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VALORE PREDITTIVO DI CRITERI TC DI RISPOSTA DELLE METASTASI EPATICHE DA CANCRO COLON-RETTALE ALLA CHEMIOTERAPIA CITOTOSSICA E BEVACIZUMAB
No full textScopo
Lo scopo dello studio retrospettivo è confrontare diversi criteri TC di risposta alla
chemioterapia citotossica più bevacizumab delle metastasi epatiche da cancro colon-rettale
(mCRC), per determinare quale sia l'indicatore predittivo più precoce del tempo libero da
progressione di malattia (progression-free survival, PFS) in mesi.
Materiale e metodi
Sono stati considerati gli aspetti TC di 103 mCRC target in 65 pazienti trattati con
chemioterapia più bevacizumab all’Istituto Oncologico Veneto, da Marzo 2008 a Gennaio 2013,
e rivalutati da due radiologi indipendenti con i criteri RECIST 1.1, Choi modificati e
morfologici Chun. I pazienti arruolati sono stati sottoposti ad una TC al tempo 0 (t0) e ad
almeno un controllo TC ad intervalli di circa 3 mesi (t1, t2, t3), per la verifica del tempo di
miglior risposta (TBR). L‘analisi della risposta, interpretata come buona (completa o parziale)
o scarsa (stabile o in progressione), è stata correlata con la PFS. È stata valutata anche la
concordanza inter-osservatore con il kappa statistico.
Risultati
Il tempo medio da t0 a t1 è di 3.19 mesi. Il tempo medio tra t0 e TBR è di 3.42 mesi per
RECIST 1.1 e Chun mentre è di 3.19 per Choi. Con RECIST 1.1 32.31% mostra buona risposta
al t1, mentre con Choi 84.62%. I valori percentuali aumentano rispettivamente a 49.23% e
87.69% a TBR, con PFS medio di 12.1 per RECIST 1.1 e 10.8 per Choi. Con Chun, il 67.69%
mostra risposta buona al TBR, con PFS medio di 10.8. Al tempo t1 solo i criteri Choi sono
significativamente correlati con PFS (p=0.0361); tutti i metodi sono significativi al TBR. La
concordanza inter-osservatore è significativa per RECIST 1.1 (K=0.7920) e Choi (K=0.6422).
Conclusioni
I criteri Choi modificati mostrano maggior consistenza nell'individuazione precoce della
risposta dopo trattamento con bevacizumab di mCRC
Short TE and Low Flip Angle VIBE Sequence for Lung Evaluation in PET-MRI
No full textPURPOSE
Low-dose CT in standard PET/CT offers a better morphological lung characterization when compared with Dixon sequences in PET/MRI. Our aim is to improve diagnostic accuracy for lung lesions detection with PET/MRI avoiding a significant increase in the acquisition time, adding a short TE (Echo Time) and low FA (Flip Angle) T1-weighted sequence (gradient-echo volumetric interpolated breath-hold examination [VIBE]) to the standard acquisition protocol.
METHOD AND MATERIALS
We enrolled 21 oncological patients (11 M and 10 F) who underwent both thoracic CT scan and 3T PET-MRI (Siemens Biograph mMR) including lung dedicated short TE and low FA VIBE (inspiration, 3 mm slice thickness, axial plane). Time interval between the two examinations was < 2 weeks. VIBE sequences were retrospectively and independently evaluated by two radiologists for the detection of pulmonary nodules, parenchymal consolidations and dense bands; to assess inter-observer agreement Cohen's kappa coefficient (κ) was calculated. Results were then compared with CT scans findings, considered as the gold standard. Sensitivity and specificity were calculated.
RESULTS
VIBE sensitivity in lung nodules evaluation was 80% (8/10 patients) for nodules >5 mm and 57,1 % (4/7 patients) for nodules 5 mm (κ =0.90, p<0.001), 85% for nodules <= 5 mm (κ=0.44 p<0.005), 90% for dense bands (κ =0.56, p<0.001) and 100% for parenchymal consolidations.
CONCLUSION
VIBE showed high sensitivity in the evaluation of lung nodules > 5 mm; sensitivity was less satisfactory for smaller nodules. This sequence obtained also a very good inter-observer agreement, resulting a very reproducible imaging technique in pulmonary lesion investigation. Considering also the short acquisition time (15-18 s), it seems be reasonable to integrate PET/MRI protocols with a short TE and low FA VIBE, improving its diagnostic performance in lung evaluation.
CLINICAL RELEVANCE/APPLICATION
Short TE and low FA VIBE sequence can improve PET-MRI diagnostic performance in pulmonary lesions detection, without a significant increase in the acquisition time
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
Volumetric histograms-based analysis of apparent diffusion coefficients and standard uptake values for the assessment of pediatric sarcoma at staging: preliminary results of a PET/MRI study
No full textPURPOSE: To assess the relationship between apparent diffusion coefficients (ADC) and standard uptake values (SUV) of pediatric sarcomas at staging by using volumetric histograms analyses.METHODS: Children with histologically proven sarcoma, referring to our tertiary center for a whole-body 18F-FDG PET/MRI for staging and including diffusion weighted imaging in the MRI protocol were investigated. Firstly, turbo inversion recovery magnitude (TIRM) and PET images were resliced and resampled according to the ADC maps. Regions of interests were drawn along tumor margins on TIRM images and then copied on PET and ADC datasets. Pixel-based SUVs and ADCs were collected from the entire volume of each lesion. Mean, median, skewness, and kurtosis of SUVs and ADCs values were computed, and the Pearson correlation coefficient was then applied (for the entire population and for histological subgroups with more than five patients).RESULTS: Thirteen patients met the inclusion criteria (six females; mean age 8.31±6.03years). Histology revealed nine rhabdomyosarcomas, three Ewing sarcomas, and one chondroblastic osteosarcoma. A significant negative correlation between ADCs' and SUVs' mean (rmean=-0.501, P<0.001), median (rmedian=-0.519, P<0,001), and skewness (rskewness=-0.550, P<0.001) emerged for the entire population and for rhabdomyosarcomas (rmean=-0.541, P=0.001, rmedian=-0.597, P<0.001, rskewness=-0.568, P<0.001), whereas a significant positive correlation was found for kurtosis (rkurtosis=0.346, P<0.001, and rkurtosis=0.348, P<0.001 for the entire population and for rhabdomyosarcomas, respectively).CONCLUSION: Our preliminary results demonstrate that, using volumetric histograms, simultaneously collected SUVs and ADCs are dependent biomarkers in pediatric FDG-avid sarcomas. Further studies, on a larger population, are necessary to confirm this evidence and assess its clinical implications
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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