651 research outputs found
PD-0277: Verification of Acuros XB and analytical anisotropic algorithm (AAA) in heterogeneous media
The year in cardiovascular medicine 2020: arrhythmias
Summary of the progress in arrhythmias in 2020. RACE4 and ALL-IN indicated that integrated nurse-led care improves outcomes in AF patients. The same was reported for early rhythm control therapy and cryoablation as initial AF treatment. Subcutaneous ICD was non-inferior to classical transvenous ICD therapy in PRAETORIAN. One mechanistic study showed that autoantibodies against misexpressed actin, keratin, and connexin-43 proteins create a blood-borne biomarker profile enhancing diagnosis of Brugada syndrome. Another mechanistic study indicated that transseptal LV pacing yields similar improvement in contractility as His bundle pacing whilst being more easy to execute. In PRE-DETERMINE a simple-to-use ECG risk score improved risk prediction in patients with ischemic heart disease possibly enhancing appropriate ICD therapy in high risk patients
PD-0462: Towards dosimetric tracking with adaptive VMAT?
The news and information source for the Henry M. Goldman School of Graduate Dentistr
Stochastic series expansion method for quantum Ising models with arbitrary interactions
A quantum Monte Carlo algorithm for the transverse Ising model with arbitrary
short- or long-range interactions is presented. The algorithm is based on
sampling the diagonal matrix elements of the power series expansion of the
density matrix (stochastic series expansion), and avoids the interaction
summations necessary in conventional methods. In the case of long-range
interactions, the scaling of the computation time with the system size N is
therefore reduced from N^2 to Nln(N). The method is tested on a one-dimensional
ferromagnet in a transverse field, with interactions decaying as 1/r^2.Comment: 9 pages, 5 figure
Evaluation of interplay and organ motion effects by means of 4D dose reconstruction and accumulation
PURPOSE: Pencil beam scanned proton therapy (PBS-PT) treatment quality might be compromised by interplay and motion effects. Via fraction-wise reconstruction of 4D dose distributions and dose accumulation, we assess the clinical relevance of motion related target dose degradation in thoracic cancer patients. METHODS AND MATERIALS: For the ten thoracic patients (Hodgkin lymphoma and non-small cell lung cancer) treated at our proton therapy facility, daily breathing pattern records, treatment delivery log-files and weekly repeated 4DCTs were collected. Patients exhibited point-max target motion of up to 20 mm. They received robustly optimized treatment plans, delivered with five-times rescanning in fractionated regimen. Treatment delivery records were used to reconstruct 4D dose distributions and the accumulated treatment course dose per patient. Fraction-wise target dose degradations were analyzed and the accumulated treatment course dose, representing an estimation of the delivered dose, was compared with the prescribed dose. RESULTS: No clinically relevant loss of target dose homogeneity was found in the fraction-wise reconstructed 4D dose distributions. Overall, in 97% of all reconstructed fraction doses, D98 remained within 5% from the prescription dose. The V95 of accumulated treatment course doses was higher than 99.7% for all ten patients. CONCLUSIONS: 4D dose reconstruction and accumulation enables the clinical estimation of actual exhibited interplay and motion effects. In the patients considered here, the loss of homogeneity caused by interplay and organ motion did not show systematic pattern and smeared out throughout the course of fractionated PBS-PT treatment. Dose degradation due to anatomical changes showed to be more severe and triggered treatment adaptations for five patients
Zeven Limburgse gemeenten stoppen met het gebruik van gif
In Limburg is de laatste decennia veel succes geboekt met het verbeteren van de waterkwaliteit. Dit is met name te danken aan een gestructureerde aanpak bij de sanering van de puntbronnen. Uit waterkwaliteitsonderzoek blijkt dat de meeste oppervlaktewateren echter (nog) niet voldoen aan de normen. Probleemstoffen in oppervlaktewater zijn onder andere chemische onkruidbestrijdingsmiddelen. Met name het gebruik van chemische middelen door de gemeenten leidt tot hoge concentraties in oppervlaktewater, omdat bij regenval de middelen direct of via de riolering afspoelen naar het oppervlaktewater. Om een impuls te geven aan het omschakelen naar een gifvrij beheer van de openbare ruimte in Limburg, hebben het Zuiveringschap Limburg, Provincie Limburg, Rijkswaterstaat directie Limburg en de gemeenten Echt-Susteren, Heerlen, Helden, Horst aan de Maas, Maastricht, Roermond, Roerdalen en Venlo gezamenlijk het initiatief genomen om de omschakeling naar gifvrije onkruidbestrijding door gemeenten nadrukkelijk onder de aandacht brengen. Dit resulteerde in 2001 in het project 'Gifvrije onkruidbestrijding Limburg'. Het vormt één van de speerpuntprojecten van het 'Gemeenschappelijk actieprogramma diffuse bronnen Limburg'. Het project is inmiddels afgerond. In dit artikel staan de belangrijkste succesfactoren, valkuilen en conclusies op een ri
Gut-microbe derived TMAO and its association with more progressed forms of AF:Results from the AF-RISK study
Introduction: The importance of gut microbiome in cardiovascular disease has been increasingly recognized. Trimethylamine N-oxide (TMAO) is a gut microbe-derived metabolite that is associated with cardiovascular disease, including atrial fibrillation (AF). The role of TMAO in clinical AF progression however remains unknown. Methods and results: In this study we measured TMAO and its precursor (betaine, choline, and L- carnitine) levels in 78 patients using plasma samples from patients that participated in the AF-RISK study. 56 patients suffered from paroxysmal AF and 22 had a short history of persistent AF. TMAO levels were significantly higher in patients with persistent AF, as compared to those with paroxysmal AF (median [IQR] 5.65 [4.7–9.6] m/z versus 4.31 [3.2–6.2] m/z, p < 0.05), while precursor levels did not differ. In univariate analysis, we observed that for every unit increase in TMAO, the odds for having persistent AF increased with 0.44 [0.14–0.73], p < 0.01. Conclusion: These results suggest that higher levels of TMAO are associated with more progressed forms of AF. We therefore hypothesize that increased TMAO levels may reflect disease progression in humans. Larger studies are required to validate these preliminary findings.Trial Registration number: Clinicaltrials.gov NCT01510210
Delayed rhythm control of atrial fibrillation may be a cause of failure to prevent recurrences: reasons for change to active antiarrhythmic treatment at the time of the first detected episode
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Expanding the medical physicist curricular and professional programme to include Artificial Intelligence
Purpose: To provide a guideline curriculum related to Artificial Intelligence (AI), for the education and training of European Medical Physicists (MPs). Materials and methods: The proposed curriculum consists of two levels: Basic (introducing MPs to the pillars of knowledge, development and applications of AI, in the context of medical imaging and radiation therapy) and Advanced. Both are common to the subspecialties (diagnostic and interventional radiology, nuclear medicine, and radiation oncology). The learning outcomes of the training are presented as knowledge, skills and competences (KSC approach). Results: For the Basic section, KSCs were stratified in four subsections: (1) Medical imaging analysis and AI Basics; (2) Implementation of AI applications in clinical practice; (3) Big data and enterprise imaging, and (4) Quality, Regulatory and Ethical Issues of AI processes. For the Advanced section instead, a common block was proposed to be further elaborated by each subspecialty core curriculum. The learning outcomes were also translated into a syllabus of a more traditional format, including practical applications. Conclusions: This AI curriculum is the first attempt to create a guideline expanding the current educational framework for Medical Physicists in Europe. It should be considered as a document to top the sub-specialties' curriculums and adapted by national training and regulatory bodies. The proposed educational program can be implemented via the European School of Medical Physics Expert (ESMPE) course modules and - to some extent - also by the national competent EFOMP organizations, to reach widely the medical physicist community in Europe.Peer reviewe
Myocardial dysfunction in long-term breast cancer survivors treated at ages 40-50years
AimsAnthracyclines increase heart failure (HF) risk, but the long-term prevalence of myocardial dysfunction in young breast cancer (BC) survivors is unknown. Early measures of left ventricular myocardial dysfunction are needed to identify BC patients at risk of symptomatic HF. Methods and resultsWithin an established cohort, we studied markers for myocardial dysfunction among 569 women, who were 5-7years (n = 277) or 10-12years (n = 292) after BC treatment at ages 40-50years. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) were assessed by echocardiography. N-terminal pro-brain natriuretic peptide (NT-proBNP) was measured in serum. Associations between patient-related and treatment-related risk factors and myocardial dysfunction were evaluated using linear and logistic regression. Median ages at BC diagnosis and cardiac assessment were 46.7 and 55.5years, respectively. Anthracycline-treated patients (n = 313), compared to the no-anthracycline group (n = 256), more often had decreased LVEF (10% vs. 4%), impaired GLS (34% vs. 27%) and elevated NT-proBNP (23% vs. 8%). GLS and LVEF declined in a linear fashion with increasing cumulative anthracycline dose (GLS: +0.23 and LVEF: -0.40 per cycle of 60mg/m(2); P125ng/L was highest for patients who received 241-300mg/m(2) anthracycline dose compared to the no-anthracycline group (odds ratio: 3.30, 95% confidence interval: 1.83-5.96). ConclusionImpaired GLS and increased NT-proBNP levels are present in a substantial proportion of young BC survivors treated with anthracyclines. Whether this will lead to future cardiac disease needs to be evaluated by longitudinal assessment
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