19 research outputs found

    Impact of the COVID-19 crisis on imaging in oncological trials

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    The unprecedented demand for hospital services during the SARS-CoV-2 (COVID-19) pandemic has dramatically reduced the capability for dealing with non-acute health needs, including cancer care [1, 2]. To alleviate burden on health care systems, including imaging and laboratory services, curtailment of non-COVID-19-related research activity has been necessary [3]. Measures that reduce hospital visits have been adopted to limit risk of infection and death, which is critical in a cancer population whose age and immunocompromised status increases their risk [4]. Imaging, however, requires hospital visits and close contact with staff and equipment; both are sources of disease transmission. Equipment used to image COVID-19 cases may retain virus on its surface for days [5, 6] unless disinfected. The need for social distancing and for disinfecting equipment substantially slows imaging workflow and reduces throughput. This article discusses the specific impact of pandemics such as SARS-CoV-2 on imaging in oncological trials

    Standardised lesion segmentation for imaging biomarker quantitation: a consensus recommendation from ESR and EORTC.

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    BACKGROUND: Lesion/tissue segmentation on digital medical images enables biomarker extraction, image-guided therapy delivery, treatment response measurement, and training/validation for developing artificial intelligence algorithms and workflows. To ensure data reproducibility, criteria for standardised segmentation are critical but currently unavailable. METHODS: A modified Delphi process initiated by the European Imaging Biomarker Alliance (EIBALL) of the European Society of Radiology (ESR) and the European Organisation for Research and Treatment of Cancer (EORTC) Imaging Group was undertaken. Three multidisciplinary task forces addressed modality and image acquisition, segmentation methodology itself, and standards and logistics. Devised survey questions were fed via a facilitator to expert participants. The 58 respondents to Round 1 were invited to participate in Rounds 2-4. Subsequent rounds were informed by responses of previous rounds. RESULTS/CONCLUSIONS: Items with ≥ 75% consensus are considered a recommendation. These include system performance certification, thresholds for image signal-to-noise, contrast-to-noise and tumour-to-background ratios, spatial resolution, and artefact levels. Direct, iterative, and machine or deep learning reconstruction methods, use of a mixture of CE marked and verified research tools were agreed and use of specified reference standards and validation processes considered essential. Operator training and refreshment were considered mandatory for clinical trials and clinical research. Items with a 60-74% agreement require reporting (site-specific accreditation for clinical research, minimal pixel number within lesion segmented, use of post-reconstruction algorithms, operator training refreshment for clinical practice). Items with ≤ 60% agreement are outside current recommendations for segmentation (frequency of system performance tests, use of only CE-marked tools, board certification of operators, frequency of operator refresher training). Recommendations by anatomical area are also specified

    Effect of Oppositely Charged Polymer and Dissolution Media on Rheology of Spray-Dried Ionic Complexes

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    The purpose of this research was to address the utility of rheological study in understanding the influence of oppositely charged polymers on release of naproxen sodium encapsulated in chitosan particles. The interaction between oppositely charged κ-carrageenan (κ-Ca) and chitosan leads to relatively higher gel strength, which is proportional to the ability to retard the drug release at acidic pH. The oscillatory tests within the linear viscoelastic range where the stress is proportional to the applied strain were performed on the hydrated sample matrices containing chitosan-naproxen sodium spray-dried complexes and k-Ca or hydroxypropyl methylcellulose (HPMC) in various ratios. It was observed that the effect of pH change on the dynamic moduli in spray-dried complexes containing κ-Ca was much stronger than that with HPMC reflecting presence of strong ionic interaction between κ-Ca and chitosan. The combination of oppositely charged polymers in different ratios proved to be useful in modulating the rheological properties of the hydrated formulations and their release-retarding properties. Dynamic moduli can be used to measure gel strength and are significant for the interpretation of oral sustained release spray-dried complexes

    Chitosan gels for the vaginal delivery of lactic acid: Relevance of formulation parameters to mucoadhesion and release mechanisms

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    The aim of this work was to assess the effect of formulation parameters of a mucoadhesive vaginal gel based on chitosan and lactic acid, and to highlight its release mechanisms. Two molecular weight chitosans were used to prepare gels with 2 lactic acid concentrations. Both chitosan molecular weight and lactic acid concentration had a significant and mutually dependent influence on mucoadhesion, measured on pig vaginal mucosa. Similarly, the lactate release profiles were found to be dependent on lactic acid content and polymer molecular weight
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