Repeatability of quantitative18F-FLT uptake measurements in solid tumors: an individual patient data multi-center meta-analysis

INTRODUCTION: 3'-deoxy-3'-[18F]fluorothymidine (18F-FLT) positron emission tomography (PET) provides a non-invasive method to assess cellular proliferation and response to antitumor therapy. Quantitative18F-FLT uptake metrics are being used for evaluation of proliferative response in investigational setting, however multi-center repeatability needs to be established. The aim of this study was to determine the repeatability of18F-FLT tumor uptake metrics by re-analyzing individual patient data from previously published reports using the same tumor segmentation method and repeatability metrics across cohorts. METHODS: A systematic search in PubMed, EMBASE.com and the Cochrane Library from inception-October 2016 yielded five18F-FLT repeatability cohorts in solid tumors.18F-FLT avid lesions were delineated using a 50% isocontour adapted for local background on test and retest scans. SUVmax, SUVmean, SUVpeak, proliferative volume and total lesion uptake (TLU) were calculated. Repeatability was assessed using the repeatability coefficient (RC = 1.96 × SD of test-retest differences), linear regression analysis, and the intra-class correlation coefficient (ICC). The impact of different lesion selection criteria was also evaluated. RESULTS: Images from four cohorts containing 30 patients with 52 lesions were obtained and analyzed (ten in breast cancer, nine in head and neck squamous cell carcinoma, and 33 in non-small cell lung cancer patients). A good correlation was found between test-retest data for all18F-FLT uptake metrics (R2 ≥ 0.93; ICC ≥ 0.96). Best repeatability was found for SUVpeak(RC: 23.1%), without significant differences in RC between different SUV metrics. Repeatability of proliferative volume (RC: 36.0%) and TLU (RC: 36.4%) was worse than SUV. Lesion selection methods based on SUVmax ≥ 4.0 improved the repeatability of volumetric metrics (RC: 26-28%), but did not affect the repeatability of SUV metrics. CONCLUSIONS: In multi-center studies, differences ≥ 25% in18F-FLT SUV metrics likely represent a true change in tumor uptake. Larger differences are required for FLT metrics comprising volume estimates when no lesion selection criteria are applied

Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter

A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been successfully built and tested in pion beams. The design of these detectors is presented along with the test results on efficiency, pad multiplicity, stability and reproducibility.Comment: 16 pages, 15 figure

Teachers’ Challenges and Coping Strategies in Conducting Mental Health and Psychosocial Support Activities

Mental Health and Psychosocial Support, or MHPSS, are significant in our wellbeing. During pre-pandemic, some professionals and practitioners were trained to conduct MHPSS. However, teachers are now recognized as providers because of the wide call for the integration of MHPSS in education. Thus, the researcher aimed to explore teachers' experiences conducting MHPSS for students. The study participants are classroom teachers with one to three years of experience in the Department of Education under a teacher induction program and assigned to a school with mental health practitioners like guidance counselors and school nurses. The data is analyzed using the case study model of Meriam and Tisdell. The study revealed the circumstances where students' support, activities conducted, challenges encountered, coping strategies, and responses of the recipients. The study served as an evaluation of the support and intervention in the school setting. Practitioners may use the result of this study to identify the areas where teachers need help the most. Future researchers may examine teachers' experiences assigned to schools without mental health professionals and practitioners to identify more challenges and coping strategies

MICROMEGAS chambers for hadronic calorimetry at a future linear collider

Prototypes of MICROMEGAS chambers, using bulk technology and analog readout, with 1x1cm2 readout segmentation have been built and tested. Measurements in Ar/iC4H10 (95/5) and Ar/CO2 (80/20) are reported. The dependency of the prototypes gas gain versus pressure, gas temperature and amplification gap thickness variations has been measured with an 55Fe source and a method for temperature and pressure correction of data is presented. A stack of four chambers has been tested in 200GeV/c and 7GeV/c muon and pion beams respectively. Measurements of response uniformity, detection efficiency and hit multiplicity are reported. A bulk MICROMEGAS prototype with embedded digital readout electronics has been assembled and tested. The chamber layout and first results are presented

The International Large Detector: Letter of Intent

163 pages, 91 figuresThe International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a push-pull scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account

Vol. 4 No. 2 Summer 2013

Tania de St Croix; liam Kan; Mike newman; Jo Northedge; Mae Shaw; Jo McFarlane; Ross Shoemar

National Security Risks? Uncertainty, Austerity and Other Logics of Risk in the UK government’s National Security Strategy

Risk scholars within Security studies have argued that the concept of security has gone through a fundamental transformation away from a threat-based conceptualisation of defence, urgency and exceptionality to one of preparedness, precautions and prevention of future risks, some of which are calculable, others of which are not. This article explores whether and how the concept of security is changing due to this ‘rise of risk’, through a hermeneutically grounded conceptual and discourse analysis of the United Kingdom government’s national security strategy (NSS) from 1998 to 2011. We ask how risk-security language is employed in the NSS; what factors motivate such discursive shifts; and what, if any, consequences of these shifts can be discerned in UK national security practices. Our aim is twofold: to better understand shifts in the security understandings and policies of UK authorities; and to contribute to the conceptual debate on the significance of the rise of risk as a component of the concept of security