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This study assesses the dosimetric effectiveness of the commercial trade-off optimization (TO) module in comparison to iterative optimization for volumetric modulated arc therapy (VMAT) in craniospinal irradiation technique.Fifteen patients who had previously undergone VMAT-based craniospinal irradiation (CSI) using manual optimization (TP) underwent re-optimization with trade-off optimization (MCO). All patients were treated using the Halcyon-E O-ring linear accelerator, with maximum field size of 28×28 cm², a 6MV unflattened beam, and adjacent isocenter field overlap of 10 cm. Plans were compared based on PTV dose coverage (D95%), maximum dose (Dmax), conformity index (CI), heterogeneity index (HI), maximum and mean dose to serial and parallel organs, respectively. Statistical evaluation was conducted using paired sample t-tests. The PTVD95% for TO and MCO plans were 98.0% ± 1.0% and 97.4% ± 0.7%, respectively. In the same sequence, HIs were 1.06 ± 0.01 and 1.07 ± 0.01. CIs for both arms were 0.9 ± 0.0 and its variation was statistically significant (p = 0.027). The differences in dose for bilateral cochlea and left optic nerves were statistically significant (0.022≤ p ≤0.049). The ΔDmax for serial organs and mean dose for parallel organs did not exceed 1%, except for the bilateral optic nerve, mandible, oral cavity, right parotid, and stomach. No parallel organ showed a statistically significant dose variation. Clinically significant reductions in dose were noted for three organs; the average dose reduction in MCO plans for bilateral optic nerves was 3.9%, and for the larynx, it was 8.5%. In this study, trade-off optimization did not demonstrate any significant improvement over the iteratively optimized plans, primarily because the planners were highly skilled and could already generate high-quality plans using iterative optimization alone. However, this finding may not necessarily apply universally to all treatment planners or clinical settings. [ABSTRACT FROM AUTHOR]

To approximate dose-volume histogram (DVH) based quality indicators in volumetric modulated arc therapy (VMAT) planning using multi-criteria optimization (MCO) with a low number of composite optimization parameters. The solution space for VMAT optimization with a low number of composite optimization parameters is approximated by trilinear dose inter- polation and prediction of dose-volume-histogram (DVH) based plan quality indicator values. To assess the approximation quality a diverse dataset of 44 cranial and 18 spine patient geometries was chosen. Optimization results are governed by three composite parameters focusing on target-organ-at-risk- (OAR)-trade-off, overall healthy tissue sparing, and delivery/quality assurance complexity. 21,266 optimized dose distributions were pre-calculated and the numerical values for a choice of 10 DVH points, referred to as plan quality indicators, were stored to serve as ground truth. Using a subset of 8 and 27 pre-calculated optimization results, dose distributions for unknown parameter values were approximated by trilinear interpolation. The resulting quality indicator values were compared to the previously obtained exact solutions. The magnitude of the deviation between exact and approximated values varied largely with respect to patient geometry and the criterion under investigation. Approximation with 27 pre-calculated results yielded lower deviations than approximation with 8 results, at the cost of a higher pre-calculation workload. Solution space approximation via trilinear dose interpolation in VMAT treatment planning governed by composite optimization parameters is possible without further knowledge of the internal implementation of the underlying optimizer. Maximum average deviations between approxi- mation and actual values of characteristic dose quality indicators below 1% (cranial) and 8% (spine) allow for a quick qualitative assessment of the possible solution landscape. [ABSTRACT FROM AUTHOR]

A Pareto Navigation and Visualization (PNaV) tool is presented for interactively constructing a high-dose-rate (HDR) brachytherapy treatment plan by navigating and visualizing the multidimensional Pareto surface. PNaV aims to improve treatment planning time and quality and is generalizable to any number of dose–volume histogram (DVH) and convex dose metrics. Pareto surface visualization and navigation were demonstrated for prostate, breast, and cervix HDR brachytherapy sites. A library of treatment plans was created to span the Pareto surfaces over a 30% range of doses in each of five DVH metrics. The PNaV method, which uses a nonnegative least-squares model to interpolate the library plans, was compared against pure optimization for 11,250 navigated plans using data envelopment analysis. The visualization of the metric trade-offs was accomplished using numerically estimated partial derivatives to plot the local curvature of the Pareto surface. PNaV enables the user to control both the magnitude and direction of the trade-off during navigation. Proof of principle of PNaV was demonstrated using a graphical user interface with visualization tools to enabled rapid plan selection and a quantitative review of metric trade-offs. PNaV produced deliverable plans with DVH metrics within < 0.4%, 0.6%, and 1.1% (95% confidence interval) of the Pareto surface using plan libraries with nominal plan spacing of 10%, 15%, and 30% in each metric dimension, respectively. The interpolation used for the navigation executed in 0.1 s. The fast interpolation allows for quick and efficient exploration of trade-off options by the physician, after an initial preprocessing step to generate the library. Generation, visualization, and navigation of the Pareto surface were validated for brachytherapy treatment planning. The PNaV method enables efficient and informed decision-making for radiotherapy. [ABSTRACT FROM AUTHOR]

• Fabrication of micro-channels using MDPSS pulsed fiber laser micro-engraving process on Si 3 N 4. • The input and output models of the current FLMEP were trained and predicted with the help of the feed-forward ANN model. • MCOs like GRA and RSM were applied to obtain the optimal parametric settings, followed by confirmatory tests from experimentation and the current ANN model. • Dimensional and surface morphology characteristics of channels was scrutinized to divulge the consequences of fiber laser-Si 3 N 4 interaction at microstructural levels. Si 3 N 4 has a unique microstructure and strong atomic bonding, making it a high-performance ceramic (HPC) that can withstand high temperatures without losing strength. Si 3 N 4 ′s natural qualities make it well-suited for technical uses, and it is in high demand for practical biomedical applications. Yet, due to its invulnerability to heat radiation, the fiber laser micro-engraving process (FLMEP) might still leave behind thermic imperfections of poor surface quality. The feasibility of FLMEP requirements, such as pulse frequency, speed, repetition, power, and focal plane position in micro-channel construction, is explored. Furthermore, for the current FLMEP, the input–output models have been trained-predicted-validated with the help of an artificial neural network (ANN). Compared to the experimental result data set, the predictive ANN model based on the 5–25-4 architecture showed the mean square error (MSE = 3.52E−11) and the most potential in boosting confidence, with the slightest error rate. In accession to that, multi-criterion optimization (MCO) was employed by including statistical studies like GRA (grey relational analysis: MCGRAO) and RSM (response surface methodology: MCRSMO) to obtain the optimal predictive solutions. Even though the error values collected via experimental validation suggest that MCGRAO works effectively, the confirmation test results demonstrate that MCRSMO gives better results from the perspective of the optimal solution as per the criteria. Furthermore, the solutions provided by the current MCOs were validated using the ANN model, whose results demonstrate the superiority of the ANN model. Nevertheless, to reveal the implications of fiber laser-Si 3 N 4 interaction at microstructural levels, a reified study on the ablation mechanism followed by dimensional and surface morphology characteristics of channels was scrutinized to divulge the consequences of fiber laser-Si 3 N 4 interaction at microstructural levels. [ABSTRACT FROM AUTHOR]

RaySearch Laboratories is a world leader in the field of advanced software and creator of the RayStation treatment planning system for radiation therapy. The aim with RayStation is to deliver an unmatched user experience and leading functionality. Unique features described here include multiatlas based autosegmentation for contouring, deformable registration with 2 different algorithms, multicriteria optimization, Plan Explorer, fallback planning, ultrafast computation speed, and 4-dimensional (4D) adaptive radiation therapy. RayStation can be used to plan for electrons and photons on traditional linacs, for protons on various delivery systems, and for Accuray's helical TomoTherapy system. This paper describes some of these modalities, with reference to clinical cases and including descriptions of the impact on workflow. [ABSTRACT FROM AUTHOR]

The work investigates the extensive freshwater lacustrine deposits of the Most Formation, which formed in the period between 17.7 Ma and ca. 15.9 Ma, in order to describe climate changes just before the Miocene Climatic Optimum (MCO). The Most Basin, an incipient rift within the European Cenozoic Rift System, exhibited a sedimentary environment that was sufficiently stable to preserve orbital signatures of environmental changes. Changes in the mineral composition of the sediments were characterised in terms of variations in their elemental composition, particularly their Al/Si and K/Ti element ratios and Fe, Sr, and Zr elemental abundances, which were efficiently obtained using X-ray fluorescence spectroscopy with a density of 3–4 samples per metre of core (approximately 15–20 samples per precession cycle). The sediments are distinguished by the presence of distinct and correlated horizons (1–10 cm thick) containing Sr, Ba-rich crandallite, a mineral from the aluminium-phosphate-sulphate (APS) group. Chemo-, magneto-, and cyclostratigraphy were used to correlate eight cores with lengths up to 240 m and to date the sediment; discrepancies at scales of up to two precession cycles (each ca. 20 kyr, typically ~ 4 m per cycle) were observed. The primary age model was based on magnetic polarity analysis (5 reversals) and later refined at the metre scale using cyclostratigraphy. We interpret the onset of the basin-wide lacustrine phase in the Most Basin as being a consequence of the enhanced input of fluvial clastic sediment to the former peat swamps during the high-eccentricity period at 17.7–17.55 Ma, i.e., immediately after the initial decay of the East Antarctic ice sheet according to Levy et al. (2016). The most important environmental change recorded by the lacustrine interval in the Most Basin occurred at 16.44 Ma during an eccentricity maximum and is nearly coeval with further shrinkage of the East Antarctic ice sheet. The second stage of monotonous lacustrine deposition, which exhibited enhanced precession-controlled compositional variability in 16.1–16.0 Ma witnessed the onset of the MCO. Sediments younger than 15.9 Ma are missing due to erosional removal after subsequent basin inversion. The sediments of the Most Formation represent an archive of environmental change in central Europe during the early stages of the MCO and have a temporal resolution ca. 5 kyr. [ABSTRACT FROM AUTHOR]

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Efficacy of inverse planning is becoming increasingly important for advanced radiotherapy techniques. This study’s aims were to validate multicriteria optimization (MCO) in RayStation (v2.4, RaySearch Laboratories, Sweden) against standard intensity-modulated radiation therapy (IMRT) optimization in Oncentra (v4.1, Nucletron BV, the Netherlands) and characterize dose differences due to conversion of navigated MCO plans into deliverable multileaf collimator apertures. Step-and-shoot IMRT plans were created for 10 patients with localized prostate cancer using both standard optimization and MCO. Acceptable standard IMRT plans with minimal average rectal dose were chosen for comparison with deliverable MCO plans. The trade-off was, for the MCO plans, managed through a user interface that permits continuous navigation between fluence-based plans. Navigated MCO plans were made deliverable at incremental steps along a trajectory between maximal target homogeneity and maximal rectal sparing. Dosimetric differences between navigated and deliverable MCO plans were also quantified. MCO plans, chosen as acceptable under navigated and deliverable conditions resulted in similar rectal sparing compared with standard optimization (33.7 ± 1.8 Gy vs 35.5 ± 4.2 Gy, p = 0.117). The dose differences between navigated and deliverable MCO plans increased as higher priority was placed on rectal avoidance. If the best possible deliverable MCO was chosen, a significant reduction in rectal dose was observed in comparison with standard optimization (30.6 ± 1.4 Gy vs 35.5 ± 4.2 Gy, p = 0.047). Improvements were, however, to some extent, at the expense of less conformal dose distributions, which resulted in significantly higher doses to the bladder for 2 of the 3 tolerance levels. In conclusion, similar IMRT plans can be created for patients with prostate cancer using MCO compared with standard optimization. Limitations exist within MCO regarding conversion of navigated plans to deliverable apertures, particularly for plans that emphasize avoidance of critical structures. Minimizing these differences would result in better quality treatments for patients with prostate cancer who were treated with radiotherapy using MCO plans. [ABSTRACT FROM AUTHOR]

• Synthesis of spinels like MCO and MVO for effective conversion of glycerol-to-glycerol carbonate. • Comparative study of transition metals on structural properties and catalytic activity of MgO. • MCO exhibited excellent catalytic activity in production of glycerol carbonate with 98% conversion at mild reaction condition. • Catalyst is easily recoverable and reusable in subsequent cycles of reaction without loss of any activity. • The ideal values of green chemistry metrics like AE, E-factor, PMI etc. confirmed the environmentally friendly nature of designed catalyst. This work reports the reactivity of Mg containing spinels like MgCr 2 O 4 and MgV 2 O 4 for synthesis of glycerol carbonate from bio-glycerol on the basis of their structural, morphological and catalytic properties. Metal oxides having spinel structure exhibit very amazing catalytic properties due to their unique crystal structure and multiple properties like extended surface area, higher basic strength and multiple redox centres. Several characterization techniques like XRD, XPS, TGA, Raman, N 2 adsorption-desorption and SEM-EDX study confirmed the successful synthesis of spinels. Amongst MgCr 2 O 4 (MCO) and MgV 2 O 4 (MVO), MCO proved to be very active and contributed excellent catalytic activity towards glycerol valorisation i.e. 98% conversion of glycerol at mild reaction conditions than that of MVO (82% conversion of glycerol). MCO was highly efficient than that of MVO because of its higher basicity, higher crystallite size which are the fundamental properties for enhancing the catalytic activity of heterogeneous catalysts. From environmental point of view MCO was very flexible, efficient and environmentally friendly catalyst as having ideal E-factor, PMI, and AE values. Overall description concluded that the metal oxide spinels are quite active and enormously applied in glycerol biorefinery in lab scale as well as industrial scale. [Display omitted] [ABSTRACT FROM AUTHOR]

: ObjectivesThe purpose of this study was to create an automated surveillance tool for reporting the incidence, prevalence and processes of care for patients with heart failure.: BackgroundPrevious epidemiologic studies suggest that the increasing prevalence of heart failure is a consequence of improved survival coupled with minimal changes in disease prevention. Developing new, efficient methods of assessing the incidence and prevalence of heart failure could allow continued surveillance of these rates during an era of rapidly changing treatments and health care delivery patterns.: MethodsUsing administrative data sets, we created a definition of heart failure using diagnosis codes. After adjustment for patients leaving our health system or death, we derived the incidence, prevalence and mortality of the population with heart failure from 1989 to 1999.: ResultsA total of 29,686 patients of all ages, 52.6% women and 47.4% men, met the definition of heart failure. Mean ages were 71.1 ± 14.5 for women and 67.7 ± 14.4 for men, p < 0.0001. Race proportions were 50.5% white, 44.6% African American and 4.9% other race. Incidence rates were higher in men and African Americans across all age groups. There was an annual increase in prevalence of 1/1,000 for women and 0.9/1,000 for men, p = 0.001 for both trends.: ConclusionsThrough the feasible and valid use of automated data, we have confirmed a chronic disease epidemic of heart failure manifested primarily by an increase in prevalence over the past decade. Our surveillance system mirrors the results of epidemiologic studies and may be a valid method for monitoring the impact of prevention and treatment programs. [Copyright &y& Elsevier]

In the present report, MnCr 2 O 4 ceramic oxide has been prepared via the solution based self-combustion sol-gel route sintered at 900 °C. The Rietveld refinement of X-ray powder diffraction profile revealed the single-phase normal spinel structure of the ceramic crystallized in a face-centered cubic unit cell with Fd3m space group symmetry. The field emission scanning electron microscopy exposed well distribution of grains separated by grain boundaries as micro-constituents of the sample. Complex impedance spectroscopy deduced the distribution of relaxation times and thermal activation of charge carriers in the frequency and temperature ranges of 70 − 4 × 10 6 Hz and 543 − 643 K, respectively. The depressed semicircular arcs of the Nyquist plot modeled by an equivalent circuit with configuration R G ׀ ׀ C G + R G B ׀ ׀ C G B confirmed the bulk and interface contribution to the electrical response of the material. The correlated barrier hopping conduction addressed the temperature dependence of frequency exponent after simulation of the AC conductivity data by the equation of Jonscher. The complex modulus study identified the electro-active components of the material and determined the dominant role of grains in the conduction mechanism. The analysis of dielectric constant and loss factor stated thermally activated hopping mechanism of charge carriers between Cr2+ and Cr3+ ions at the octahedral sites of the crystal structure. • Manganese Chromite (MnCr 2 O 4) spinel oxide was prepared by wet chemical sol-gel auto-combustion techniques. • The charge conduction mechanism followed correlated barrier hopping transport phenomenon. • Well-conductive grains and poorly conductive grain boundaries with no electrode effects were analyzed by CIS Technique. • Dielectric constant exhibited dispersion in the low frequency region with larger tangent loss which varied directly with temperature. [ABSTRACT FROM AUTHOR]

Intensity-modulated radiation therapy (IMRT) planning is an inherently multi-criteria task. A multi-criteria workflow (MCW) typically passes the following steps: create an optimisation model with multiple criteria, approximate the Pareto frontier, and visualise the generated plans to the decision-maker (DM) for inspection. This interactive plan selection and manipulation allow to create better treatment plans as judged by physicians. However, once an optimisation model is specified, optimisation objectives cannot be modified any more. Thus this fixed model implies that a planner has to guess an appropriate model to begin with. Only after Pareto frontier approximation is calculated, the planner can assess the goodness of the model by exploring the trade-offs. The shortcoming of a MCW becomes apparent when the proposed model fails to generate expected trade-offs and the planner is thus forced to refine the model and repeat the calculations. To circumvent this drawback in the MCW, we propose a local multi-criteria workflow (L-MCW) designed and implemented in a collaboration between Fraunhofer ITWM and Varian Medical Systems. L-MCW enables local exploration around an initial, promising plan. The initial plan is automatically inferred by a knowledge-based algorithm (RapidPlan™). The decision-maker can thus evaluate trade-offs in the most interesting region surrounding the initial plan. Clinical results of the combination of knowledge-based planning and L-MCW with a cohort of Prostate and stereotactic ablative radiotherapy (SABR) Lung cases demonstrate substantially reduced planning time and improved organ-at-risk sparing compared to manual planning. The L-MCW provides an intuitive and flexible mechanism to adapt knowledge-based-planning models to similar, but not identical clinical situations and allows the practitioner to quickly determine and realise the most beneficial trade-offs in a treatment plan. [ABSTRACT FROM AUTHOR]

Introduction Since 2012 in our centers, VMAT with ECLIPSE® Treatment Planning System (TPS) v10 (Varian®) is routinely used to treat patients with breast cancer requiring prophylactic nodal irradiation. In 2015, we acquired the RayStation® TPS v4.7.2 (RAYSEARCH®), with the new dosimetric approach based on MCO concept. The aim of the study is to demonstrate that the use of the MCO reduces learning time by obtaining faster treatment plans respecting the clinical dosimetric constraints commonly published in the literature. Methods This retrospective study included 10 patients, randomly Selected, treated for breast cancer (5 left breasts and 5 right breasts) with nodal irradiation (internal mammary chain, supraclavicular area and axillar third area of Berg when clinically relevant) using VMAT. For each patient, the initial dosimetry was performed using the Eclipse TPS with PRO optimization algorithm V3 and the calculation of the dose with the algorithm “Analytic Anisotropic Algorithm” V10 and 2 mm grid. The prescribed doses were 50 Gy on the mammary gland and from 44 to 50 Gy to the nodes, within 25 fractions. For each patient, a new plan was performed using the RayStation® TPS, maintaining ballistic parameters and the computing grid (2 mm), but with the MCO optimization and the algorithm for dose calculation “Collapsed Cone Convolution”. PTV coverage was evaluated in terms of the homogeneity index (HI), conformity index (CI), DMEAN (Gy), V95% and doses to organs at risks were compared to each other. Results The Homogeneity index was significantly better in the MCO algorithm arm with V95% = 95.39 ± 1.96% versus 85.15 ± 8.48% ( p = 0.005) in the PRO arm. Even finding for the HI index = 0.15 ± 0.03 vs 0.21 ± 0.03 ( p = 0.007)) and HI index = 0.18 ± 0.06 vs 0.24 ± 0.05, respectively for the PTVBreast and PTVNodes. The analysis of doses to organs at risk for the 10 patients shows that there was no significant difference between the two algorithms ( p > 0.05). Conclusions: The MCO algorithm can be used to generate efficiently treatment plans for complex breast cancer. The TPS RayStation with the MCO optimization can quickly and easily obtain comparable or even higher treatment plans than the PRO algorithm. This new TPS was easily and quickly adopted by our team for this location. [ABSTRACT FROM AUTHOR]