Τετάρτη, 7 Μαρτίου 2018

New evaluated radioxenon decay data and its implications in nuclear explosion monitoring

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Publication date: Available online 7 March 2018
Source:Journal of Environmental Radioactivity
Author(s): Monica Galan, Martin Kalinowski, Abdelhakim Gheddou, Kassoum Yamba
This work presents the last updated evaluations of the nuclear and decay data of the four radioxenon isotopes of interest for the Comprehensive Nuclear-Test-Ban Treaty (CTBT): Xe-131 m, Xe-133, Xe-133 m and Xe-135. This includes the most recent measured values on the half-lives, gamma emission probabilities (Pγ) and internal conversion coefficients (ICC). The evaluation procedure has been made within the Decay Data Evaluation Project (DDEP) framework and using the latest available versions of nuclear and atomic data evaluation software tools and compilations. The consistency of the evaluations was confirmed by the very close result between the total available energy calculated with the present evaluated data and the tabulated Q-value. The article also analyzes the implications on the variation of the activity ratio calculations from radioxenon monitoring facilities depending on the nuclear database of reference.



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Radionuclide distribution in soil and undecayed vegetative litter samples in a riparian system at the Savannah River Site, SC

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Publication date: Available online 7 March 2018
Source:Journal of Environmental Radioactivity
Author(s): Chieh-Ming Wu, Olorunfemi Adetona, Luke Naeher, Brian J. Viner, Tim Jannik, Allan Hepworth, Eric Doman, Teresa Eddy
The aim of this study is to comprehensively investigate radionuclide concentrations in surface soil and un-decayed vegetative litter along four stream systems (i.e. Fourmile Branch, Lower Three Runs, Pen Branch, and Steel Creek) at the Savannah River Site (SRS), Aiken, South Carolina. Soil and litter samples from systematically spaced 12 pairs (contaminated or uncontaminated) of plots along the four streams were analyzed for 16 distinct radionuclide activities. Lower radionuclide concentrations were observed in soil and litter samples collected along Pen Branch compared to the other 3 streams. The anthropogenic radionuclide with the highest activity was 137Cs in soil (10.6–916.9 Bq/kg) and litter (8.0–222.3 Bq/kg), while the naturally occurring radionuclides possessing the highest concentration in the samples were 40K (33.5–153.7 Bq/kg and 23.1–56.0 Bq/kg in soil and litter respectively) and 226Ra (55.6–159.9 Bq/kg and 30.2–101.8 Bq/kg in soil and litter respectively). A significant difference (p < 0.05) of radionuclide concentrations between paired-plots across four streams was observed for 241Am, 137Cs, 238Pu, 239Pu, and 226Ra in both contaminated and non-contaminated samples. 137Cs and uranium isotopes had the highest litter-to-soil correlation in contaminated (rho = 0.70) and uncontaminated plots (rho = 0.31–0.41), respectively. 90Sr was the only radionuclide with higher radioactive concentrations in litter (12.65–37.56 Bq/kg) compared to soil (1.61–4.79 Bq/kg). The result indicates that 1) historical discharges of anthropogenic 137Cs was the most important contributor of radiation contamination in the riparian environment at SRS, 2) 90Sr was the only radionuclide with higher concentration in litter than in soil, and 3) no apparent pattern in deposition density in soil or litter along downstream was observed for the radionuclides measured in this study.



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Radiocesium contamination of the moss Hypnum plumaeforme caused by the Fukushima Dai-ichi Nuclear Power Plant accident

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Publication date: Available online 7 March 2018
Source:Journal of Environmental Radioactivity
Author(s): Emiko Oguri, Hironori Deguchi
We investigated 134Cs and 137Cs activity concentrations in the common Japanese moss species Hypnum plumaeforme collected from 32 sites within ca. 100 km radius of the Fukushima Dai-ichi Nuclear Power Plant. A total of 32 samples of H. plumaeforme were collected during the field surveys from November 2013 to September 2014. The maximum radiocesium activity concentrations in H. plumaeforme were 60.9 ± 1.8 kBq kg−1 for 134Cs and 123 ± 2.3 kBq kg−1 for 137Cs. The mean value for the 134Cs/137Cs was 1.17 ± 0.05, and the mean Tag value was 0.09 ± 0.13. Positive correlations were obtained between total 134Cs + 137Cs activity concentrations in H. plumaeforme and the air dose rate with a correlation coefficient (r) of 0.55 (P = 0.001), and between 137Cs activity concentration in H. plumaeforme and 137Cs deposition density on soil with r of 0.55 (P = 0.001). These results suggest that the perennial moss species H. plumaeforme could be more suitable and useful as a qualitative indicator for the radiocesium pollution compared to vascular plants spreading over the lowlands including human habitation in Fukushima Prefecture.



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Challenges and complexities in remediation of uranium contaminated soils: A review

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Publication date: Available online 7 March 2018
Source:Journal of Environmental Radioactivity
Author(s): Rajendran Selvakumar, Govindarajan Ramadoss, Mridula P. Menon, Karuppuli Rajendran, Palanisami Thavamani, Ravi Naidu, Mallavarapu Megharaj
Uranium contamination of soil has been a major concern with respect to its toxicity, accumulation in the food chain and persistence in the environment. Owing to these problems, remediation of uranium-contaminated soils has been investigated by various techniques. This review focuses on the challenges and complexities associated with the remediation of uranium-contaminated soil at field level. Therefore, laboratory studies have been excluded from this review. Challenges faced during remediation of uranium-contaminated soil using various techniques such as microbial/phyto/chemical/material based strategies have been discussed with suitable examples. Various factors that have a major influence on uranium decontamination process in soil such as soil type, uranium speciation, the presence of coexisting ions and organics, etc., have been highlighted. This review brings out the significance of the integrated role of various factors which determine the efficiency of the uranium decontamination process.



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The marine kd and water/sediment interaction problem

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Publication date: Available online 7 March 2018
Source:Journal of Environmental Radioactivity
Author(s): R. Periáñez, I. Brovchenko, K.T. Jung, K.O. Kim, V. Maderich
The behavior of marine distribution coefficients is analyzed with the help of numerical experiments and analytical solutions of equations describing kinetic models for uptake/release of radionuclides. The difficulties in measuring true kd in a marine environment perturbed by an external radionuclide source are highlighted. Differences between suspended matter and bed sediment kd are analyzed. The performances of different kinetic models (1-step/2step; single-layer/multi-layer) are studied in model/model and model/experiment comparisons. Implications for the use of models to assess radioactive contamination after an emergency are given; as well as recommendations when kd data are compiled in order to create a useful database.



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Intensity modulated radiotherapy in locally advanced thyroid cancer: Outcomes of a sequential phase I dose-escalation study

To determine the safety and tolerability of dose-escalation using modestly accelerated IMRT in high-risk locally advanced thyroid cancer requiring post-operative radiotherapy, and to report preliminary data on efficacy.

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Treatment of Unruptured, Saccular, Anterior Choroidal Artery Aneurysms with Flow Diversion

Abstract

Background

The region of the brain supplied by the anterior choroidal artery (AChoA) is exquisitely eloquent. Aneurysms arising at or close to the origin of the vessel are not uncommon and damage or occlusion to the vessel can result in devastating consequences. The optimal treatment strategy is yet to be determined.

Objective

We sought to determine the efficacy of flow diversion for the treatment of unruptured AChoA aneurysms.

Method

A retrospective review of our prospectively maintained database was performed to identify all patients with unruptured aneurysms of the AChoA between March 2009 and May 2017. The fundus size, number and type of flow-diverting stent (FD), complications and follow-up data were recorded.

Results

We identified 30 patients (60% female), average age 52.8 ± 10.8 years (range 27–73), with 30 aneurysms. The aneurysms were generally small with a mean fundus diameter of 3.4 mm (range 1–7 mm). Early angiographic follow-up data were available for all patients at which point 15 aneurysms were completely occluded (50%). Delayed angiographic follow-up was available in 24 patients and occlusion was seen in 21 patients (87.5%). Of the patients one developed transient ischemic symptoms after interruption of the antiplatelet medication and another patient had a small embolic infarct with transient symptoms in the periprocedural period.

Conclusion

Flow diversion can be used to successfully treat aneurysms of the AChoA. The treatment carries a high rate of technical and radiological success with a good safety profile.



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Age-Related Changes in Tissue Value Properties in Children: Simultaneous Quantification of Relaxation Times and Proton Density Using Synthetic Magnetic Resonance Imaging

imageObjectives The properties of brain tissue undergo dynamic changes during maturation. T1 relaxation time (T1), T2 relaxation time (T2), and proton density (PD) are now simultaneously quantifiable within a clinically acceptable time, using a synthetic magnetic resonance imaging (MRI) sequence. This study aimed to provide age-specific reference values for T1, T2, and PD in children, using synthetic MRI. Materials and Methods We included 89 children (median age, 18 months; range, 34 weeks of gestational age to 17 years) who underwent quantitative MRI, using a multidynamic, multiecho sequence on 3 T MRI, between December 2015 and November 2016, and had no abnormal MRI/neurologic assessment findings. T1, T2, and PD were simultaneously measured in each of the 22 defined white matter and gray matter regions of interest. The measured values were plotted against age, and a curve fitting model that best explained the age dependence of tissue values was identified. Age-specific regional tissue values were calculated using a fit equation. Results The tissue values of all brain regions, except cortical PD, decreased with increasing age, and the robust negative association was best explained by modified biexponential model of the form Tissue values = T1 × exp (−C1 × age) + T2 × exp (−C2 × age). The quality of fit to the modified biexponential model was high in white matter and deep gray matter (white matter, R2 = 97%–99% [T1], 88%–95% [T2], 88%–97% [PD]; deep gray matter, R2 = 96%–97% [T1], 96% [T2], 49%–88% [PD]; cortex, 70%–83% [T1], 87%–90% [T2], 5%–27% [PD]). The white matter and deep gray matter changed the most dynamically within the first year of life. Conclusions Our study provides age-specific regional reference values, from the neonate to adolescent, of T1, T2, and PD, which could be objective tools for assessment of normal/abnormal brain development using synthetic MRI.

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Increased Delay Between Gadolinium Chelate Administration and T1-Weighted Magnetic Resonance Imaging Acquisition Increases Contrast-Enhancing Tumor Volumes and T1 Intensities in Brain Tumor Patients

imageObjectives The aim of this study was to evaluate the impact of delayed T1-weighted (T1-w) MRI acquisition after gadolinium chelate administration on brain tumor volumes and T1-w intensities. Materials and Methods Fifty-five patients with histologically confirmed, contrast-enhancing intra-axial brain tumors were analyzed in this prospective test-retest study. Patients underwent 2 consecutive 3 T MRI scans (separated by a 1-minute break) during routine follow-up with contrast-enhanced T1 (ceT1-w), T2, and FLAIR acquisition. Macrocyclic gadolinium chelate–based contrast agent was only administered before the first ceT1-w acquisition; median latency to ceT1-w acquisition was 6.72 minutes (IQR, 6.53–6.92) in the first and 16.27 minutes (IQR, 15.49–17.26) in the second scan. Changes in tumor volumes and relative ceT1-w intensities between the 2 acquisitions were quantitatively assessed following semiautomated tumor segmentation (separately for contrast-enhancement [CE], necrosis [NEC], and nonenhancing [NE] tumor). Results Semiautomatically segmented CE tumor volumes were significantly larger in the second acquisition (median +32% [1.2 cm3]; IQR, 16%–62%; P

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Image Quality and Geometric Distortion of Modern Diffusion-Weighted Imaging Sequences in Magnetic Resonance Imaging of the Prostate

imagePurpose The aim of this study was to compare qualitative and quantitative image quality and geometric distortion of 4 magnetic resonance diffusion-weighted imaging (DWI) sequences of the prostate using comparable imaging parameters and similar acquisition times. Methods and Materials Axial T2-weighted turbo spin echo images and axial DWI echo-planar imaging (EPI) sequences, including single-shot spin-echo (ss-EPI), readout-segmented multishot (rs-EPI), selective excitation–reduced field of view (sTX-EPI), and prototype single-shot technique applying slice-specific shimming (iShim-EPI) sequences, were acquired at 3 T in 10 healthy volunteers (mean age, 26.1 ± 3.8 years; body mass index, 23.2 ± 3.0 kg/m2). Two radiologists, blinded to the type of DWI, independently rated DWIs on a 5-point Likert scale regarding subjective image quality features (resolution, demarcation of prostate capsule, zonal anatomy). Interreader agreement was assessed using the intraclass correlation coefficient. Signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) values were assessed separately in the peripheral and transitional zone. For the analysis of geometric distortion, the diameter of the prostate from left to right and from anterior to posterior was measured at the level of the verumontanum on b-1000 DWIs and on T2-weighted turbo spin echo images. Differences were compared using the Wilcoxon rank sum test for qualitative parameters, analysis of variance, and Friedman test for quantitative parameters. A P value of less than 0.05 was considered significant, with correction for multiple comparisons. Results Interreader agreement was good to excellent (intraclass correlation coefficient, 0.71–0.79) for all qualitative features. Subjective image quality regarding "resolution" was significantly better for ss-EPI than rs-EPI (mean Likert score, 4.25 vs 3.8; P = 0.031) and sTX-EPI (4.25 vs 3.3; P = 0.046) and for iShim-EPI as compared with rs-EPI (4.4 vs 3.8; P = 0.031) and sTX-EPI (4.4 vs 3.3; P = 0.047). There was no significant difference regarding capsule demarcation and zonal anatomy. Signal-to-noise ratio was significantly higher in iShim-EPI than sTX-EPI (SNR ± standard deviation [SD], 28.13 ± 8.21 vs 14.96 ± 2.4; P = 0.015). The ADC values were lower for the peripheral zone in the sTX-EPI than in the ss-EPI (ADC ± SD, 1002.94 ± 83.51 vs 1165.05 ± 115.64; P = 0.013) and the rs-EPI (1002.94 ± 83.51 vs 1244.40 ± 89.95; P = 0.0012) and in the transitional zone in the sTX-EPI compared with the rs-EPI (874.50 ± 200.72 vs 1261.47 ± 179.23; P = 0.0021). There were no statistically significant differences in geometric distortion between all DWI sequences. Conclusions Single-shot spin-echo EPI and iShim-EPI showed a tendency toward superior image quality and SNR compared with rs-EPI and sTX-EPI with no significant differences in geometric distortion.

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Ring-Like Enhancement of Hepatocellular Carcinoma in Gadoxetic Acid–Enhanced Multiphasic Hepatic Arterial Phase Imaging With Differential Subsampling With Cartesian Ordering

imageObjective The aim of this study was to evaluate the efficacy of multiphasic hepatic arterial phase (HAP) imaging using DISCO (differential subsampling with Cartesian ordering) in increasing the confidence of diagnosis of hepatocellular carcinoma (HCC). Materials and Methods This retrospective study was approved by the institutional review board, and the requirement for informed patient consent was waived. Consecutive patients (from 2 study periods) with malignant liver nodules were examined by gadoxetic acid–enhanced magnetic resonance imaging using either multiphasic (6 phases; n = 135) or single (n = 230) HAP imaging, which revealed 519 liver nodules other than benign ones (HCC, 497; cholangiocarcinoma, 11; metastases, 10; and malignant lymphoma, 1). All nodules were scored in accordance with the Liver Imaging Reporting and Data System (LI-RADS v2014), with or without consideration of ring-like enhancement in multiphasic HAP images as a major feature. Results In the multiphasic HAP group, 178 of 191 HCCs were scored as LR-3 to LR-5 (3 [1.69%], 85 [47.8%], and 90 [50.6%], respectively). Upon considering ring-like enhancement in multiphasic HAP images as a major feature, 5 more HCCs were scored as LR-5 (95 [53.4%]), which was a significantly more confident diagnosis than that with single HAP images (295 of 306 HCCs scored as LR-3 to LR-5: 13 [4.41%], 147 [49.8%], and 135 [45.8%], respectively; P = 0.0296). There was no significant difference in false-positive or false-negative diagnoses between the multiphasic and single HAP groups (P = 0.8400 and 0.1043, respectively). Conclusions Multiphasic HAP imaging can improve the confidence of diagnosis of HCCs in gadoxetic acid–enhanced magnetic resonance imaging.

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Computed Tomography–Based Imaging of Voxel-Wise Lesion Water Uptake in Ischemic Brain: Relationship Between Density and Direct Volumetry

imageObjectives Net water uptake per volume of brain tissue may be calculated by computed tomography (CT) density, and this imaging biomarker has recently been investigated as a predictor of lesion age in acute stroke. However, the hypothesis that measurements of CT density may be used to quantify net water uptake per volume of infarct lesion has not been validated by direct volumetric measurements so far. The purpose of this study was to (1) develop a theoretical relationship between CT density reduction and net water uptake per volume of ischemic lesions and (2) confirm this relationship by quantitative in vitro and in vivo CT image analysis using direct volumetric measurements. Materials and Methods We developed a theoretical rationale for a linear relationship between net water uptake per volume of ischemic lesions and CT attenuation. The derived relationship between water uptake and CT density was tested in vitro in a set of increasingly diluted iodine solutions with successive CT measurements. Furthermore, the consistency of this relationship was evaluated using human in vivo CT images in a retrospective multicentric cohort. In 50 edematous infarct lesions, net water uptake was determined by direct measurement of the volumetric difference between the ischemic and normal hemisphere and was correlated with net water uptake calculated by ischemic density measurements. Results With regard to in vitro data, water uptake by density measurement was equivalent to direct volumetric measurement (r = 0.99, P

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Potential of Noncontrast Magnetic Resonance Imaging With Diffusion-Weighted Imaging in Characterization of Breast Lesions: Intraindividual Comparison With Dynamic Contrast-Enhanced Magnetic Resonance Imaging

imageObjectives The aim of this study was to assess the potential of noncontrast magnetic resonance imaging (NC-MRI) with diffusion-weighted imaging (DWI) in characterization of breast lesions in comparison to dynamic contrast-enhanced MRI (DCE-MRI) at 3 T. Materials and Methods Consecutive patients with conventional imaging (mammography, ultrasound) BI-RADS 4/5 findings were included in this institutional review board–approved single-center study. All underwent 3 T breast MRI including readout-segmented DWI, DCE, and T2-weighted sequences. Final diagnosis was defined by histopathology or follow-up (>24 months). Two experienced radiologists (R1, R2) independently assigned lesion conspicuity (0 = minimal to 3 = excellent) and BI-RADS scores to NC-MRI (readout-segmented DWI including apparent diffusion coefficient maps) and DCE-MRI (DCE and T2-weighted). Receiver operating characteristics, κ statistics, and visual grading characteristics analysis were applied. Results Sixty-seven malignant and 56 benign lesions were identified in 113 patients (mean age, 54 ± 14 years). Areas under the receiver operating characteristics curves were similar: DCE-MRI: 0.901 (R1), 0.905 (R2); NC-MRI: 0.882 (R1), 0.854 (R2); P > 0.05, respectively. The κ agreement was 0.968 (DCE-MRI) and 0.893 (NC-MRI). Visual grading characteristics analysis revealed superior lesion conspicuity by DCE-MRI (0.661, P

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Effect of Age on High T1 Signal Intensity of the Dentate Nucleus and Globus Pallidus in a Large Population Exposed to Gadodiamide

imageObjective The purpose of this study was to assess the effect of age and number of previous injections of gadodiamide on the signal intensity of unenhanced T1-weighted (T1w) images of the dentate nucleus and globus pallidus in a large population. Materials and Methods A large, single-center retrospective population survey was designed and received institutional review board approval. Between January 2014 and December 2014, T1w signal intensity ratios were obtained from a large population of 2500 consecutive enhanced brain magnetic resonance imaging (MRI) scans. Of these, 1906 MRI scans of patients not previously exposed to any gadolinium (Gd)-based contrast agent were used as control group and were compared with 892 MRI scans of patients with documented prior exposure to intravenous gadodiamide. A quantitative study was conducted to assess the T1w signal intensity of dentate nucleus-to-pons (Dn/Po) and globus pallidus-to-thalamus (Gp/Th) ratios. Multiple regression analysis was used to test the effect of age, time delay, and number of previous Gd-based contrast agent injections as predictor variables of T1w signal intensity ratios. Results In the Gd-exposed patients, multivariate regression analysis showed age (β = −0.285; P

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Pediatric Brain: Gadolinium Deposition in Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted Images Is Dependent on the Type of Contrast Agent

imagePurpose The aim of this study was to identify the signal intensity (SI) changes in the dentate nucleus (DN) and the globus pallidus (GP) on unenhanced T1-weighted magnetic resonance (MR) images after multiple administration of gadolinium-based contrast agents (GBCAs) in children and compare those changes between linear and macrocyclic GBCAs. Materials and Methods This retrospective study was approved by the institutional review board and the requirement for informed consent was waived. We identified 92 children who underwent at least 4 consecutive MR examinations exclusively using either linear GBCA (gadodiamide or gadopentetate dimeglumine, n = 41) or macrocyclic GBCA (gadoterate meglumine, n = 51). Signal intensity ratio changes in the DN to pons and GP to thalamus between the first and last MR examinations were calculated. Results The SI ratios in the linear group increased significantly between the first and last MR examinations (mean difference: DN to pons, 0.0461 ± 0.0480, P

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Magnetic resonance imaging ancillary features used in Liver Imaging Reporting and Data System: An illustrative review.

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Magnetic resonance imaging ancillary features used in Liver Imaging Reporting and Data System: An illustrative review.

World J Radiol. 2018 Feb 28;10(2):9-23

Authors: Campos-Correia D, Cruz J, Matos AP, Figueiredo F, Ramalho M

Abstract
Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. In the adequate clinical context, both multiphasic contrast-enhanced CT and magnetic resonance imaging are non-invasive modalities that allow accurate diagnosis and staging of HCC, although the latter demonstrates greater sensitivity and specificity. Imaging criteria for HCC diagnosis rely on hemodynamic features such as hyperenhancement in the arterial phase and washout in the portal or equilibrium phase. However, imaging performance drops considerably for small (< 20 mm) nodules because their tendency to exhibit atypical enhancement patterns. In order to improve accuracy in the diagnosis and staging of HCC, particularly in cases of atypical nodules, ancillary features, i.e., imaging characteristics that modify the likelihood of HCC, have been described and incorporated into clinical reports, especially in Liver Imaging Reporting and Data System. In this paper, ancillary imaging features will be reviewed and illustrated.

PMID: 29507710 [PubMed]



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Multiparametric MR imaging detects therapy efficacy of radioactive seeds brachytherapy in pancreatic ductal adenocarcinoma xenografts.

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Multiparametric MR imaging detects therapy efficacy of radioactive seeds brachytherapy in pancreatic ductal adenocarcinoma xenografts.

Radiol Med. 2018 Mar 05;:

Authors: Liu Y, Wang Y, Tang W, Jiang M, Li K, Tao X

Abstract
OBJECTIVE: To investigate the therapeutic efficacy of Iodine-125 (125I) seeds brachytherapy to pancreatic ductal adenocarcinoma (PDAC) xenografts via multiparametric magnetic resonance imaging (MRI) analysis.
MATERIALS AND METHODS: Twenty mice were implanted subcutaneously with SW-1990 PDAC xenografts. The tumor-bearing mice were randomly divided into 125I seeds group (n = 10) and blank control group (n = 10). Treatment response was monitored by diffusion-weighted magnetic resonance imaging (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) obtained 1 day before, 14 and 60 days after treatment. Imaging results were correlated with histopathology.
RESULTS: 125I seeds brachytherapy resulted in a significant increase in mean tumor apparent diffusion coefficient (ADC) values compared to the control at 14 and 60 days after treatment (p < 0.05). DCE-MRI showed a significant decrease in the perfusion parameters including Ktrans and Kep (p < 0.05). The mean ADCs within the peripheral region of the tumors were linearly proportional to the mean apoptotic cell density (p = 0.015; Spearman's coefficient = 0.945). The Ktrans and Kep were linearly proportional to microvessel density (MVD) (p = 0.043, 0.047; Spearman's coefficient = 0.891, 0.884).
CONCLUSION: 125I seeds brachytherapy leads to effective inhibition of PDAC cell proliferation, higher degree of necrosis and necroptosis, and lower MVD. Both DW-MRI and DCE-MRI are feasible to monitor a response to 125I seeds brachytherapy in the PDAC xenografts. This paper shows an original project concerning about a possible palliative treatment not only in a murine model (preclinical setting) but also in humans.

PMID: 29508241 [PubMed - as supplied by publisher]



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Racial disparities of differentiated thyroid carcinoma: clinical behavior, treatments, and long-term outcomes.

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Racial disparities of differentiated thyroid carcinoma: clinical behavior, treatments, and long-term outcomes.

World J Surg Oncol. 2018 Mar 05;16(1):45

Authors: Tang J, Kong D, Cui Q, Wang K, Zhang D, Liao X, Gong Y, Wu G

Abstract
BACKGROUND: The incidence of thyroid cancer in black Americans is significantly lower than that in white Americans, and the impact of race on the prognosis of thyroid cancer remains controversial. The purpose of this study was to determine the risk factors for survival in black and white patients and to compare the survival of differentiated thyroid carcinoma subtypes between these two races. We further investigated the association of lymph node and distant metastases with races.
METHODS: This is a retrospective analysis using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. A total of 70,346 cases were included in our study. Patients' demographics and cancer- and treatment-related characteristics were compared between the black and white Americans using chi-square and Fisher's exact tests. For multivariate analysis, Cox proportional hazards regression were used to assess the association between potential risk factors and the survival in black and white patients.
RESULT: Black Americans had a worse overall survival than white Americans (HR = 1.127, P = 0.002). While disease-specific survival (DSS) was comparable, the risk factors for DSS were different between white and black Americans. Black Americans had less lymph node metastasis of classical variant papillary thyroid carcinoma (CPTC, OR = 0.476, P < 0.001) and follicular variant papillary thyroid carcinoma (FVPTC, OR = 0.522, P < 0.001), but not follicular thyroid carcinoma (FTC). However, black Americans with FVPTC, but not CPTC or FTC, had a higher potential of distant metastasis (OR = 1.715, P = 0.026). Furthermore, only white patients with tumor > 2 cm and lymph node metastasis benefited from radioactive iodine.
CONCLUSIONS: The risk factors for DSS were significantly different in white and black patients. The impact of race should be considered in treatment strategy for thyroid cancer.

PMID: 29506526 [PubMed - in process]



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Change in Nephrometry Scoring in Small Renal Masses (<4 cm) on Active Surveillance

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Publication date: Available online 6 March 2018
Source:Academic Radiology
Author(s): Khan H. Mohammed, Zhang Wanzhe, Paterson Catherine, Szewczyk-Bieda Magda, Stephen Lang, Nabi Ghulam
Rationale and ObjectivesPrediction of growth, in particular knowing the possibility of aggressive cancer in small renal masses on active surveillance, remains poorly understood. The study was designed to determine whether serial nephrometry score measurements could predict possibility of aggressive malignancy (grade of cancer) in patients with small renal masses opting for active surveillance initially.Materials and MethodsOne hundred sixteen patients between January 2000 and December 2016 undergoing partial nephrectomy were recruited. Out of these, 97 were analyzed using different nephrometry scoring systems. Measurement of nephrometry scores (Radius of tumors, Exo/Endophytic; Nearness of tumors to the collecting system or sinus; Anterior/posterior; Location in relation to polar lines, Preoperative Aspects and Dimensions Used for Anatomical, Centrality Index) was performed by two researchers. Among the patients opting for partial nephrectomy, 40 were on active surveillance for at least 12 months (mean 32; 12–60 months) before partial nephrectomy. Computed tomography scan images of these patients were retrieved and analyzed including comparison to histopathology.ResultsNephrometry scores measured on serial computed tomography scan images showed a significant correlation between change in score and grade of cancer on multivariate analysis (P value .001). Addition of multivariate analysis to nomogram based on change in size alone did not improve predictive value of area under the curve significantly.ConclusionsChange in nephrometry scoring measurements correlates with grade of cancer in small renal masses but falls short of significantly predicting presence of malignancy or grade of cancer on nomogram in patients opting for active surveillance for small renal masses. At present, this approach may be inadequate for decision-making.



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Overuse of computed tomography for minor head injury in young patients: an analysis of promoting factors

Abstract

Aim

To assess the amount of computed tomography (CT) scans for minor head injury (MHI) performed in young patients in our emergency department (ED), not indicated by National Institute for Health and Clinical Excellence (NICE) and Canadian Computed Tomography Head Rules (CCHR), and to analyze factors contributing to unnecessary examinations. Secondary objectives were to calculate the effective dose, to establish the number of positive CT and to analyze which of the risk factors are correlated with positivity at CT; finally, to calculate sensitivity and specificity of NICE and CCHR in our population.

Materials and methods

We retrospectively evaluated 493 CT scans of patients aged 18–45 years, collecting the following parameters from ED medical records: patient demographics, risk factors indicating the need of brain imaging, trauma mechanism, specialty and seniority of the referring physician. For each CT, the effective dose and the negativity/positivity were assessed.

Results

357/493 (72%) and 347/493 (70%) examinations were not in line with the CCHR and NICE guidelines, respectively. No statistically significant difference between physician specialty (p = 0.29 for CCHR; p = 0.24 for NICE), nor between physician seniority and the amount of inappropriate examinations (p = 0.93 for CCHR, p = 0.97 for NICE) was found but CT scans requested by ED physicians were less inappropriate [p = 0.28, odds ratio (OR) 0.562, CI (95%) 0.336–0.939]. There was no statistically significant correlation between patient age and over-referral (p = 0.74 for NICE, p = 0.93 for CCHR). According to NICE, low speed motor vehicle accident (p = 0.009), motor vehicle accident with high energy impact (p < 0.01) and domestic injuries (p = 0.002) were associated with a higher rate of unwarranted CT; according to CCHR only motor vehicle accident with high energy impact showed a significant correlation with unwarranted CT scan (p < 0.001, OR 44.650, CI 33.123–1469.854). 2% of CT was positive. Multivariate analysis demonstrated that factors significantly associated with CT scan positivity included signs of suspected skull fracture (p < 0.001, OR 20.430, CI 2.727–153.052) and motor vehicle accident with high energy impact (p < 0.001, OR 220.650, CI 33.123–1469.854). In our series, CCHR showed sensitivity of 100%, specificity of 74%; NICE showed sensitivity of 100%, specificity of 72%.

Conclusion

We observed an important overuse of head CT scans in MHI; the main promoting factor for inappropriate was injury mechanism. 2% of head CT were positive, correlating with signs of suspected skull fracture and motor vehicle accident with high energy impact.



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