Quantitative DWI as an Early Imaging Biomarker of the Response to Chemoradiation in Esophageal Cancer

For patients diagnosed with stages IIa-IIb esophageal cancer, the current standard of care treatment is tri-modality therapy (TMT), where neoadjuvant chemoradiation (nCRT) is followed by surgical resection. Histopathology of resected tumors reveals that pathological complete response (pCR) is achieved in 20-30% of patients through nCRT alone. Because of the high mortality and morbidity associated with esophagectomy, it may be advantageous for patients exhibiting pCR from nCRT alone to be placed under observation rather than completing their TMT. Therefore, a method for predicting response at an early time-point during nCRT is highly desirable. Conventional methods such as endoscopic ultrasound, re-biopsy, and morphologic imaging are insufficient for this purpose. During nCRT, morphologic changes in tumors are often preceded by changes in the tumor biology. Diffusion Weighed Imaging (DWI) is an MRI modality which is sensitive to microscopic motion of water molecules in tissue. Quantitative DWI provides a measure of the cellular microenvironment which is impacted by cellularity, extra-cellular volume fraction, structure of the extracellular matrix, and cellular membranes. This work sought to investigate if changes in quantitative DWI may be used as an early imaging biomarker for the prediction of response to nCRT in esophageal cancer. DWI scans were performed on a small group of esophageal cancer patients (stages IIa to IIIb) before, at interim, and after completion of their nCRT. Quantitative diffusion parameter maps were estimated for DWI scans using the following models of diffusion: mono-exponential, intra-voxel incoherent motion (IVIM), and kurtosis. Summary measures of quantitative diffusion parameters were extracted from tumor voxels through volumetric contouring. These summary measures were retrospectively compared between histopathologically confirmed groupings of patients as pCR and non-pCR. The study found that the relative change in mean ADC could completely separate groupings of pCR and non-pCR patients (AUC=1) at a cutoff of 27.7%. Measurement by volume contouring was shown to be highly reproducible between readers. This pilot study demonstrates the promise of using DWI for organ sparing approaches after nCRT in esophageal cancer

Mehrdimensionale hydrodynamisch-numerische Modelle im praxisorientierten und operationellen Einsatz

Die Dissertation zeigt die relevanten Grundlagen mehrdimensionaler HN-Modelle. Es wird eine Anleitung für das praktische Arbeiten gegeben und Besonderheiten einzelner Modelltypen werden diskutiert. Auf aktuelle Anforderungen wird eingegangen und Synergieeffekte hybrider bzw. gekoppelter Modellierung werden aufgezeigt. Abgeschlossen wird die Arbeit durch Ausführungen zum operationellen Modelleinsatz sowie die Vorstellung des für das Hochwassermanagement entwickelten Softwaresystems FlowGIS

Vorwort

Titelseite, Inhaltsverzeichnis und Vorwort zum Heft 3

Vorwort

oai:biejournals.de:article/1991Vorwort zum Heft 30 "Freiraum Supervision

Decommissioning the Physics Laboratory, Building 777-10a, at the Savannah River Site (Srs)

SRS recently completed a four-year mission to decommission {approx}250 excess facilities. As part of that effort, SRS decommissioned a 48,000 ft{sup 2} laboratory that housed four low-power test reactors, formerly used by SRS to determine reactor physics. This paper describes and reviews the decommissioning, with a focus on component segmentation and handling (i.e. hazardous material removal, demolition, and waste handling). The paper is intended to be a resource for engineers, planners, and project managers who face similar decommissioning challenges

Session D4: Hybrid Model Approach for Designing Fish Ways - Example Fish Lift System at Baldeney/Ruhr and Fish Way at Geesthacht /Elbe

Abstract: Within the context of designing a fish passage, engineers and planers are provided with numerous standardized constructions methods including the respective assessment criteria to ensure that fish are able to migrate at transverse structures. Due to individual spatial conditions and boundaries, there is a need for special constructions at various locations. Because of lack of design specifications or lack of monitoring experience in the planning stage, the functionality of new systems and construction methods is not proven. Comprehensive functionality tests are therefore to be implemented. At the Baldeney weir an innovative fish lift is currently planned. The required system optimization and the verification of functionality were carried out on behalf of the Ruhrverband in a hybrid model approach, where physical and numerical models as well as ethohydraulic tests were linked. On the basis of a high resolution 3D flow model and a physical model in a 1:3 scale, the flow behaviour within the fish lift and its components was analysed and optimized for different geometrical scenarios taking fish biological limits into account. The optimized geometry of the fish lift system was then placed into a situational similar model with a functional module of the fish lift and studied furthermore by using ethohydraulic tests. With the ethohydraulic tests, all phases of the fish passage (entry, lift passage and exit) could be examined with different fish species at different ages The applied methodology and the effectiveness of the hybrid model approach within the context of planning a fish passage is illustrated by results of the conducted studies for the fish lift system at Baldeney and the fish passage in Geesthach