Purpose
To investigate the performance of various algorithms for deformable image registration (DIR) to propagate regions of interest (ROIs) using multiple commercial platforms.
Methods and materials
...Thirteen institutions participated in the study with six commercial platforms: RayStation (RaySearch Laboratories, Stockholm, Sweden), MIM (Cleveland, OH, USA), VelocityAI and Smart Adapt (Varian Medical Systems, Palo Alto, CA, USA), Mirada XD (Mirada Medical Ltd, Oxford, UK), and ABAS (Elekta AB, Stockholm, Sweden). The DIR algorithms were tested on synthetic images generated with the ImSimQA package (Oncology Systems Limited, Shrewsbury, UK) by applying two specific Deformation Vector Fields (DVF) to real patient data‐sets. Head‐and‐neck (HN), thorax, and pelvis sites were included. The accuracy of the algorithms was assessed by comparing the DIR‐mapped ROIs from each center with those of reference, using the Dice Similarity Coefficient (DSC) and Mean Distance to Conformity (MDC) metrics. Statistical inference on validation results was carried out in order to identify the prognostic factors of DIR performances.
Results
DVF intensity, anatomic site and participating center were significant prognostic factors of DIR performances. Sub‐voxel accuracy was obtained in the HN by all algorithms. Large errors, with MDC ranging up to 6 mm, were observed in low‐contrast regions that underwent significant deformation, such as in the pelvis, or large DVF with strong contrast, such as the clinical tumor volume (CTV) in the lung. Under these conditions, the hybrid DIR algorithms performed significantly better than the free‐form intensity based algorithms and resulted robust against intercenter variability.
Conclusions
The performances of the systems proved to be site specific, depending on the DVF type and the platforms and the procedures used at the various centers. The pelvis was the most challenging site for most of the algorithms, which failed to achieve sub‐voxel accuracy. Improved reproducibility was observed among the centers using the same hybrid registration algorithm.
This article focuses on the development of the study of accounting in the Italian education system between the nineteenth and twentieth centuries. It also focuses on the subsequent formation of a ...scientific and experimental 'forma mentis' that would prepare students for administrative and managerial activities in industry, commerce and public administration. Starting from the second half of the nineteenth century - when the presence of accounting in education was limited to secondary school and implemented with sporadic educational initiatives by private bodies - and covering approximately the 50 years after the unification of Italy, this study analyses, through the lens of Foucault's power-knowledge relationship, the institutional and structural measures adopted by the State to develop the study of accounting in Italy, in the period 1890-1935.
Background
Several experiences in the literature report SBRT as an effective treatment option for medically inoperable early stage non-small cell lung cancer (NSCLC) and oligometastatic disease. The ...optimal fractionation schedules and total dose remain controversial. In this study, we evaluated the safety in terms of toxicity and efficacy of using of 8–10 fractions schedules with Helical Tomotherapy (HT) for primary and metastatic lung lesions.
Methods
Between March 2014 and May 2016, a total of 39 patients (median age 72 years, range 26–91) were treated with HT-SBRT for malignant lung lesions: 22 patients with early stage NSCLC, 17 with oligometastases. Patients received 8–10 fractions with lower daily dose for central and ultracentral lesions. Treatment-related toxicity was evaluated using CTCAE v 4.0 scale. Local control (LC), overall survival (OS) and toxicity rates were prospectively collected.
Results
Median duration of RT was 15 days (range 10–26 days) and no interruption occurred. With a median follow-up of 13 months (range 3–29), we reported one G2 pneumonitis (2.6%) and one G2 chest pain (2.6%); no ≥ G2 esophagitis was registered. Actuarial local control rate was 95.5% both at 12 and 24 months for early stage NSCLC and 92.9% both at 12 and 24 months for metastatic patients. OS rate was 94.4 and 92.3% at 1 year, and 94.4 and 83.9% at 2 years in primary and metastatic group, respectively.
Conclusions
The use of 8–10 fractions schedule HT-SBRT for lung malignancies results in high LC and OS rates with minimal toxicities reported.
The present study reports on the outcomes of our mono-institutional experience of Helical Tomotherapy (HT)-based SRT for brain metastases. The use of this linac is less frequently reported for this ...kind of treatment.
This retrospective study displays a series of patients treated with HT-SRT. The eligibility of using SRT for brain metastases was defined by a Karnofsky performance status of >70, a life expectancy of >6 months, and controlled extra-cranial disease; no SRT was allowed in the case of a number of brain metastases larger than 10. All the cases were discussed by a multidisciplinary board. Toxicity assessments were performed based on CTCAE v5.0. Survival endpoints were assessed using the Kaplan-Meier method, and univariate and multivariate analyses were carried out to identify any potential predictive factor for an improved outcome.
Sixty-four lesions in 37 patients were treated using HT-SRT with a median total dose of 30 Gy in five fractions. The median follow-up was 7 months, and the 1- and 2-year LC rates were both 92.5%. The IPFS rates were and 56.75% and 51.35%. The OS rates were 54% and 40%. The UA showed better IPFS rates significantly related to male sex (
= 0.049), a BED
of ≥42 Gy (
= 0.006), and controlled extracranial disease (
= 0.03); in the MA, a favorable trend towards LC (
= 0.11) and higher BED (
= 0.11) schedules maintained a correlation with improved IPFS rates, although statistical significance was not reached.
HT-based SRT for brain metastases showed safety and efficacy in our monoinstiutional experience. Higher RT doses showed statistical significance for improved outcomes of LC and OS.
It is established that human movements in the vicinity of a permanent static magnetic field, such as those in magnetic resonance imaging (MRI) scanners induce electric fields in the human body; this ...raises potential severe risks of health to radiographers and cleaners exposed routinely to these fields in MRI rooms. The relevant directives and parameters, however, are based on theoretical models, and accurate studies on the simulation of the effects based on human movement data obtained in real conditions are still lacking. Two radiographers and one cleaner, familiar with MRI room activities and these directives, were gait analyzed during the execution of routine job motor tasks at different velocities. Full body motion was recorded in a gait laboratory arranged to reproduce the workspace of a room with an MRI full-body scanner. Body segments were tracked with clusters of at least three markers, from which position and velocity of the centroids were calculated. These were used as input in an established computer physical model able to map the stray field in an MRI room. The spatial peak values of the calculated electric field induced by motion of the head and of the entire body during these tasks, for both the health and sensory effects, were found smaller than the thresholds recommended by the European directives, for both 1.5 T and 3.0 T MRI. These tasks therefore seem to guarantee the safety of MRI room operators according to current professional good practice for exposure risks. Physical modeling and experimental measures of human motion can also support occupational medicine.
This work describes the preliminary analysis of Fricke gels dosimeters
characterized by a new formulation making use of a matrix of polyvinyl
alcohol cross-linked by adding glutaraldehyde and ...analyzed by means of
nuclear magnetic resonance relaxometry. In previous optical studies, these
gels have shown promising dosimetric features in terms of photon sensitivity
and low diffusion of ferric ions produced after irradiation. In this work, we
used a portable nuclear magnetic resonance relaxometer to measure the
relaxation times (which are important for dosimetric applications) of these
gel materials. For this purpose, we performed a study for optimizing the
acquisition parameters with a nuclear magnetic resonance relaxometer. Gel
samples were exposed to clinical 6 MV photons in the dose range between 0 and
20 Gy. Nuclear magnetic resonance relaxometry measurements were per- formed
and the sensitivity to photon beams was measured for various values of the
Fe2+ ion concentration. The analyses pointed out that the MR signal increases
as the Fe2+ content in- creases and the increase is about 75 % when the
concentration of Fe2+ ions is increased from 0.5 mM to 2.5 mM. Furthermore,
the sensitivity improvement achieved with increasing the Fe2+ concentration
is about 60 %. This paper shows that the portable nuclear magnetic resonance
relaxometer used for analysis of porous materials can be used for
characterization of these dosimetric gels and this study can be considered as
the first step for the characterization of these dosimeters which in future
could be used for 3-D dose mapping in clinical applications.
nema
Bank credit loss and ESG performance Bruno, Elena; Iacoviello, Giuseppina; Giannetti, Caterina
Finance research letters,
01/2024, Volume:
59
Journal Article
The aim of the paper is to identify and discuss the suitability of the corporate governance structure of the Cooperative Banking Group (CBG) for preserving the distinctive characteristics of the ...cooperative credit banks (CCBs), such as mutuality and localism, as well as for guaranteeing the levels of capitalization, respecting the overall performance objectives. The analysis methodology uses a case study. The paper provides some reflections on the possible impacts of a radical change in the Italian cooperative credit system following the 2016 reform. The pilot model needs further adjustments in itinere, based on rigorous empirical tests conducted to confer on it the characteristics of universal applicability in the context of the CCBs. The major contribution of the paper is evident from the resulting interpretative process; the analysis conducted on a case study allows us to highlight the importance of the organizational dimension in the CCBs; the performances achieved by these, although with some distinctions throughout the Italian territory, are the result of the adequacy of the governance structures and the corporate control functions, which, even when partly outsourced, are always rigorously inspired by the logic of interconnection among those responsible for the functions themselves
•Linearity of the ESR response of phenol compound exposed to electron beams.•ESR response independent of the for the electron beams energy used.•ESR signal was found to be stable in the first thirty ...days.•Possibility of using this material for ESR electron dosimetry.
There is a need for a sensitive dosimeter using Electron Spin Resonance spectroscopy for use in medical applications, since non-destructive read-out and dose archival could be achieved with this method. This work reports a systematic ESR investigation of IRGANOX® 1076 exposed to clinical electron beams produced by a LINAC used for radiation therapy treatments. Recently, dosimetric features of this material were investigated for irradiation with 60Co γ-photons and neutrons in both pellet and film shape and have been found promising thanks to their high efficiency of radiation-matter energy transfer and radical stability at room temperature. Here the analysis of the dosimetric features of these ESR dosimeters exposed to clinical electron beams at energies of 7, 10 and 14MeV, is described in terms of dependence on microwave power and modulation amplitude, response on dose, dependence on beam type, detection limits, and signal stability after irradiation. The analysis of the ESR signal as function of absorbed dose highlights that the response of this material is linear in the dose range investigated (1–13Gy) and is independent of the beam energy. The minimum detectable dose is found to be smaller than 1Gy. Comparison of electron stopping power values of these dosimeters with those of water and soft tissue highlights equivalence of the response to electron beams in the energy range considered. The signal intensity was monitored for 40days after irradiation and for all energies considered and it shows negligible variations in the first 500h after irradiation whereas after 1100h the signal decay is only of about 4%. In conclusion, it is found that phenolic compounds possess good dosimetric features which make it useful as a sensitive dosimeter for medical applications.
Purpose
The purpose of this paper is to identify, through the preparation of a theoretical framework, the drivers able to highlight the relationships between universities and stakeholders in the area ...of higher education. It also intends to stress the importance of intellectual capital (IC) regarding its contribution to create the quality of higher education.
Design/methodology/approach
The method, through the repetition of different “rounds” of interviews with questionnaires, tends therefore to create situations of comparison, verification and discussion of the different hypotheses prefigured, and then come to a convergence of both scenarios and dates of realization.
Findings
The paper provides a system of indicators for assessing the quality of relationships between stakeholders in the key processes of the universities.
Research limitations/implications
The paper provides a pilot model that needs further adjustments in itinere, based on rigorous empirical tests conducted to confer on it the characteristics of universal applicability within the university context.
Practical implications
The major contribution of the model is evident from the resulting interpretative process, which makes it possible to deduce, from the performance indicators, the strategies put in place by the university to achieve their goals, that is, to prepare any interventions for the optimization of the management of IC which can create the quality of higher education institution.
Originality/value
None of the models presented in the literature details the quality of the relationship between stakeholders in the key processes of the universities and therefore neither investigates the impact produced by them on the performance of the university nor on the way stakeholders perceive the usefulness of the knowledge transmitted or the level of customer satisfaction achieved, as indeed the most recent research on the subject envisages.
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