopharmaceutical uptake, SUVmax values, and concordance between methods were assessed. The primary endpoint was progression-free survival (PFS) assessed by PET/CT.

Results: The median PFS by PET/CT in the overall cohort was 9 months. Stratified by PET/CT dynamics after 2 cycles, median PFS was: positive dynamics — 14 months, divergent — 8 months, negative — 5 months (p30 % reduction in SUVmax in bone lesions on SPECT/CT after the 1st cycle was associated with longer PFS (13.5 months vs. 5.5 months; p < 0.001). Concordance between PSA and PET/ CT was moderate (κ=0.44), with discordance observed in 17.9 % of cases. The highest concordance was between SPECT/CT and PET/ CT (κ=0.68-0.70). PSMA-negative progression was detected in 5 patients (6.4 %), with 4 of them showing decreasing or stable PSA levels. A >30 % reduction in SUVmax in bone lesions on SPECT/CT after the 1st cycle was associated with longer PFS (13.5 months vs. 5.5 months; p < 0.001). No grade ≥3 adverse events were recorded.

Conclusion: Combined monitoring (PSA + SPECT/CT after each cycle + PET/CT with ¹⁸F-PSMA-1007 every 2 cycles) is optimal for response assessment during ¹⁷⁷Lu-PSMA therapy. Isolated PSA assessment is insufficient due to high discordance with imaging methods. Post-therapeutic SPECT/CT allows outcome prediction, while PET/CT is essential for detecting PSMA-negative progression and making decisions on therapy continuation or cessation. The proposed three-level approach enables timely treatment individualization.

The development of drugs for boron neutron capture therapy, the design of «proof of concept» studies, and the collection of efficacy data from both preclinical (animal) and clinical (human) trials — as well as the process of getting these drugs officially approved — are still unsolved problems worldwide. This is mainly because of the unique biological effect that occurs when the 10B isotope inside the drug interacts with epithermal neutrons from different sources. In this paper, we discuss the pharmaceutical and technological requirements that must be met to obtain a marketing license for such products, and we also highlight the main restrictions that arise during registration.

The article presents a literature review dealing with rare mesenchymal tumors of the prostate, illustrated by a series of corresponding clinical cases. Information on the prevalence of these neoplasms, their clinical manifestations, and CT and MRI features are briefly summarized.

Five rare cases of mesenchymal tumors of the prostate in patients of various ages (from 6 months to 74 years) who underwent different examinations including pelvic CT/MRI with intravenous contrast enhancement and treatment at the N.N. Blokhin National Medical Research Center of Oncology are described. The imaging appearance of the identified tumors in all 5 patients as large, heterogeneous, solid masses with fairly distinct, smooth or wavy contours had no characteristic features (before and after intravenous contrast enhancement), which did not allow us to specify the nature of the tumor process.

Conclusion: accurate recognition of rare mesenchymal neoplasms of the prostate using various radiological methods is extremely difficult and practically impossible; therefore, the final diagnosis of such lesions should be based on histological and immunohistochemical data.

Purpose: To improve the efficiency of diagnostic monitoring of patients with meningiomas after stereotactic radiosurgery.

Materials and methods: This retrospective, single-center study included 50 patients with meningiomas who underwent stereotactic radiosurgery (SRS) using the Gamma Knife ICON (Elekta). The mean age was 64.9 ± 11.6 years. Skull base meningiomas were detected in 21 of 50 patients (42.0 %), parasagittal meningiomas in 18 of 50 (36.0 %), and convexital meningiomas in 11 of 50 (22.0 %). Histological verification (based on the results of the previous resection) was performed in 24 patients: Grade I — 10, Grade II — 8, Grade III — 6. Follow-up MRI examinations were performed 3, 6, and 12–14 months after SRS. For each tumor, changes in area (using the RANO criteria) and volume were determined; agreement between the methods was assessed using the Cohen’s kappa coefficient. In addition, qualitative MRI features were assessed: contrast enhancement pattern, perifocal edema, margin clarity, and the presence of new lesions.

Results: According to the volume classification, progression was observed in 12 of 50 patients (24.0 %; 95 % CI: 14.3–37.4), stabilization in 32 of 50 (64.0 %), and response in 6 of 50 (12.0 %). According to the RANO criteria: 10 of 50 (20.0 %) / 21 of 50 (42.0 %) / 19 of 50 (38.0 %), respectively. The agreement between the two methods was 68.0 % (Cohen’s kappa 0.498). The grade of malignancy was significantly associated with progression (chi-square p = 0.043; pairwise Grade I vs III: p = 0.035); localization was not (p = 0.84). A combination of qualitative MR features demonstrated high diagnostic efficacy: persistent heterogeneous contrast enhancement at 12-14 months, combined with pathological dynamics of perifocal changes. Each feature was characterized by a different sensitivityspecificity ratio: the appearance of new lesions — Sn 41.7 %, Sp 100 %; perifocal edema — Sn 41.7 %, Sp 92.1 %; the appearance of fuzzy margins — Sn 25.0 %, Sp 100 %.

Conclusion: Quantitative volumetric assessment of meningiomas after SRS proved more sensitive compared to area-based assessment (RANO), additionally identifying cases of occult progression in 2 patients (4 %). The grade of meningioma malignancy is a significant factor associated with the risk of progression; a significant difference was found between Grade I and Grade III. The location of the lesion did not affect treatment outcomes. A set of qualitative MRI features (characteristics and dynamics of contrast enhancement, perifocal edema, clarity of contours, new lesions) provides the basis for differential diagnosis of true progression and post-radiation reactions.

Relevance: Cutaneous melanoma is characterized by high metastatic potential, and regional lymph node involvement is a key prognostic factor.

Purpose: To develop and evaluate a non-invasive logistic regression model for predicting regional lymph node metastases.

Materials and methods: A retrospective single-center study included 121 patients. Clinical, ultrasound, elastography and scintigraphy parameters were used as predictors; morphological data were excluded.

Results: The model demonstrated a high discriminative ability (ROC AUC ≈ 0.94). At a threshold of p = 0.316, the sensitivity was ≈0.85, the specificity was ≈0.96, the accuracy was ≈0.93, at a lower threshold of p = 0.103, the sensitivity reached about 0.93 with a specificity of about 0.79.

Conclusion: The model may be used for primary risk stratification and guiding invasive staging decisions.

Relevance: Verification of recurrent laryngeal and hypopharyngeal cancer after organ-preserving treatment is often challenging due to the submucosal location of the tumor focus, inaccessible to standard endoscopic techniques.

Purpose: To evaluate the feasibility of percutaneous harpoon biopsy under ultrasound guidance for verification of recurrent laryngeal and hypopharyngeal cancer.

Materials and methods: A total of 56 patients with clinical and radiological signs of recurrence, not amenable to conventional biopsy methods, were enrolled. Ultrasound examination of the larynx and hypopharynx was performed in all cases. Subsequently, 29 patients underwent percutaneous harpoon biopsy under ultrasound guidance, and 27 patients underwent biopsy under endotracheal anesthesia during direct microlaryngoscopy.

Results: Ultrasound features of recurrent hypopharyngeal tumors (indistinct margins in 64.9 %, irregular borders in 73.0 %, heterogeneous structure in 75.7 %) were significantly more common than in laryngeal tumors (p < 0.05). In the main group, biopsy material was obtained in 24 (82.8 %) patients, with recurrence confirmed in 13 (44.8 %). No complications requiring additional intervention were recorded. The time from hospitalization to diagnostic procedure was shorter in the main group compared to the control group.

Conclusion: Percutaneous harpoon biopsy under ultrasound guidance provides sufficient material for histological and immunohistochemical examination, reduces diagnostic time, and may serve as the method of choice in patients with submucosal recurrences after unsuccessful endoscopic verification attempts.

Purpose: To summarize existing data on the application of high-intensity focused ultrasound (HIFU) and low-intensity focused ultrasound (LIFU) in the treatment of intracerebral brain tumors. Special attention is paid to the practical application of LIFU in the field of drug therapy for glioblastomas.

Materials and methods: The article presents a systematic review of international publications and clinical studies concerning the application of HIFU and LIFU, including data from experimental models, preclinical and clinical studies, covering biophysical mechanisms of ultrasound effects on tissues, parameters of its application, as well as results of therapy for various oncological and neurological diseases.

Results: It is demonstrated that the LIFU method enables reversible neuromodulation, improves motor functions, and reduces the activity of inflammatory processes following iatrogenic exposure; it is capable of safely and reversibly altering the permeability of the blood-brain barrier (BBB) to facilitate the delivery of therapeutic agents into the brain. Combined application of LIFU and drug therapy allows enhancing the anti-tumor effect in patients with glial tumors.

Conclusion: HIFU and LIFU methods are promising, complementary technologies with distinct mechanisms of action and clinical applications. HIFU provides effective and controlled tissue destruction via high-intensity thermal effects, while LIFU performs the function of neuromodulation and temporary reversible increase of BBB permeability. Modern developments and integration of these methods contribute to expanding therapeutic possibilities in the treatment of brain diseases and require further study to optimize protocols and enhance the clinical efficacy of the methods.

Purpose: To review the literature and synthesize information regarding the mechanisms by which high temperatures affect tumor tissue during hyperthermia.

Materials and methods: Forty-one sources were analyzed. Data were gathered on the effects of hyperthermia on blood flow, intratumoral partial oxygen pressure (pO₂), and pH levels, as well as on the oxygen effect during tumor heating. Information was also collected regarding the mechanisms of interaction between hyperthermia and radiotherapy—specifically their synergism, the sequence and timing intervals between the two modalities, and the phenomena of tumor cell thermotolerance and its underlying molecular mechanisms.

Results: Based on the data from the cited articles, the following conclusions and practical implications can be drawn: the target intratumoral temperature should range from 40 to 43 °C; uniform temperature distribution throughout the tumor volume is preferable; the duration of thermal exposure should be 40–60 minutes; the interval between hyperthermia and radiotherapy should be minimal and not exceed 60 minutes; the sequence of hyperthermia and radiotherapy administration is not critical; and the interval between hyperthermia sessions should be at least 3–4 days.

Introduction: Hybrid positron emission tomography and computed tomography (PET/CT) is widely used in experimental oncology; however, on native CT images, tumor tissue is indistinguishable from normal soft tissues. Contrast agents based on gold nanoparticles (AuNPs) have been proposed to address this issue.

Purpose: To experimentally validate the use of AuNPs as a CT contrast agent for PET/CT imaging of subcutaneous and intracranial B16F10 tumor models.

Materials and methods: AuNPs with a 6 ± 2 nm gold core were synthesized by laser ablation and coated with polyethylene glycol. C57Bl/6 mice with subcutaneous B16F10 melanoma (n = 5) received AuNPs intravenously at a dose of 940 ± 30 mg Au/kg; PET/CT with 18F-FDG was performed at 1, 3, and 5 days post-injection. The control group (n = 5) received no AuNPs and underwent PET/CT at the same time points. Three mice with intracranial melanoma B16F10 underwent PET/CT 24 hours after AuNP injection (680 ± 40 mg Au/kg). Radiodensity (HU), SUV_max, SUV_mean, and tumor volume were assessed.

Results: In the subcutaneous tumor, AuNPs accumulated predominantly at the periphery of the lesion: radiodensity increased from 97 ± 12 HU to 274 ± 61 HU at day 1 and to 345 ± 120 HU at day 5. This enabled clear delineation of tumor borders and measurement of anatomical volume. In the intracranial model, AuNPs were uniformly distributed throughout the tumor, increasing radiodensity from 137 ± 9 HU to 236 ± 28 HU. In the subcutaneous tumor, a trend toward increased SUV_max and SUV_mean was observed in the experimental group at days 1–3 post-injection (p = 0.06–0.08), presumably associated with the activation of tumor-associated macrophages phagocytosing the nanoparticles.

Conclusion: ¹⁸F-FDG PET/CT with AuNP contrast enhancement allows simultaneous assessment of tumor metabolic activity and precise anatomical borders and can be recommended for in vivo studies in experimental oncology.

An 84-year-old woman presented with two adjacent masses in the left kidney, in whom the MRI features of the upper-pole lesion were consistent with clear cell renal cell carcinoma, while the intrapelvic component mimicked a urothelial neoplasm. Based on the imaging findings and the clinical presentation, intraoperative ureteroscopy was planned to determine the extent of surgery. Ureteroscopy was performed first and revealed a yellowish, encapsulated mass in the upper calyceal group, without papillary projections, consistent with renal cell carcinoma. Nephrectomy was subsequently performed. Histopathological examination demonstrated a single tumor process: clear cell renal cell carcinoma with ulceration and infiltration of the urothelium of the pelvicalyceal system. This case demonstrates the limitations of MRI in differentiating heterogeneous multinodular clear cell renal cell carcinoma from a urothelial tumor and underscores the need for a multidisciplinary approach and mandatory histological verification.