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31.
Stefania Clemente Maria Daniela Falco Elisabetta Cagni Cinzia Talamonti Mafalda Boccia Eva Gino Elena Lorenzini Federica Rosica Serenella Russo Alessandro Alparone Daniele Zefiro Christian Fiandra 《The British journal of radiology》2021,94(1119)
Objectives:This multicentric study was carried out to investigate the impact of small field output factors (OFs) inaccuracies on the calculated dose in volumetric arctherapy (VMAT) radiosurgery brain plans.Methods:Nine centres, realised the same five VMAT plans with common planning rules and their specific clinical equipment Linac/treatment planning system commissioned with their OFs measured values (OFbaseline). In order to simulate OFs errors, two new OFs sets were generated for each centre by changing only the OFs values of the smallest field sizes (from 3.2 × 3.2 cm2 to 1 × 1 cm2) with well-defined amounts (positive and negative). Consequently, two virtual machines for each centre were recommissioned using the new OFs and the percentage dose differences ΔD (%) between the baseline plans and the same plans recalculated using the incremented (OFup) and decremented (OFdown) values were evaluated. The ΔD (%) were analysed in terms of planning target volume (PTV) coverage and organs at risk (OARs) sparing at selected dose/volume points.Results:The plans recalculated with OFdown sets resulted in higher variation of doses than baseline within 1.6 and 3.4% to PTVs and OARs respectively; while the plans with OFup sets resulted in lower variation within 1.3% to both PTVs and OARs. Our analysis highlights that OFs variations affect calculated dose depending on the algorithm and on the delivery mode (field jaw/MLC‐defined). The Monte Carlo (MC) algorithm resulted significantly more sensitive to OFs variations than all of the other algorithms.Conclusion:The aim of our study was to evaluate how small fields OFs inaccuracies can affect the dose calculation in VMAT brain radiosurgery treatments plans. It was observed that simulated OFs errors, return dosimetric calculation accuracies within the 3% between concurrent plans analysed in terms of percentage dose differences at selected dose/volume points of the PTV coverage and OARs sparing.Advances in knowledge:First multicentre study involving different Planning/Linacs about undetectable errors in commissioning output factor for small fields. 相似文献
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Angelo Bartoletti Plinio Fabiani Luciano Bagnoli Carlo Cappelletti Marco Cappellini Gino Nappini Roberto Gianni Alessandro Lavacchi Giovanni Maria Santoro 《European heart journal》2008,29(5):618-624
AIMS: To evaluate the prevalence and the characteristics of secondary trauma among patients referred to the emergency department (ED) for a transient loss of consciousness (TLOC). METHODS AND RESULTS: Over a 24 months period, all the patients referred to our ED for a TLOC were evaluated according to the ESC Guidelines on Syncope and enrolled in the study. Among 1253 consecutive patients with TLOC (1114 with a true syncope and 139 with a non-syncopal condition) 365 (29.1%) reported a trauma, in 59 cases (4.7%) severe. The frequency and the characteristics of trauma did not differ among the two main categories of TLOC. Out of 54 patients with syncope and a severe trauma, 20 (37%) had a definite diagnosis after a guidelines-based initial evaluation, and further 17 (31.5%) during the hospital course. Among these latter, carotid sinus syndrome was by far the most common diagnosis. CONCLUSION: Among patients referred to the ED for a TLOC secondary trauma is a common complication, whose characteristics are of little utility to discover the specific cause of the symptom. For older patients with syncope complicated by a severe trauma carotid sinus massage should be the first diagnostic manoeuvre to be undertaken after a non-diagnostic initial evaluation. 相似文献
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Max Wagener Gino Lee Fabio Stallone Tanja Marxer Christian Puelacher Carmela Schumacher Seoung Mann Sou Raphael Twerenbold Tobias Reichlin Thomas Hochgruber Yunus Tanglay Michael Freese Damian Wild Katharina Rentsch Stefan Osswald Michael Zellweger Christian Mueller 《European journal of clinical investigation》2015,45(11):1175-1183
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Kevork Hagopian Alexey A. Tomilov Natalia Tomilova Kyoungmi Kim Sandra L. Taylor Adam K. Lam Gino A. Cortopassi Roger B. McDonald Jon J. Ramsey 《Metabolism: clinical and experimental》2012,61(12):1703-1713
ObjectivesShcKO mice have low body fat and resist weight gain on a high fat diet, indicating that Shc proteins may influence enzymes involved in β-oxidation. To investigate this idea, the activities of β-oxidation and ketone body metabolism enzymes were measured.MethodsThe activities of β-oxidation enzymes (acyl-CoA dehydrogenase, 3-hydroxyacyl-CoA dehydrogenase and ketoacyl-CoA thiolase) in liver and hindlimb skeletal muscle, ketolytic enzymes (acetoacetyl-CoA thiolase, β-hydroxybutyrate dehydrogenase and 3-oxoacid-CoA transferase) in skeletal muscle, and ketogenic enzymes (acetoacetyl-CoA thiolase and β-hydroxybutyrate dehydrogenase) in liver were measured from wild-type and ShcKO mice.ResultsThe activities of β-oxidation enzymes were increased (P < .05) in the ShcKO compared to wild-type mice in the fasted but not the fed state. In contrast, no uniform increases in the ketolytic enzyme activities were observed between ShcKO and wild-type mice. In liver, the activities of ketogenic enzymes were increased (P < .05) in ShcKO compared to wild-type mice in both the fed and fasted states. Levels of phosphorylated hormone sensitive lipase from adipocytes were also increased (P < .05) in fasted ShcKO mice.ConclusionThese studies indicate that the low Shc levels in ShcKO mice result in increased liver and muscle β-oxidation enzyme activities in response to fasting and induce chronic increases in the activity of liver ketogenic enzymes. Decreases in the level of Shc proteins should be considered as possible contributors to the increase in activity of fatty acid oxidation enzymes in response to physiological conditions which increase reliance on fatty acids as a source of energy. 相似文献
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