1,720,962 research outputs found
Sentinel node mapping in melanoma of the back: SPECT/CT helps discriminate "True" and "False" in-transit lymph nodes
No full textA 32-year-old man with melanoma on the right paramedian region of the lower back underwent lymphoscintigraphy for radioguided sentinel node (SN) biopsy. Planar imaging showed the presence of 2 sites of radioactivity accumulation corresponding to an axillary SN and to an "in-transit" SN, located on the right side of the upper trunk. A further "hot spot" placed on the left paramedian region of the lower back was identified by planar lymphoscintigraphy. This last finding could be mistaken for another "in-transit" SN, but SPECT/CT demonstrated it was actually a nonspecific radiopharmaceutical accumulation at the level of the right renal pelvis
Sentinel lymph node mapping in breast cancer: a critical reappraisal of the internal mammary chain issue
No full textAlthough, like the axilla, the internal mammary nodes (IMNs) are a first-echelon nodal drainage site in breast cancer, the importance of their treatment has long been debated. Seminal randomized trials have failed to demonstrate a survival benefit from surgical IMN dissection, and several retrospective studies have shown that IMNs are rarely the first site of recurrence. However, the recent widespread adoption of sentinel lymph node (SLN) biopsy has stimulated a critical reappraisal of such early results. Furthermore, the higher proportion of screening-detected cancers, improved imaging and techniques (i.e., lymphoscintigraphy for radioguided SLN biopsy) make it possible to visualize lymphatic drainage to the IMNs. The virtually systematic application of adjuvant systemic and/or loco-regional radiotherapy encourages re-examination of the significance of IMN metastases. Moreover, randomized trials testing the value of postmastectomy irradiation and a meta-analysis of 78 randomized trials have provided high levels of evidence that local-regional tumor control is associated with long-term survival improvements. This benefit was limited to trials that used systemic chemotherapy, which was not routinely administered in the earlier studies. However, the contribution from IMN treatment is unclear. Lymphoscintigraphic studies have shown that a significant proportion of breast cancers have primary drainage to the IMNs, including approximately 30% of medial tumors and 15% of lateral tumors. In the few studies where IMN biopsy was performed, 20% of sentinel IMNs were metastatic. The risk of IMN involvement is higher in patients with medial tumors and positive axillary nodes. IMN metastasis has prognostic significance, as recognized by its inclusion in the American Joint Committee on Cancer staging criteria, and seems to have similar prognostic importance as axillary nodal involvement. Although routine IMN evaluation might be indicated, it has not been routinely performed, perhaps because IMN drainage with lymphoscintigraphy is more difficult to demonstrate than axillary drainage. This difference is due to technical reasons and not the absence of lymphatics to the IMN. Recent anatomical studies have confirmed a model of breast lymphatic drainage that comprises superficial, deep and perforating systems. The superficial system drains to the axilla, usually to a lymph node posterior to the pectoralis minor muscle. The deep system drains to the axilla and also anastomoses with the perforating system which drains to the IMNs. The perforating system does not connect with the superficial system. The prevalence of IMN drainage tends to reflect the method of lymphoscintigraphy, where peritumoral (deep lymphatic system) injections have a much higher likelihood of IMN drainage than subareolar or subdermal (superficial lymphatic system) injections. The fused SPECT/CT images represent a further technical solution to increase the identification of IMNs and consequently can significantly reduce the false negative rate of sentinel lymph node biopsy. Before mature results from current and future randomized trials assessing the benefit of IMN irradiation become available, lymphoscintigraphy and IMNs biopsy may be used to guide decisions regarding systemic and local-regional treatment. However, even in patients with visualized primary IMN drainage, the potential benefit of treatment should be balanced against the risk of added morbidity
Toward the discovery and development of PSMA targeted inhibitors for nuclear medicine applications
No full textBackground: The rising incidence rate of prostate cancer (PCa) has promoted the development of new diagnostic and therapeutic radiopharmaceuticals during the last decades. Promising im-provements have been achieved in clinical practice using prostate specific membrane antigen (PSMA) labeled agents, including specific antibodies and small molecular weight inhibitors. Focusing on molecular docking studies, this review aims to highlight the progress in the design of PSMA targeted agents for a potential use in nuclear medicine. Results: Although the first development of radiopharmaceuticals able to specifically recognize PSMA was exclusively oriented to macromolecule protein structure such as radiolabeled monoclonal antibodies and derivatives, the isolation of the crystal structure of PSMA served as the trigger for the synthesis and the further evaluation of a variety of low molecular weight inhibitors. Among the nuclear imaging probes and radiotherapeutics that have been developed and tested till today, labeled Glutamate-ureido inhibitors are the most prevalent PSMA-targeting agents for nuclear medicine applications. Conclusion: PSMA represents for researchers the most attractive target for the detection and treatment of patients affected by PCa using nuclear medicine modalities. [99mTc]MIP-1404 is considered the tracer of choice for SPECT imaging and [68Ga]PSMA-11 is the leading diagnostic for PET imaging by general consensus. [18F]DCFPyL and [18F]PSMA-1007 are clearly the emerging PET PSMA candidates for their great potential for a widespread commercial distribution. After paving the way with new imaging tools, academic and industrial R&Ds are now focusing on the development of PSMA inhibitors labeled with alpha or beta minus emitters for a theragnostic application
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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