Vol 6, No 4 (2025)

BACKGROUND: Radioligand therapy with actinium-225–prostate-specific membrane antigen (²²⁵Ac-PSMA) is a novel and promising treatment modality for metastatic castration-resistant prostate cancer. Whole-body magnetic resonance imaging (WB-MRI) is a noninvasive, non-ionizing imaging technique that provides comprehensive information on skeletal and extraskeletal metastatic lesions, structured using the MET-RADS-P (METastasis Reporting and Data System for Prostate Cancer) and enabling detailed assessment of treatment response. However, the use of this system has not been widely adopted, and its diagnostic accuracy requires clinical validation.

AIM: This study aimed to evaluate the interim efficacy of ²²⁵Ac-PSMA radioligand therapy using WB-MRI based on MET-RADS-P criteria in patients with metastatic castration-resistant prostate cancer, assess method reproducibility (intra-observer agreement), and compare imaging findings with changes in prostate-specific antigen (PSA) levels.

METHODS: WB-MRI was performed twice in patients with metastatic castration-resistant prostate cancer: before administration of ²²⁵Ac-PSMA-617 with activity 6–12 MBq and 1–2 months after a single cycle of radioligand therapy, with parallel measurement of PSA levels. Prospective response assessment was conducted using MET-RADS-P criteria for WB-MRI and PCWG criteria for PSA level trends. Reproducibility of MET-RADS-P criteria was evaluated through repeated reading of WB-MRI studies by the same radiologist with a 6-month interval.

RESULTS: After one cycle of radioligand therapy, MET-RADS-P progression was identified in 4 of 20 patients with metastatic castration-resistant prostate cancer (20%) who completed the study. In three of these patients, progression was detected at an earlier time point than indicated by PSA level trends. More than half of the patients demonstrated discordant responses, including three with progression. Differences in PSA level trends were observed between concordant positive responses and various patterns of discordant response according to MET-RADS-P criteria. In cases of concordant response, the MET-RADS-P integrated assessment showed good correlation with biochemical response. MET-RADS-P criteria demonstrated excellent reproducibility for the primary response category pattern and for integrated response assessment. Reproducibility for the secondary response category pattern was substantial.

CONCLUSION: The use of MET-RADS-P criteria to WB-MRI in patients with metastatic castration-resistant prostate cancer enabled earlier detection of progression in skeletal and extraskeletal lesions compared with PSA level trends and demonstrated good intra-observer agreement. Further investigation of the prognostic value of MET-RADS-P criteria in the context of ²²⁵Ac-PSMA radioligand therapy is warranted.

This article is an adapted version of the “Use of the Fleischner Society Criteria for the Assessment of Pulmonary Nodules on Computed Tomography: Practice Guidelines” published in the series Best Practices in Radiological and Instrumental Diagnostics (2024, Issue 142). These guidelines reflect the consensus of the Fleischner Society regarding pulmonary nodules detected by computed tomography. They are developed to reduce the number of unnecessary follow-up examinations and provide clear management strategies for incidentally detected pulmonary nodules in patients outside lung cancer screening programs. Outside lung cancer screening, the unified Fleischner Society terminology and the standardized interpretation of chest computed tomography findings facilitates effective communication and mutual understanding among healthcare professionals in clinical practice, medical education, and scientific research. These practice guidelines were approved by the Chief External Expert in Radiological and Instrumental Diagnostics of the Moscow City Health Department and were recommended by the Scientific Expert Council of the Moscow City Health Department.

The guidelines are intended for radiologists, heads of radiology units or departments of diagnostic imaging, and chief medical officers of healthcare institutions that include radiology units or departments of diagnostic imaging.

The article presents an assessment of body composition markers measured by imaging in clinical practice for postmenopausal and aging women. Body composition changes with aging and is specifically affected by endocrinological changes occurring with menopause. Several imaging markers have been proposed and used in the assessment of body composition status. The associations of different imaging markers with cardiometabolic risk and risks for other diseases, with impact on morbidity/mortality, functional impairment, and frailty, are discussed. The imaging markers confirmed by evidence and are applicable to clinical practice are highlighted. With this purpose, the current level of evidence in the literature on reliability and potential associations of each relevant marker was reviewed.

This review describes what can and should be done with available imaging tools (e.g., dual-energy x-ray absorptiometry, ultrasound, computed tomography, and magnetic resonance imaging) in dedicated and opportunistic settings (i.e., tests for assessing body composition vs those for other clinical reasons but wherein exploitation of imaging data is possible) to improve the management and understanding of lifestyle needs of postmenopausal women and thus to prevent or decrease unhealthy aging and rate of women with aging-related diseases.

The clinical signs of multifocal brain lesions, including multiple sclerosis, are highly variable and largely depend on lesion site and size. Differential diagnosis of such changes may be challenging in certain cases. Vascular, inflammatory, infectious, and hereditary diseases may demonstrate similar magnetic resonance imaging patterns, whereas their assessment is limited by technical factors and human visual perception. In recent years, novel approaches such as texture analysis and radiomics have been increasingly integrated into radiological research, facilitating the acquisition of imaging details that would otherwise remain undetectable by the naked eye. These methods include first-order statistical analysis of signal intensities, gray-level co-occurrence and gray-level run-length matrices, fractal and wavelet analyses, and the development of predictive models using machine learning algorithms. Radiomics was initially developed for oncologic imaging; however, now its capabilities are also applied in the diagnosis of other conditions.

This article presents a review of the current scientific data on the use of texture analysis and radiomics in the differential diagnosis of demyelinating diseases, with a particular focus on multiple sclerosis. Data search was conducted in PubMed and eLibrary using the keywords “radiomics,” “digital image texture analysis,” “multiple sclerosis,” “радиомика” (radiomics), “текстурный анализ” (texture analysis), and “рассеянный склероз” (multiple sclerosis). The search period covered the last 9 years. Only original studies (n = 17) investigating the use of radiomics and digital image texture analysis in the diagnosis of demyelinating diseases were included in this review.

Texture analysis and radiomics represent promising adjunctive tools for the evaluation of multifocal brain lesions in demyelinating diseases. However, their implementation in clinical practice requires the development of optimized feature extraction algorithms, identification of the most informative texture parameters, and standardization and validation of the resulting imaging biomarkers.

Nonbacterial thrombotic endocarditis is a rare condition that is typically asymptomatic and is most often diagnosed post mortem in patients with cancer, systemic lupus erythematosus, or antiphospholipid syndrome. In this condition, vegetations are predominantly localized in the left heart. In contrast, isolated involvement of the tricuspid valve in nonbacterial thrombotic endocarditis is extremely rare, and the the incidence of this localization has not been established.

This article presents a clinical case of nonbacterial thrombotic endocarditis in a patient with pancreatic cancer and liver metastases, characterized by a rare variant of isolated tricuspid valve involvement and manifested by recurrent episodes of pulmonary embolism despite ongoing anticoagulant therapy.

The complexity of this case was due to recurrent pulmonary embolism following any attempt of even short-term discontinuation of anticoagulant therapy. At the same time, withdrawal of anticoagulation was a mandatory prerequisite for the safe biopsy of a metastatic lesion and subsequent histological verification, without which adequate antitumor therapy could not be initiated.

Given the limited amount of available data on the management of such patients, the therapeutic approach requires individualization and nonstandard clinical decision-making by the treating physician.

Lymphomas constitute a heterogeneous group of cancers characterized by uncontrolled clonal proliferation of lymphoid cells. They may arise in lymph nodes and extranodal organs and tissues. Primary mediastinal large B-cell lymphoma is a rare and aggressive subtype of B-cell lymphomas, accounting for approximately 2%–3% of all non-Hodgkin lymphomas.

This article presents a clinical case of primary mediastinal lymphoma with cardiac involvement in a 66-year-old female patient. The initial signs of the disease mimicked acute coronary syndrome, including chest pain, dyspnea, and cardiac rhythm disturbances. Diagnostic evaluation revealed a rapidly progressive mediastinal tumor invading the pericardium and myocardium, confirmed using modern imaging modalities (echocardiography, cardiac magnetic resonance imaging, and computed tomography) and pathological examination. Despite intensive treatment, the patient’s condition deteriorated rapidly, resulting in a fatal outcome.

This case highlights the diagnostic challenges associated with cardiac and pericardial involvement in mediastinal lymphomas and demonstrates the necessity of a multidisciplinary approach in the management of such rare and aggressive diseases.