69 research outputs found

    Guidance on the use of MRI for treatment planning in radiotherapy clinical trials

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    The aim of this article is to propose meaningful guidance covering the technical and safety issues involved when designing or conducting radiotherapy clinical trials that use MRI for treatment planning. The complexity of imaging requirements will depend on the trial aims, design and MRI methods used.The use of MRI within the RT pathway is becoming more prevalent and clinically appropriate as access to MRI increases, treatment planning systems become more versatile and potential indications for MRI-planning in RT are documented. Novel MRI-planning opportunities are often initiated and validated within clinical trials.The guidance in this document is intended to assist researchers designing RT clinical trials involving MRI, so that they may provide sufficient information about the appropriate methods to be used for image acquisition, post-processing and quality assurance such that participating sites complete MRI to consistent standards. It has been produced in collaboration with the National Radiotherapy Trials Quality Assurance Group (RTTQA).As the use of MRI in RT is developed, it is highly recommended for researchers writing clinical trial protocols to include imaging guidance as part of their clinical trial documentation covering the trial-specific requirements for MRI procedures. Many of the considerations and recommendations in this guidance may well apply to MR-guided treatment machines, where clinical trials will be crucial. Similarly, many of these recommendations will apply to the general use of MRI in RT, outside of clinical trials.This document contains a large number of recommendations, not all of which will be relevant to any particular trial. Designers of RT clinical trials must therefore take this into account. They must also use their own judgement as to the appropriate compromise between accessibility of the trial and its technical rigour

    Spanish multicenter real – life registry of retrievable vena cava filters (REFiVeC)

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    Background The treatment of venous thromboembolic disease the treatment of choice is systemic anticoagulation. However, the interruption of the inferior vena cava with filters has been recommended when anticoagulation fails or there is a contraindication. Due to the rising inferior vena cava filter (IVCF) complications, physicians are encouraged to retrieve them when there is no longer recommended. In daily practice, it may be a difficult close follow-up of these patients. In this study, the primary objective was to evaluate the IVCF retrieval rate of all implanted filters in a Spanish registry. Secondary objectives were to analyze the causes of failed retrieval, procedure-related complications, and outcomes at a 12-month follow-up. Results Three hundred fifty-six vena cava filters were implanted in 355 patients. The types of filter were: Gunther Tulip (Cook Medical) 160 (44.9%), Optease (Cordis) 77 (21.6%), Celect (Cook Medical) 49 (13, 7%), Aegisy (Lifetech Scientific) 33 (9.2%), Option ELITE (Argon Medical devices) 16 (4.4%), Denali filter (BD Bard) 11 (3.08%), ALN filter (ALN) 10 (2.8%). Removal was achieved in 274/356 (76,9%). eighty-two (23,1%) IVCF were not retrieved due to the following: 41 (11,5%) patients required ongoing filtration, 24 IVCF (6,7%) patients died before retrieval, and 17 (4,7%) impossibility of retrieval because of a tilted and embedded filter apex. There were no major complications observed. Conclusions The global retrieval rate of IVCF was achieved in 76.9%, and the adjusted retrieval rate was of 94.15% with no major complications. IVCF tilting was associated with failure of filter removal in less than 5% of cases. This study demonstrates that the retrieval procedure of IVCF is controlled by the clinician and not by the interventional radiologist

    Ibero-American Society of Interventionism (SIDI) and the Spanish Society of Vascular and Interventional Radiology (SERVEI) Standard of Practice (SOP) for the management of inferior Vena Cava filters in the treatment of acute venous Thromboembolism

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    Objectives: to present an interventional radiology standard of practice on the use of inferior vena cava filters (IVCFs) in patients with or at risk to develop venous thromboembolism (VTE) from the Iberoamerican Interventional Society (SIDI) and Spanish Vascular and Interventional Radiology Society (SERVEI). Methods: a group of twenty-two interventional radiologist experts, from the SIDI and SERVEI societies, attended online meetings to develop a current clinical practice guideline on the proper indication for the placement and retrieval of IVCFs. A broad review was undertaken to determine the participation of interventional radiologists in the current guidelines and a consensus on inferior vena cava filters. Twenty-two experts from both societies worked on a common draft and received a questionnaire where they had to assess, for IVCF placement, the absolute, relative, and prophylactic indications. The experts voted on the different indications and reasoned their decision. Results: a total of two-hundred-thirty-three articles were reviewed. Interventional radiologists participated in the development of just two of the eight guidelines. The threshold for inclusion was 100% agreement. Three absolute and four relative indications for the IVCF placement were identified. No indications for the prophylactic filter placement reached the threshold. Conclusion: interventional radiologists are highly involved in the management of IVCFs but have limited participation in the development of multidisciplinary clinical practice guidelines

    Innovation Practices in Emerging Economies: Do University Partnerships Matter?

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    Enterprises’ resources and capabilities determine their ability to achieve competitive advantage. In this regard, the key innovation challenges that enterprises face are liabilities associated with their age and size, and the entry barriers imposed on them. In this line, a growing number of enterprises are starting to implement innovation practices in which they employ both internal/external flows of knowledge in order to explore/exploit innovation in collaboration with commercial or scientific agents. Within this context, universities play a significant role providing fertile knowledge-intensive environments to support the exploration and exploitation of innovative and entrepreneurial ideas, especially in emerging economies, where governments have created subsidies to promote enterprise innovation through compulsory university partnerships. Based on these ideas, the purpose of this exploratory research is to provide a better understanding about the role of universities on enterprises’ innovation practices in emerging economies. More concretely, in the context of Mexico, we explored the enterprises’ motivations to collaborate with universities in terms of innovation purposes (exploration and exploitation) or alternatives to access to public funds (compulsory requirement of being involved in a university partnership). Using a sample of 10,167 Mexican enterprises in the 2012 Research and Technological Development Survey collected by the Mexican National Institute of Statistics and Geography, we tested a multinomial regression model. Our results provide insights about the relevant role of universities inside enterprises’ exploratory innovation practices, as well as, in the access of R&D research subsidies

    Intensity-modulated radiation therapy (IMRT) vs. 3D conformal radiotherapy (3DCRT) in locally advanced rectal cancer (LARC): dosimetric comparison and clinical implications

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    <p>Abstract</p> <p>Purpose</p> <p>To compare target dose distribution, comformality, normal tissue avoidance, and irradiated body volume (IBV) in 3DCRT using classic anatomical landmarks (c3DCRT), 3DCRT fitting the PTV (f3DCRT), and intensity-modulated radiation therapy (IMRT) in patients with locally advanced rectal cancer (LARC).</p> <p>Materials and methods</p> <p>Fifteen patients with LARC underwent c3DCRT, f3DCRT, and IMRT planning. Target definition followed the recommendations of the ICRU reports No. 50 and 62. OAR (SB and bladder) constraints were D5 ≀ 50 Gy and Dmax < 55 Gy. PTV dose prescription was defined as PTV95 ≄ 45 Gy and PTVmin ≄ 35 Gy. Target coverage was evaluated with the D95, Dmin, and Dmax. Target dose distribution and comformality was evaluated with the homogeneity indices (HI) and Conformity Index (CI). Normal tissue avoidance of OAR was evaluated with the D5 and V40. IBV at 5 Gy (V5), 10 Gy (V10), and 20 Gy (V20) were calculated.</p> <p>Results</p> <p>The mean GTV95, CTV95, and PTV95 doses were significantly lower for IMRT plans. Target dose distribution was more inhomogeneous after IMRT planning and 3DCRTplans had significantly lower CI. The V40 and D5 values for OAR were significantly reduced in the IMRT plans .V5 was greater for IMRT than for f3DCRT planning (p < 0.05) and V20 was smaller for IMRT plans(p < 0.05).</p> <p>Conclusions</p> <p>IMRT planning improves target conformity and decreases irradiation of the OAR at the expense of increased target heterogeneity. IMRT planning increases the IBV at 5 Gy or less but decreases the IBV at 20 Gy or more.</p

    What is the quality of economic evaluations of non-drug therapies? A systematic review and critical appraisal of economic evaluations of radiotherapy for cancer. Applied Health Economics and Health Policy.

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    Background Breast, cervical and colorectal cancers are the three most frequent cancers in women, while lung, prostate and colorectal cancers are the most frequent in men. Much attention has been given to the economic evaluation of pharmaceuticals for treatment of cancer by the National Institute for Health and Care Excellence (NICE) in the UK and similar authorities internationally, while economic analysis developed for other types of anti-cancer interventions, including radiotherapy and surgery, are less common. Objectives Our objective was to review methods used in published cost-effectiveness studies evaluating radiotherapy for breast, cervical, colorectal, head and neck and prostate cancer, and to compare the economic evaluation methods applied with those defined in the guidelines used by the NICE technology appraisal programme. Methods A systematic search of seven databases (MEDLINE, EMBASE, CDSR, NHSEED, HTA, DARE, EconLit) as well as research registers, the NICE website and conference proceedings was conducted in July 2012. Only economic evaluations of radiotherapy interventions in individuals diagnosed with cancer that included quality-adjusted life-years (QALYs) or life-years (LYs) were included. Included studies were appraised on the basis of satisfying essential, preferred and UK-specific methods requirements, building on the NICE Reference Case for economic evaluations and on other methods guidelines. Results A total of 29 studies satisfied the inclusion criteria (breast 14, colorectal 2, prostate 10, cervical 0, head and neck 3). Only two studies were conducted in the UK (13 in the USA). Among essential methods criteria, the main issue was that only three (10 %) of the studies used clinical-effectiveness estimates identified through systematic review of the literature. Similarly, only eight (28 %) studies sourced health-related quality-of-life data directly from patients with the condition of interest. Other essential criteria (e.g. clear description of comparators, patient group indication and appropriate time horizon) were generally fulfilled, while most of the UK-specific requirements were not met. Conclusion Based on this review there is a dearth of up-to-date, robust evidence on the cost effectiveness of radiotherapy in cancer suitable to support decision making in the UK. Studies selected did not fully satisfy essential method standards currently recommended by NICE

    Leveraging knowledge as a competitive asset? The intensity, performance and structure of universities’ entrepreneurial knowledge exchange activities at a regional level

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    © 2016, The Author(s). Universities are no longer considered to be isolated islands of knowledge, but as institutions increasingly engaged with a range of external partners through entrepreneurial activities. This paper examines the associations between the intensity and performance of knowledge exchange activities undertaken in UK universities with non-academic actors. Drawing on data concerning the structural factors of interactions of universities in the UK with external partners, the paper sheds further light on the nature of these activities through a prism of competitive and uncompetitive regions in order to better understand how universities may be able to leverage both their knowledge and partnerships more effectively as competitive assets. On the one hand, it is found that academics in uncompetitive regions are more intensively engaged in entrepreneurial activities but generate less income from them than their counterparts in competitive regions, suggesting that there are differences in the income-generating capacity of academics across regions. On the other hand, academic knowledge is found to be more strongly bounded within a certain distance in uncompetitive regions whilst geographical distance seems less of a hindrance to academics in competitive regions

    Social progress orientation and innovative entrepreneurship: an international analysis

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