Bilateral rapidly destructive coxopathy in rheumatoid arthritis.

Rapidly destructive coxopathy (RDC) is a rare type of coxarthritis marked by swift deterioration of the hip joint. Although its cause remains unclear, several pathophysiological mechanisms are proposed. To comprehensively analyze this poorly understood condition, a literature search was conducted focusing on associations of bilateral RDC and rheumatoid arthritis (RA). The problem of long-standing RA, bilateral RDC with a febrile episode that preceded a rapid decline in mobility and severe hip pain, with radiological assessment confirmed bilateral hip destruction, was presented. Rapidly destructive coxopathy, especially when linked to RA, poses diagnostic and therapeutic challenges. Our review confirmed by the clinical picture emphasizes the need for vigilance in RA patients with hip involvement and calls for further research to understand RDC's mechanisms and enhance clinical care.

Accuracy of deformable image registration-based intra-fraction motion management in Magnetic Resonance-guided radiotherapy.

Background and Purpose: Intra-fraction motion management is key in Stereotactic Ablative Radiotherapy (SABR) gated delivery. This study assessed the accuracy of automatic tumor segmentation in the delivery of MR-guided radiotherapy (MRgRT) by comparing it to manual delineations performed by experienced observers. Materials and Methods: Twenty patients previously treated with MR-guided SABR for thoracic and abdominal tumors were included. Five observers with at least two years of experience in MRgRT manually delineated the gross tumor volume (GTV) for 20 patients on 240 frames of a cine MRI on a sagittal plane. Deformable Image Registration (DIR) based GTV contours were propagated using four different algorithms from a reference frame to subsequent frames.Geometrical analysis based on the Dice Similarity Coefficient (DSC), centroid distance and Hausdorff Distance (HDD) were performed to assess the inter-observer variability and the accuracy of automatic segmentation. A Confidence Value (CV) metric for the reliability of the tumor auto-contouring was also calculated. Results: Inter-observer delineation variability resulted in mean DSC of 0.89, HDD of 5.8 mm and centroid distance of 1.7 mm. Tumor auto-contouring by the four DIR algorithms resulted in an excellent agreement with the manual delineations by the experienced observers. Mean DSC for each algorithm across all patients was greater than 0.90, whereas the HDD and centroid distances were below 4.0 mm and 1.5 mm, respectively. The CV showed a strong correlation with the DSC. Conclusions: DIR-based auto-contouring in MRgRT exhibited a high level of agreement with the manual contouring performed by experts, allowing accurate gated delivery.

Vascular effects of biologic and targeted synthetic antirheumatic drugs approved for rheumatoid arthritis: a systematic review.

BACKGROUND: Rheumatoid arthritis (RA) increases the risk of cardiovascular disease (CVD), with inflammation playing a key role. Biologic and targeted synthetic drugs used to treat RA can induce systemic immunomodulation and may have pleiotropic effects on vascular function, making it crucial to investigate their impact on CVD risk in RA patients. METHODS: A systematic review of the literature was conducted to investigate the impact of biologic and targeted synthetic treatments approved for RA on various cardiovascular markers, including endothelial function, arterial stiffness, and subclinical atherosclerosis. Our analysis included a search of the MedLine (via PubMed) and Web of Science databases using a pre-determined search strategy. We conducted a narrative synthesis of the included studies due to heterogeneity in study design and outcome measures. RESULTS: From an initial pool of 647 records, we excluded 327 studies based on their titles and abstracts, and we selected 182 studies for final examination. Ultimately, 58 articles met our inclusion criteria and were included in our systematic review. Our analysis of these studies revealed a positive effect of biologic and targeted synthetic therapies on vascular dysfunction associated with RA. However, the impact of these treatments on subclinical atherosclerosis was inconsistent. CONCLUSION: Overall, our systematic review provides important insights into the potential cardiovascular benefits of biologic and targeted synthetic treatments for RA by a still unknown mechanism. These findings can inform clinical practice and contribute to our understanding of their possible effects on early vascular pathology. Key Points • Great heterogeneity of methods are used to evaluate the endothelial function and arterial stiffness in patients with RA on biologic and targeted synthetic antirheumatic drugs. • Most studies have shown a considerable improvement in endothelial function and arterial stiffness with TNFi, despite some studies reporting only transient or no improvement. • Anakinra and tocilizumab may have a beneficial effect on vascular function and endothelial injury, as indicated by increased FMD, coronary flow reserve, and reduced levels of biomarkers of endothelial function, while the overall impact of JAKi and rituximab remains inconclusive based on the reviewed studies. • To fully comprehend the distinctions between biologic therapies, more long-term, well-designed clinical trials are necessary using a homogeneous methodology.

Influence of photon energy cuts on PET Monte Carlo simulation results.

PURPOSE: The purpose of this work is to study the influence of photon energy cuts on the results of positron emission tomography (PET) Monte Carlo (MC) simulations. METHODS: MC simulations of PET scans of a box phantom and the NEMA image quality phantom are performed for 32 photon energy cut values in the interval 0.3-350 keV using a well-validated numerical model of a PET scanner. The simulations are performed with two MC codes, egs_pet and GEANT4 Application for Tomographic Emission (GATE). The effect of photon energy cuts on the recorded number of singles, primary, scattered, random, and total coincidences as well as on the simulation time and noise-equivalent count rate is evaluated by comparing the results for higher cuts to those for 1 keV cut. To evaluate the effect of cuts on the quality of reconstructed images, MC generated sinograms of PET scans of the NEMA image quality phantom are reconstructed with iterative statistical reconstruction. The effects of photon cuts on the contrast recovery coefficients and on the comparison of images by means of commonly used similarity measures are studied. RESULTS: For the scanner investigated in this study, which uses bismuth germanate crystals, the transport of Bi X(K) rays must be simulated in order to obtain unbiased estimates for the number of singles, true, scattered, and random coincidences as well as for an unbiased estimate of the noise-equivalent count rate. Photon energy cuts higher than 170 keV lead to absorption of Compton scattered photons and strongly increase the number of recorded coincidences of all types and the noise-equivalent count rate. The effect of photon cuts on the reconstructed images and the similarity measures used for their comparison is statistically significant for very high cuts (e.g., 350 keV). The simulation time decreases slowly with the increase of the photon cut. CONCLUSIONS: The simulation of the transport of characteristic x rays plays an important role, if an accurate modeling of a PET scanner system is to be achieved. The simulation time decreases slowly with the increase of the cut which, combined with the accuracy loss at high cuts, means that the usage of high photon energy cuts is not recommended for the acceleration of MC simulations.