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Simple Summary: The large-scale colorectal cancer screening program (CRCSP) in Flanders, Belgium, was suspended twice in 2020 due to the COVID-19 pandemic. The aim of this retrospective study was to estimate the influence of the COVID-19 pandemic on CRCSP uptake and to identify the disproportionate changes in uptake rate and screening interval in areas with different socioeconomic status (SES). We found that the COVID-19 pandemic had a short-lived influence on uptake rate and screening interval. Areas with lower SES led to a greater decrease in uptake rate and areas with higher SES showed a greater increase in screening interval during the COVID-19 pandemic. These findings suggest that tailored invitations on CRCSP during the pandemic are needed for low SES areas. Timely warnings help people living in high SES areas, who might delay participation, to adhere to screening intervals. Objectives: To assess the association of the COVID-19 pandemic with an uptake rate and screening interval between two screening rounds in colorectal cancer screening program (CRCSP) and identify the disproportionate correlation of socioeconomic status (SES) factors. Methods: An analysis was performed on aggregated screening and SES data at the area level in Flanders, Belgium, during 2018–2022. The screening uptake rate was the percentage of people returning self-test results within 40 days after invitation, and the screening interval was the number of days between current and previous screening. Differences in uptake rate and screening interval before and during COVID-19 were categorized into 10 quantiles, and determinants were evaluated using quantile regression models. Results: Significant change was seen from March to August 2020. The areas with the greatest decrease in uptake rate and screening interval had low population density, and areas with the greatest increase in screening interval had the highest income and percentage of home ownership. In regression analysis, more people living alone (β = −0.09), lower income (β = 0.10), and a higher percentage of home ownership (β = −0.06) were associated with a greater decrease in uptake rate. Areas with lower population density (β = −0.75), fewer people of Belgian nationality (β = −0.11), and higher income (β = 0.42) showed greater increases in screening interval. Conclusions: During the COVID-19 pandemic, people in areas with low SES were less likely to participate in screening, whereas people in areas with high SES were more likely to delay participation. A tailored invitation highlighting benefits of CRCSP is needed for people with low SES to improve uptake. Timely warnings could help people who delay participation adhere to screening intervals. [ABSTRACT FROM AUTHOR]

Aims Calciprotein particles (CPPs) are circulating calcium and phosphate nanoparticles associated with the development of vascular calcification (VC) in chronic kidney disease (CKD). Although recent studies have been focusing on associations of CPPs with the presence of VC in CKD, insights in the underlying processes and mechanisms by which CPPs might aggravate VC and vascular dysfunction in vivo are currently lacking. Here, we assessed the overall burden of abdominal VC in healthy kidney donors and CKD patients and subsequently performed transcriptome profiling in the vascular tissue obtained from these subjects, linking outcome to CPP counts and calcification propensity. Methods and results Calcification scores were quantified in renal arteries, iliac arteries, and abdominal aorta using computed tomography (CT) scans of kidney donors and CKD patients. The vascular tissue was collected from kidney donors (renal artery) and CKD patients (iliac artery), after which bulk RNA sequencing and gene set enrichment analysis (GSEA) were performed on a subset of patients. Calcification propensity (crystallization time, T50) was measured using nephelometry and CPP counts with microparticle flow cytometric analysis. Increased calcification scores (based on CT) were found in CKD patients compared to kidney donors. Transcriptome profiling revealed enrichment for processes related to endothelial activation, inflammation, extracellular matrix (ECM) remodelling, and ossification in CKD vascular biopsies compared to kidney donors. Calcification propensity was increased in CKD, as well as CPP counts, with the latter being significantly associated with markers of vascular remodelling. Conclusion Our findings reveal that CKD is characterized by systemic VC with increased calcification propensity and CPP counts. Transcriptome profiling showed altered vascular gene expression with enrichment for endothelial activation, inflammation, ECM remodelling, and ossification. Moreover, we demonstrate, for the first time, that vascular remodelling processes are associated with increased circulating CPP counts. Interventions targeting CPPs are promising avenues for alleviating vascular remodelling and VC in CKD. [ABSTRACT FROM AUTHOR]

Objectives: The World Health Organization supports both the screen-and-treat (ST) approach and the screen, triage and treat (STT) approach to cervical cancer screening using high-risk human papillomavirus (hrHPV) testing. For Uganda, the sequence of hrHPV-ST and hrHPV-STT could be similar, with visual inspection with acetic acid (VIA) after positive hrHPV tests in both. To consider potential tradeoffs (overtreatment in ST versus missed cancer cases in STT), we compared hrHPV-STT with VIA triage (STT-VIA), and STT with HPV 16/18 genotyping risk stratification, to hrHPV-ST for Uganda, in terms of overtreatment, cervical cancer incidence, and life years, for the general female population of Uganda. Methods: A microsimulation model of cervical cancer was adapted. Incremental benefit-harm ratios of STT were calculated as ratios of prevented overtreatment to reduced life years, and to increased cancer cases. Additional scenarios with 20% difference in intra- and inter-screening follow-up between ST and STT were modeled. Results: Both STT strategies resulted in life year losses on average compared to ST. STT-VIA prevented more overtreatment but led to increased cervical cancer incidence and life year losses. STT-G-VIA resulted in better harm-benefit ratios and additional costs. With better follow-up, STT prevented overtreatment and improved outcomes. Discussion: For Uganda, the STT approach appears preferrable, if the screening sequences of hrHPV-based ST and STT are similar in practice. While VIA triage alone would reduce overtreatment the most, it could also result in more cancer cases. Risk stratification via genotyping could improve STT. Potential follow-up differences and resource availability should be considered by decision-makers when planning Uganda's hrHPV-based screening strategy. [ABSTRACT FROM AUTHOR]

Background: The use of computed tomography (CT) for attenuation correction (AC) in whole‐body PET/CT can result in a significant contribution to radiation exposure. This can become a limiting factor for reducing considerably the overall radiation exposure of the patient when using the new long axial field of view (LAFOV) PET scanners. However, recent CT technology have introduced features such as the tin (Sn) filter, which can substantially reduce the CT radiation dose. Purpose: The purpose of this study was to investigate the ultra‐low dose CT for attenuation correction using the Sn filter together with other dose reduction options such as tube current (mAs) reduction. We explore the impact of dose reduction in the context of AC‐CT and how it affects PET image quality. Methods: The study evaluated a range of ultra‐low dose CT protocols using five physical phantoms that represented a broad collection of tissue electron densities. A long axial field of view (LAFOV) PET/CT scanner was used to scan all phantoms, applying various CT dose reduction parameters such as reducing tube current (mAs), increasing the pitch value, and applying the Sn filter. The effective dose resulting from the CT scans was determined using the CTDIVol reported by the scanner. Several voxel‐based and volumes of interest (VOI)‐based comparisons were performed to compare the ultra‐low dose CT images, the generated attenuation maps, and corresponding PET images against those images acquired with the standard low dose CT protocol. Finally, two patient datasets were acquired using one of the suggested ultra‐low dose CT settings. Results: By incorporating the Sn filter and adjusting mAs to the lowest available value, the radiation dose in CT images of PBU‐60 phantom was significantly reduced; resulting in an effective dose of nearly 2% compared to the routine low dose CT protocols currently in clinical use. The assessment of PET images using VOI and voxel‐based comparisons indicated relative differences (RD%) of under 6% for mean activity concentration (AC) in the torso phantom and patient dataset and under 8% for a source point in the CIRS phantom. The maximum RD% value of AC was 14% for the point source in the CIRS phantom. Increasing the tube current from 6 mAs to 30 mAs in patients with high BMI, or with arms down, can suppress the photon starvation artifact, whilst still preserving a dose reduction of 90%. Conclusions: Introducing a Sn filter in CT imaging lowers radiation dose by more than 90%. This reduction has minimal effect on PET image quantification at least for patients without Body Mass Index (BMI) higher than 30. Notably, this study results need validation using a larger clinical PET/CT dataset in the future, including patients with higher BMI. [ABSTRACT FROM AUTHOR]