91 research outputs found

    Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

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    Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezĂŒglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklĂ€rt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die PrĂ€valenz fĂŒr synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, wĂ€hrend die PrĂ€valenz mittels PET/ CT-Untersuchung 6,1% betrug. Die SensitivitĂ€t fĂŒr die Panendoskopie betrug 74%, die SpezifitĂ€t 99,7%, der positiv prĂ€diktive Wert 93% und der negativ prĂ€diktive Wert 98%. Die SensitivitĂ€t fĂŒr die PET/CT-Untersuchung betrug 100%, die SpezifitĂ€t 95,7% der positiv prĂ€diktive Wert 59% und der negativ prĂ€diktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie ĂŒberlegen zu sein. Bei bezĂŒglich synchroner Zweitkarzinome unauffĂ€lligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des PrimĂ€rtumors beschrĂ€nkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die DurchfĂŒhrung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar

    The value of 18F-FDG-PET/CT imaging for sinonasal malignant melanoma

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    The aim this study was to evaluate imaging findings using position emission tomography (PET) in combination with computed tomography (CT) and 18F-fluorodeoxyglucose (18F-FDG) in sinonasal malignant melanoma (SNMM) of the head and neck in a retrospective analysis of a consecutive cohort of patients. 18F-FDG-PET/CT examinations were performed for initial staging and compared with CT or magnetic resonance tomography (MRI), and 18F-FDG-PET alone. Medical records were reviewed retrospectively with regard to the location and the size of the tumor. Furthermore, locoregional and distant metastases with a consecutive change in therapy detected by 18F-FDG-PET/CT were assessed. Ten patients suffering from sinonasal malignant melanoma were staged and followed by 18F-FDG-PET/CT imaging. A total of 34 examinations were obtained. 18F-FDG-PET/CT depicted all primary tumors adequately. Aside from one cerebral metastasis all regional and distant metastases were truly identified by using this method. In summary, if available, 18F-FDG-PET/CT is a valuable imaging modality for staging and re-staging sinonasal malignant melanoma to evaluate expansion of the primary tumor, locoregional disease, and distant metastase

    Structural and Superconducting Transitions in Mg_{1-x}Al_{x}B_2

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    From systematic ab initio calculations of the alloy system Mg_{1-x}Al_{x}B_2, we find a strong tendency for the formation of a superstructure characterized by Al-rich layers. We also present a simple model, based on calculated energies and an estimate of the configurational entropy, which suggests that the alloy has two separate concentration regimes of phase separation, with critical points near x = 0.25 and x = 0.75. These results, together with calculations of electronic densities of states in several ionic arrangements, give a qualitative explanation for the observed structural instabilities, as well as the x-dependence of the superconducting T_c for x<0.6.Comment: 4 pp./4 figs.; revisions in responce to Referee comment

    Clinical Events After Deferral of LAD Revascularization Following Physiological Coronary Assessment

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    BACKGROUND Physicians are not always comfortable deferring treatment of a stenosis in the left anterior descending (LAD) artery because of the perception that there is a high risk of major adverse cardiac events (MACE). The authors describe, using the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) trial, MACE rates when LAD lesions are deferred, guided by physiological assessment using fractional flow reserve (FFR) or the instantaneous wave-free ratio (iFR). OBJECTIVES The purpose of this study was to establish the safety of deferring treatment in the LAD using FFR or iFR within the DEFINE-FLAIR trial. METHODS MACE rates at 1 year were compared between groups (iFR and FFR) in patients whose physiological assessment led to LAD lesions being deferred. MACE was defined as a composite of cardiovascular death, myocardial infarction (MI), and unplanned revascularization at 1 year. Patients, and staff performing follow-up, were blinded to whether the decision was made with FFR or iFR. Outcomes were adjusted for age and sex. RESULTS A total of 872 patients had lesions deferred in the LAD (421 guided by FFR, 451 guided by iFR). The event rate with iFR was significantly lower than with FFR (2.44% vs. 5.26%; adjusted HR: 0.46; 95% confidence interval [CI]: 0.22 to 0.95; p = 0.04). This was driven by significantly lower unplanned revascularization with iFR and numerically lower MI (unplanned revascularization: 2.22% iFR vs. 4.99% FFR; adjusted HR: 0.44; 95% CI: 0.21 to 0.93; p = 0.03; MI: 0.44% iFR vs. 2.14% FFR; adjusted HR: 0.23; 95% CI: 0.05 to 1.07; p = 0.06). CONCLUSIONS iFR-guided deferral appears to be safe for patients with LAD lesions. Patients in whom iFR-guided deferral was performed had statistically significantly lower event rates than those with FFR-guided deferral. (c) 2019 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes

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    OBJECTIVES The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p <0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year. (C) 2018 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.Peer reviewe

    ICAR: endoscopic skull‐base surgery

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