189 research outputs found
ESA's Ice Sheets CCI: validation and inter-comparison of surface elevation changes derived from laser and radar altimetry over Jakobshavn Isbræ, Greenland – Round Robin results
In order to increase the understanding of the changing climate, the
European Space Agency has launched the Climate Change Initiative
(ESA CCI), a program which joins scientists and space agencies into
13 projects either affecting or affected by the concurrent
changes. This work is part of the Ice Sheets CCI and four parameters
are to be determined for the Greenland Ice Sheet (GrIS), each
resulting in a dataset made available to the public: Surface
Elevation Changes (SEC), surface velocities, grounding line
locations, and calving front locations. All CCI projects have
completed a so-called Round Robin exercise in which the scientific
community was asked to provide their best estimate of the sought
parameters as well as a feedback sheet describing their work. By
inter-comparing and validating the results, obtained from research
institutions world-wide, it is possible to develop the most optimal
method for determining each parameter. This work describes the SEC
Round Robin and the subsequent conclusions leading to the creation
of a method for determining GrIS SEC values. The participants used
either Envisat radar or ICESat laser altimetry over Jakobshavn
Isbræ drainage basin, and the submissions led to inter-comparisons
of radar vs. altimetry as well as cross-over vs. repeat-track
analyses. Due to the high accuracy of the former and the high
spatial resolution of the latter, a method, which combines the two
techniques will provide the most accurate SEC estimates. The data
supporting the final GrIS analysis stem from the radar altimeters
on-board Envisat, ERS-1 and ERS-2. The accuracy of laser data
exceeds that of radar altimetry; the Round Robin analysis has,
however, proven the latter equally capable of dealing with surface
topography thereby making such data applicable in SEC analyses
extending all the way from the interior ice sheet to margin
regions. This shows good potential for a~future inclusion of ESA
CryoSat-2 and Sentinel-3 radar data in the analysis, and thus for
obtaining reliable SEC estimates throughout the entire GrIS
Individualized early death and long-term survival prediction after stereotactic radiosurgery for brain metastases of non-small cell lung cancer:Two externally validated nomograms
Introduction Commonly used clinical models for survival prediction after stereotactic radiosurgery (SRS) for brain metastases (BMs) are limited by the lack of individual risk scores and disproportionate prognostic groups. In this study, two nomograms were developed to overcome these limitations. Methods 495 patients with BMs of NSCLC treated with SRS for a limited number of BMs in four Dutch radiation oncology centers were identified and divided in a training cohort (n = 214, patients treated in one hospital) and an external validation cohort n = 281, patients treated in three other hospitals). Using the training cohort, nomograms were developed for prediction of early death (<3 months) and long-term survival (>12 months) with prognostic factors for survival. Accuracy of prediction was defined as the area under the curve (AUC) by receiver operating characteristics analysis for prediction of early death and long term survival. The accuracy of the nomograms was also tested in the external validation cohort. Results Prognostic factors for survival were: WHO performance status, presence of extracranial metastases, age, GTV largest BM, and gender. Number of brain metastases and primary tumor control were not prognostic factors for survival. In the external validation cohort, the nomogram predicted early death statistically significantly better (p < 0.05) than the unfavorable groups of the RPA, DS-GPA, GGS, SIR, and Rades 2015 (AUC = 0.70 versus range AUCs = 0.51–0.60 respectively). With an AUC of 0.67, the other nomogram predicted 1 year survival statistically significantly better (p < 0.05) than the favorable groups of four models (range AUCs = 0.57–0.61), except for the SIR (AUC = 0.64, p = 0.34). The models are available on www.predictcancer.org. Conclusion The nomograms predicted early death and long-term survival more accurately than commonly used prognostic scores after SRS for a limited number of BMs of NSCLC. Moreover these nomograms enable individualized probability assessment and are easy into use in routine clinical practice
Sentinel Node Identification Rate and Nodal Involvement in the EORTC 10981-22023 AMAROS Trial
Background
The randomized EORTC 10981-22023 AMAROS trial investigates whether breast cancer patients with a tumor-positive sentinel node biopsy (SNB) are best treated with an axillary lymph node dissection (ALND) or axillary radiotherapy (ART). The aim of the current substudy was to evaluate the identification rate and the nodal involvement.
Methods
The first 2,000 patients participating in the AMAROS trial were evaluated. Associations between the identification rate and technical, patient-, and tumor-related factors were evaluated. The outcome of the SNB procedure and potential further nodal involvement was assessed.
Results
In 65 patients, the sentinel node could not be identified. As a result, the sentinel node identification rate was 97% (1,888 of 1,953). Variables affecting the success rate were age, pathological tumor size, histology, year of accrual, and method of detection. The SNB results of 65% of the patients (n = 1,220) were negative and the patients underwent no further axillary treatment. The SNB results were positive in 34% of the patients (n = 647), including macrometastases (n = 409, 63%), micrometastases (n = 161, 25%), and isolated tumor cells (n = 77, 12%). Further nodal involvement in patients with macrometastases, micrometastases, and isolated tumor cells undergoing an ALND was 41, 18, and 18%, respectively.
Conclusions
With a 97% detection rate in this prospective international multicenter study, the SNB procedure is highly effective, especially when the combined method is used. Further nodal involvement in patients with micrometastases and isolated tumor cells in the sentinel node was similar—both were 18%
Genome-wide analyses of platinum-induced ototoxicity in childhood cancer patients: Results of GO-CAT and United Kingdom MAGIC consortia
: Hearing loss (ototoxicity) is a major adverse effect of cisplatin and carboplatin chemotherapy. The aim of this study is to identify novel genetic variants that play a role in platinum-induced ototoxicity. Therefore, a genome-wide association study was performed in the Genetics of Childhood Cancer Treatment (GO-CAT) cohort (n = 261) and the United Kingdom Molecular Genetics of Adverse Drug Reactions in Children Study (United Kingdom MAGIC) cohort (n = 248). Results of both cohorts were combined in a meta-analysis. In primary analysis, patients with SIOP Boston Ototoxicity Scale grade ≥1 were considered cases, and patients with grade 0 were controls. Variants with a p-value <10-5 were replicated in previously published data by the PanCareLIFE cohort (n = 390). No genome-wide significant associations were found, but variants in TSPAN5, RBBP4P5, AC010090.1 and RNU6-38P were suggestively associated with platinum-induced ototoxicity. The lowest p-value was found for rs7671702 in TSPAN5 (odds ratio 2.0 (95% confidence interval 1.5-2.7), p-value 5.0 × 10-7). None of the associations were significant in the replication cohort, although the effect directions were consistent among all cohorts. Validation and functional understanding of these genetic variants could lead to more insights in the development of platinum-induced ototoxicity
LINAC based stereotactic radiosurgery for multiple brain metastases: guidance for clinical implementation
Introduction: Stereotactic radiosurgery (SRS) is a promising treatment option for patients with multiple brain metastases (BM). Recent technical advances have made LINAC based SRS a patient friendly
technique, allowing for accurate patient positioning and a short treatment time. Since SRS is increasingly being used for patients with multiple BM, it remains essential that SRS be performed with the
highest achievable quality in order to prevent unnecessary complications such as radionecrosis. The
purpo
Successful radiation treatment of anaplastic thyroid carcinoma metastatic to the right cardiac atrium and ventricle in a pacemaker-dependent patient
Anaplastic thyroid carcinoma (ATC) is a rare, aggressive malignancy, which is known to metastasize to the heart. We report a case of a patient with ATC with metastatic involvement of the pacemaker leads within the right atrium and right ventricle. The patient survived external beam radiation treatment to his heart, with a radiographic response to treatment. Cardiac metastases are usually reported on autopsy; to our knowledge, this is the first report of the successful treatment of cardiac metastases encasing the leads of a pacemaker, and of cardiac metastases from ATCs, with a review of the pertinent literature
Reliability of the TekScan MatScan® system for the measurement of plantar forces and pressures during barefoot level walking in healthy adults
<p>Abstract</p> <p>Background</p> <p>Plantar pressure systems are increasingly being used to evaluate foot function in both research settings and in clinical practice. The purpose of this study was to investigate the reliability of the TekScan MatScan<sup>® </sup>system in assessing plantar forces and pressures during barefoot level walking.</p> <p>Methods</p> <p>Thirty participants were assessed for the reliability of measurements taken one week apart for the variables maximum force, peak pressure and average pressure. The following seven regions of the foot were investigated; heel, midfoot, 3<sup>rd</sup>-5<sup>th </sup>metatarsophalangeal joint, 2<sup>nd </sup>metatarsophalangeal joint, 1<sup>st </sup>metatarsophalangeal joint, hallux and the lesser toes.</p> <p>Results</p> <p>Reliability was assessed using both the mean and the median values of three repeated trials. The system displayed moderate to good reliability of mean and median calculations for the three analysed variables across all seven regions, as indicated by intra-class correlation coefficients ranging from 0.44 to 0.95 for the mean and 0.54 to 0.97 for the median, and coefficients of variation ranging from 5 to 20% for the mean and 3 to 23% for the median. Selecting the median value of three repeated trials yielded slightly more reliable results than the mean.</p> <p>Conclusions</p> <p>These findings indicate that the TekScan MatScan<sup>® </sup>system demonstrates generally moderate to good reliability.</p
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