Search

Die sich weltweit ausbreitende COVID-19(„coronavirus disease 2019“)-Pandemie hat sich innerhalb weniger Wochen auch in Deutschland zu einem zunehmenden Problem im Gesundheitssystem und in der gesamten Gesellschaft entwickelt. Da auch die Viszeralmedizin im Fokus steht, sind deutliche Veranderungen im Vorgehen notwendig. Erforderliche Strukturen und Herausforderungen der Viszeralmedizin werden fur notwendige Eingriffe nach Screening und bei SARS(„severe acute respiratory syndrome“)-CoV(„coronavirus“)-2-infizierten Patienten beschrieben und die Anforderungen an die Viszeralchirurgie dargestellt. Hierfur erfolgten eine Analyse der aktuellen und themenbezogenen Literatur und die Erlauterung des Vorgehens im Krankenhaus der Grund- und Regelversorgung am Niederrhein. Bei der Anpassung an die Krisensituation kann die Etablierung eines Systems fur ein Krankenhaus in Deutschland dargestellt werden. Hierfur erfolgten unter anderem die Schaffung eines Corona-Screening-Centers am Haupteingang der Klinik und die Etablierung eines Krisenstabs fur COVID-19. Spezifische interne Leitlinien wurden fur das Vorgehen erstellt, erlautert, durch internationale Studien belegt und mehrfach den jeweiligen Anforderungen der Situation angepasst. Die Krise ist mit deutlicher Verzogerung im Vergleich zu anderen Landern in Deutschland milde verlaufen. Entsprechende Vorbereitungen konnten in vielen Krankenhausern getroffen werden, um moglichst gut vorbereitet zu sein auf schwerkranke SARS-CoV-2-infizierte Patienten auf den Intensivstationen, auf der Isolierstation, im Operationsbereich und in der Endoskopie. Der Schutz der Mitarbeiter und der Patienten ist dabei oberstes Ziel. Letztlich werden wir durch Aufarbeitung der Pandemie auch medizinische Rituale und Angewohnheiten uberdenken mussen.

Nosocomial pneumonia (HAP) is a frequent complication of hospital care. Most data are available on ventilator-associated pneumonia. However, infections on general wards are increasing. A central issue are infections with multidrug resistant (MDR) pathogens which are difficult to treat in the empirical setting potentially leading to inappropriate use of antimicrobial therapy.This guideline update was compiled by an interdisciplinary group on the basis of a systematic literature review. Recommendations are made according to GRADE giving guidance for the diagnosis and treatment of HAP on the basis of quality of evidence and benefit/risk ratio.This guideline has two parts. First an update on epidemiology, spectrum of pathogens and antimicrobials is provided. In the second part recommendations for the management of diagnosis and treatment are given. New recommendations with respect to imaging, diagnosis of nosocomial viral pneumonia and prolonged infusion of antibacterial drugs have been added. The statements to risk factors for infections with MDR pathogens and recommendations for monotherapy vs combination therapy have been actualised. The importance of structured deescalation concepts and limitation of treatment duration is emphasized.Die nosokomiale Pneumonie bleibt eine häufige Komplikation von Krankenhausaufenthalten. Die meisten Daten liegen zur beatmungsassoziierten Pneumonie vor, aber auch auf Normalstationen ist vermehrt mit dieser Erkrankung zu rechnen. Problematisch ist die Zunahme von Infektionen mit multiresistenten Erregern (MRE). Diese erschwert die adäquate Initialtherapie und kann zu unkritischem Einsatz von Breitspektrumantibiotika führen.Das vorliegende Update der S3-Leitlinie von 2012 wurde von einer interdisziplinären Arbeitsgruppe auf der Basis einer systematischen Literaturrecherche erarbeitet. Die Empfehlungen zu Diagnostik und Therapie wurden nach dem GRADE-System abgefasst. Graduierung und Empfehlungsstärke entsprechen der Methodik der Nationalen Versorgungsleitlinien.Die Leitlinie besteht aus zwei Teilen. Der allgemeine Teil vermittelt einen aktuellen Überblick zu Epidemiologie, Erregerspektrum und Therapieoptionen der nosokomialen Pneumonie. Handlungsorientierte Empfehlungen zu Diagnostik und Therapie werden im zweiten Teil abgegeben. Neu in diesem Update sind detailliertere Empfehlungen zur bildgebenden Diagnostik, zur Diagnostik nosokomialer Virusinfektionen sowie zur prolongierten Applikation von Antiinfektiva. Die Angaben zur Bedeutung von Risikofaktoren für Infektionen mit MRE und die Empfehlungen zum Einsatz einer antibakteriellen Kombinationstherapie bei derartigen Infektionen wurden angepasst. Strukturierte Deeskalationskonzepte und eine konsequente Begrenzung der Therapiedauer zur Verminderung des Selektionsdrucks werden besonders betont.

ZusammenfassungDie nosokomiale Pneumonie bleibt eine häufige Komplikation von Krankenhausaufenthalten. Die meisten Daten liegen zur beatmungsassoziierten Pneumonie vor, aber auch auf Normalstationen ist vermehrt mit dieser Erkrankung zu rechnen. Problematisch ist die Zunahme von Infektionen mit multiresistenten Erregern (MRE). Diese erschwert die adäquate Initialtherapie und kann zu unkritischem Einsatz von Breitspektrumantibiotika führen.Das vorliegende Update der S3-Leitlinie von 2012 wurde von einer interdisziplinären Arbeitsgruppe auf der Basis einer systematischen Literaturrecherche erarbeitet. Die Empfehlungen zu Diagnostik und Therapie wurden nach dem GRADE-System abgefasst. Graduierung und Empfehlungsstärke entsprechen der Methodik der Nationalen Versorgungsleitlinien.Die Leitlinie besteht aus zwei Teilen. Der allgemeine Teil vermittelt einen aktuellen Überblick zu Epidemiologie, Erregerspektrum und Therapieoptionen der nosokomialen Pneumonie. Handlungsorientierte Empfehlungen zu Diagnostik und Therapie werden im zweiten Teil abgegeben. Neu in diesem Update sind detailliertere Empfehlungen zur bildgebenden Diagnostik, zur Diagnostik nosokomialer Virusinfektionen sowie zur prolongierten Applikation von Antiinfektiva. Die Angaben zur Bedeutung von Risikofaktoren für Infektionen mit MRE und die Empfehlungen zum Einsatz einer antibakteriellen Kombinationstherapie bei derartigen Infektionen wurden angepasst. Strukturierte Deeskalationskonzepte und eine konsequente Begrenzung der Therapiedauer zur Verminderung des Selektionsdrucks werden besonders betont.

An accessory liver is a rare developmental anomaly. There are two subtypes: the accessory liver lobe (ALL), which is connected to the liver and the true ectopic liver. An accessory liver is usually of no clinical relevance in spite of the very rare cases in which torsion or other complications may cause serious problems. This anomaly should not be misinterpreted as a malignant tumour. We report the case of an accessory liver lobe, located below the left diaphragm, which was misdiagnosed as a metastasis of a known malignant melanoma. The diagnosis ALL was established by a biopsy under guidance of magnetic resonance tomography (MRT). In our opinion, an accessory liver and its appearance should be known, to include this entity in differential diagnosis of perihepatic masses.

SummaryThe aim of the study was to determine the practicability of 18F-FLT in tumours of the head and neck area in terms of visualization, a possible correlation between FLT uptake and proliferation fraction as determined by Ki-67 immunostaining, and if tumoural FLT-uptake has a prognostic meaning, as determined by a correlation to patient survival time. Results were compared to 18F-FDG. Patients, methods: 20 patients with previously untreated lesions of the head and neck area, which were clinically highly suspicious to be malignant, underwent PET scans with 18F-FLT and 18F-FDG, a CT of the head and neck area, and a biopsy. Tumour tracer uptake was determined by standardized uptake value (SUV) normalized to body weight and /non-tumor ratios (T/N). 18F-FDG and 18F-FLT uptake were compared with histopathologic and immunohistochemical results. Results: 19 patients had malignant tumours; one patient had a benign cystadenoma (so called Warthin's tumour) of the parotid gland. One negative lesion turned out to be a malignant T1 stage squamous cell carcinoma in both PET scans, the Warthin's tumour was false positive with 18F-FDG but showed only faint uptake with 18F-FLT, resulting in a sensitivity of 95 % for both tracers. Of all lesions, maximum SUVs of 18F-FLT ranged from 1.53 to 11.70 (mean ± SD 5.81 ± 2.28) those of FDG from 2.63 to 16.50 (mean ± SD 8.91 ± 3.58), p < 0.001. 18F-FLT-T/N ranged from 0.94 to 5.85 (mean ± SD, 3.18 ± 1.21), 18F-FDG-T/N was from 0.92 to 7.50 (mean ± SD, 3.6 ± 1.74), n.s. The mean survival time was 18 months in a maximum follow up time of 36 months. A significant correlation between both PET tracers and survival was detected, but no correlation between the amount of Ki-67 positive cells and FLT. Conclusion: In head and neck cancer in the primary setting 18F-FLT does not provide additional visual information in comparison to 18F-FDG.18F-FLT uptake is inversely correlated with patient survival, as well as 18F-FDG.

Trotz einer Empfehlung der Deutschen Gesellschaft fur Endokrinologie zugunsten des Calcitonin-Screenings wird Calcitonin mit der Frage nach einem medullaren Schilddrusenkarzinom (MTC) bei Patienten mit Schilddrusenknoten in Deutschland mehrheitlich nicht bestimmt. Bei der Fortentwicklung der Empfehlung zum Calcitonin-Screening sollten Assay-spezifische Referenzbereiche und die Geschlechtsspezifitat des Calcitonin- Spiegels (basal und nach Pentagastrin-Stimulation) berucksichtigt und sonomorphologische Einschlusskriterien definiert werden. Unabhangig hiervon besteht eine epidemiologisch unklare Datenlage zur Pravalenz des MTC und eine begrenzte Spezifitat eines basal erhohten Calcitonin-Spiegels bis etwa zum Faktor 5 des oberen Referenzbereichs. Ist eine Niereninsuffizienz, eine bakterielle Infektion sowie eine Alkohol- oder medikamentos bedingte Stimulation des Calcitonins ausgeschlossen, sollte die Hypercalcitoninamie in einer zweiten Messung (ggf. mit einem anderen Assay) bestatigt werden. Vor einer Entscheidung uber eine Thyroidektomie ist der Pentagastrintest notwendig. Ein stimulierter Calcitonin-Spiegel 200 pg/ml ist insbesondere bei Mannern die Abgrenzung einer C-Zell-Hyperplasie gegen ein MTC nicht moglich. Die Etablierung eines sinnvollen Calcitonin-Screenings verlangt die Festlegung auf geeignete sonographische Einschlusskriterien und die Verwendung eines geeigneten Assays mit Validierung der Testergebnisse an einer genugend grosen Patientenzahl. Dazu ist ein kurzes Zeitfenster zwischen Blutentnahme und Verarbeitung der Blutprobe, die Kenntnis der Differenzialdiagnosen, der Medikamenten- und der Alkoholanamnese, die Verfugbarkeit des Pentagastrintests und die Veranlassung einer molekulargenetischen Untersuchung notwendig, die eine Aufklarung des Patienten mit ausreichender Bedenkzeit vor Entscheidung uber eine Operation einschliest. All dies und die Auswahl eines geeigneten Operateurs mit niedriger lokaler Komplikationsrate bei Thyroidektomie mit ggf. Lymph adenektomie sprechen fur die Durchfuhrung eines Calcitonin-Screenings vornehmlich nur an Schilddrusenzentren.

Purpose: Aim of the study was the evaluation of MR imaging of the pelvis for the staging, follow-up and recurrence diagnosis of cervical cancer. Material and Methods: MR imaging of the pelvis was performed in 87 patients with cervical cancer. In 32/87 (36.8%) patients MRI was performed for pretherapeutical staging, in 10/87 (11.5%) for follow-up under radiation therapy and in 45/87 (51.7%) for exclusion of local cancer recurrence. The pretherapeutical results of MRI were compared with the clinical FIGO and the histopathological pT (T)-stage. In follow-up, tumor response was compared by measurement of the maximal diameter and tumor volume. Results: In 15/32 (47%) the FIGO stage for MRI and clinical imaging was the same. MRI diagnosed overstaging in 12/32 (37%) and understaging in 5/32 (16%) of tumors. When the pT-stage was compared, the clinical examination showed better results than MRI. The response categories of the two methods of measurement showed equal categories in 8/10 patients. MRI diagnosed recurrence in 15/56 (33%) patients, which was verified histopathologically. 4/15 (26.7%) recurrences could not be diagnosed by clinical examination. Conclusions: The use of MR imaging is limited in the preoperative staging of cervical cancer. In follow-up it offers an useful diagnostic tool for tumor response under radiation therapy. In the diagnosis of local recurrence MRI is able to find small tumor lesions in the pelvis which could not be diagnosed by clinical examination.

In January 2003 neutron and gamma dose rate measurements at a CASTOR® HAW 20/28 CG were performed by the Bundesamt fur Strahlenschutz at Gorleben. First, commercial dose rate measurement devices were used, then spectral measurements with a Bonner sphere system were made to verify the results. Axial and circumferential dose rate profiles were measured near the cask surface and spectral measurements were performed for some locations. A shielding analysis of the cask was performed with the MCNP Monte Carlo Code with ENDF/B-VI cross section libraries. The cask was modelled 'as built', i.e. with its real inventory, dimensions and material densities and with the same configuration and position as in the storage facility. The average C/E-ratios are 1.3 for neutron dose rates and 1.4 for gamma dose rates. Both the measured and calculated dose rates show the same qualitative trends in the axial and circumferential direction. The spectral measurements show a variation in the spectra across the cask surface. This correlates with the variation found in the C/E-ratios. At cask midheight good agreement between the Bonner sphere system and the commercial device (LB 6411) is found with a 7% lower derived H*(10) dose rate from the Bonner sphere system.

Zeolite α (high-silica LTA), a potential shape-selective catalyst, is synthesized in the presence of tetramethylammonium (TMA) ions. Since TMA+ ions are incapable of forming olefins at low temperature, temperatures in excess of 500 °C are required to thermally decompose them and burn off the carbonaceous deposits, frequently causing damage to the structure. In this paper, the thermal decomposition of zeolitic TMA+ ions is investigated. This work led to a less severe method for removing TMA+ ions by stepwise reaction with ammonia at low temperatures. TMA+ ions located in the supercage can easily be removed at a temperature as low as 250 °C, generating mono- and dimethylamine. Sodalite cage TMA+ ions require a temperature of not more than 400 °C to be degraded. Although this treatment raises the Si/Al ratio somewhat, damage to the structure is minimal. Since the size of the zeolitic pores defines the type of molecules capable of escaping from the zeolite cavities, decomposition of TMA+ ions in NaTMA-Y and NaTMA-high-silica sodalite have been included for comparison.

Die radiologische Bildgebung in der Diagnostik von Lungenmetastasen umfasst zum einen die klassische Rontgenaufnahme und deren Weiterentwicklung in Form der digitalen Tomosynthese und zum anderen die Schnittbildgebungsverfahren CT und MRT. Dabei hat die Computertomographie aufgrund ihrer breiten Verfugbarkeit und ihrer hohen Sensitivitat den hochsten Stellenwert. Eine zunehmend wichtige Rolle im onkologischen Staging, aber auch in der Differenzierung von pulmonalen Herden spielen Hybrid-Bildgebungsverfahren und hier in erster Linie die PET/CT mit unterschiedlichen Tracern. Der Stellenwert der modernsten Modalitat PET/MRT in der Diagnostik von Lungenmetastasen kann gegenwartig noch nicht bestimmt werden.

In this study the potential of predicting critical erosion shear stresses from microphytobenthos chlorophyll a surface concentrations in the upper mm of the sediment surface was investigated. The results should provide a better basis for estimating sediment surface stability on large scales by means of optical remote sensing. To achieve a comprehensive picture, tidal flats in the German and Danish Wadden Sea, which differed in tidal range, wave exposure, sediment type and microphytobenthos composition, were studied. The selection of sampling sites was biased towards water-free and visually undisturbed sediment surfaces. The relationship between critical erosion shear stresses and chlorophyll a concentration was found to be highly site-specific. Most of the variation within the data set cannot be explained by the chlorophyll a concentration and the surface sediment types present. Instead, the data suggest distinct dependencies on other site specific features, such as the intensity of sediment surface reworking, microphytobenthos assemblage composition and the endobenthic macrofauna present. It is concluded that to estimate critical erosion shear stresses from chlorophyll a concentration by means of optical remote sensing techniques requires extensive and repeated site specific calibrations since their validity is limited by the patchy and sporadic occurrence of some of the determinant parameters.

A basis to monitor erosion shear stress of tidal flat surfaces by means of optical remote sensing has been developed. Erosion shear stress and corresponding bio-geochemical parameters of different tidal flats were measured during five years in the Sylt/Romo Bight in Germany. A significant dependence between the erosion shear stress and the benthic diatom chlorophylla concentration in the uppermost 1 mm layer was found for the muddy areas. This dependence decreases with decreasing grain-size fraction

The primary carcinoma of the fallopian tube is a rare disease with a bad prognosis. In a patient suffering from this disease a floating, intracardial structure occurred during systemic chemotherapy. An MRI was used to distinguish between metastasis and thrombus. The size of the thrombus decreased under anticoagulation und chemotherapy. The case showed that imaging methods like CT and MRI are useful in differential diagnosis between thrombus and metastasis.

Endobronchial ultrasound-guided transbronchial fine needle aspiration (EBUS-TBNA) has become an important tool in the diagnosis and staging of malignant tumors of the lungs and mediastinum. Rapid on-site evaluation (ROSE) denotes a cytomorphological diagnostic procedure that allows assessment of the adequacy and accuracy of the material obtained during bronchoscopy within a few minutes in or near the bronchoscopy suite (on-site) using a quick staining of smears. This results in a significant decrease in the number of repeated bronchoscopy procedures required to recover an adequate biopsy sample and is therefore both time and cost effective. The obtained material can be further assessed as conventional cytological specimens or alternatively using the thin-prep technique for definitive cytopathology diagnosis and/or embedded in paraffin for immunohistochemical or molecular analyses such as DNA sequencing or flow cytometry.

HISTORY AND CLINICAL SYMPTOMS: A 58-year-old man was admitted to our hospital with acute chest pain and subfebrile temperatures. Two years ago, endovascular aortic stent-graft placement had been performed for acute type B aortic dissection complicated by malperfusion syndrome.CT angiography showed a discrete soft-tissue attenuation mass between the aorta and esophagus. The patient developed progressive swallow disorder and esophago-gastro-duodenoscopy demonstrated deep esophageal ulcerations at the level of the implanted aortic stent-graft. Intravenous treatment with broad spectrum antibiotics was started. The FDG-PET/CT scan showed increased FDG uptake and air entrapment in the affected region establishing the diagnosis of aortoesophageal fistula formation.Given the generally poor condition of the patient and the high risk of any aggressive surgical intervention, a new limited surgical approach was chosen consisting of open transthoracic esophageal resection, blind closure of the stomach and cervical esophagostomy. A percutaneous endoscopic gastrostomy tube was placed. After three months, esophageal continuity was restored by retrosternal colon interposition. The presented therapeutic management resulted in a full recovery of the patient.Aortoesophageal fistula is a rare complication of thoracic aortic stent-graft placement. Patient may present with unspecific symptoms such as fever and rised inflammatory markers, but may also present with massive upper gastrointestinal bleeding. The herein presented limited therapy with esophageal resection represents a promising to the otherwise difficult therapy of aortoesophageal fistula.

Traumatic injury of supra-aortic vessels remains a challenge in the initial diagnostics of severely injured patients. The presented prospective study analyzed the impact of multislice computed tomography angiography (CTA) as the primary diagnostic method.Patients with the following criteria were included and screened for a dissection of the supra-aortic vessels: a) admission directly from the scene, b) resuscitation room treatment indicated by the official criteria of the DGU (German Society for the Surgery of Trauma), c) suspected blunt trauma to head or trunk as well as d) age over 16 years.During a period of 18 months 374 patients were treated for blunt trauma in the resuscitation room. In 176 cases CTA of the supra-aortic vessels was performed and pathological findings were observed in 16 patients. In 4 cases (2%) a traumatic dissection of supra-aortal vessels was diagnosed and confirmed by magnetic resonance imaging (MRI). All patients received heparin in a PTT effective dosage for 2 weeks and after rehabilitation there were no neurologic deficits.Traumatic supra-aortic dissection was found in 2% of cases in the presented study group. The mechanisms of injury were not distinct in this group. Essentially MSCT angiography screening was demonstrated to be a safe diagnostic tool.

The pore structures of carbon materials — char (oxicoke), coal coke, and pitch coke — were modified by controlled gasification. The factors varied were CO2 and H2O atmosphere, temperature, and partial pressure up to 40 bar. Additional tests with H2 were also carried out. For char it was found that steam gasification produces a less microporous structure and distinctly lower BET surface areas than gasification in CO2. A reverse effect was found for coke and pitch coke. In general the BET surface area decreases systematically with increasing gasification rate i.e. increasing temperature and/or pressure. On the other hand the magnitude of the resulting BET surface area depends strongly on the precursor material and can be increased considerably by preoxidation of the parent coal. It is shown quantitatively how the individual factors influence the development of microporosity and how sintering effects may influence the structural development.

An accessory liver is a rare developmental anomaly. There are two subtypes: the accessory liver lobe (ALL), which is connected to the liver and the true ectopic liver. An accessory liver is usually of no clinical relevance in spite of the very rare cases in which torsion or other complications may cause serious problems. This anomaly should not be misinterpreted as a malignant tumour. We report the case of an accessory liver lobe, located below the left diaphragm, which was misdiagnosed as a metastasis of a known malignant melanoma. The diagnosis ALL was established by a biopsy under guidance of magnetic resonance tomography (MRT). In our opinion, an accessory liver and its appearance should be known, to include this entity in differential diagnosis of perihepatic masses.

We investigated the efficacy of combined FDG-PET/CT imaging for the diagnosis of small-size uveal melanomas and the feasibility of combining separate, high-resolution (HR) FDG-PET with MRI for its improved localization and detection.3 patients with small-size uveal melanomas (0.2-1.5 ml) were imaged on a combined whole-body PET/CT, a HR brain-PET, and a 1.5 T MRI. Static, contrast-enhanced FDG-PET/CT imaging was performed of head and torso with CT contrast enhancement. HR PET imaging was performed in dynamic mode 0-180 min post-injection of FDG. MRI imaging was performed using a high-resolution small-loop-coil placed over the eye in question with T2-3D-TSE and T1-3D-SE with 18 ml Gd-contrast. Patients had their eyes shaded during the scans. Lesion visibility on high-resolution FDG-PET images was graded for confidence: 1: none, 2: suggestive, 3: clear. Mean tumour activity was calculated for summed image frames that resulted in confidence grades 2 and 3. Whole-body FDG-PET/CT images were reviewed for lesions. PET-MRI and PET/CT-MRI images of the head were co-registered for potentially improved lesion delineation.Whole-body FDG-PET/CT images of 3/3 patients were positive for uveal melanomas and negative for disseminated disease. HR FDG-PET was positive already in the early time frames. One patient exhibited rising tumour activity with increasing uptake time on FDG-PET. MRI images of the eye were co-registered successfully to FDG-PET/CT using a manual alignment approach.Small-size uveal melanomas can be detected with whole-body FDG-PET/CT. This feasibility study suggests the exploration of HR FDG-PET in order to provide additional diagnostic information on patients with uveal melanomas. First results support extended uptake times and high-sensitivity PET for improved tumour visibility. MRI/PET co-registration is feasible and provides correlated functional and anatomical information that may support alternative therapy regimens.

In this chapter we present the factors for the success of ERP implementation projects. In the first section, we present the outcome of three surveys on the process and success factors for ERP projects. The first survey was undertaken in 2003 in Germany, the second in 2004 in the United States, and the third in 2006 in Turkey. The results are discussed in light of Hofstede’s model of cultural factors. In the second section we evaluate common ERP lifecycle models. In spite of the great variety of potential advantages, it is also necessary to illuminate the real effects of standard ERP software in practice. Recent studies have revealed that 81% of German companies interviewed using SAP do not fully exploit the software’s ability to optimize business processes, though 61% stated that SAP offers very good process optimization opportunities (Ploenzke, 2000). Therefore we evaluated popular lifecycle models with respect to their suitability to implement standard software in a process-driven way (Kuehl & Knoell, 2002). In the third section we present a semi-process-oriented approach lifecycle model for the implementation and release changeover of ERP systems. This lifecycle model was developed from the authors’ experience in practice, and its practical relevance was evaluated in real-world projects. This approach is also assessed in light of the criteria presented in the second section.

Das primare Tubenkarzinom ist eine Raritat mit schlechter Prognose. Fernmetastasen sind selten. Bei einer erkrankten Patientin fiel unter systemischer Chemotherapie eine intrakardiale, flottierende Raumforderung auf. Die Unterscheidung zwischen Metastase des Tubenkarzinoms und Thrombus wurde mittels eines MRT des Herzens gefuhrt. Es handelte sich um einen residuellen Thrombus welcher sich unter Antikoagulation und Chemotherapie zuruckbildete. Der Fall zeigt, dass bildgebende Verfahren wie das CT und das kontrastmittel-gestutzte MRT der Herzregion eingesetzt werden konnen, um zwischen Thrombus und Metastase zu differenzieren. Schlusselworter: Tubenkarzinom – MRT – CT – intrakardiale Metastase – Thrombus

The REBUS experiment is a valuable benchmark for the validation of Monte Carlo criticality codes within the context of burn-up credit. It investigates the difference in reactivity worth of unirradiated fuel rods and of fuel rods irradiated in a PWR. This paper presents results of criticality calculations for this experiment with the Monte Carlo codes MCNP and SCALE/KENO. Furthermore, calculated results for the 3D core characteristics (fission rate and flux distribution) are compared with the measured values. The application of burn-up credit (BUC) to criticality safety analysis for spent nuclear fuel (SNF) configurations requires the implementation of both estimation of the SNF isotopic composition with the aid of depletion calculation tools and estimation of the SNF reactivity with the aid of criticality calculation tools. While depletion calculation tools have been developed and validated over many years, the calculation tools to predict the SNF reactivity outside the core in storage, transport or disposal conditions are not validated as thoroughly. Since out-of-core SNF operations are usually made without any reactivity monitoring devices, more reliance is placed on the accuracy of the calculated neutron multiplication factor. For these reasons, there is a strong requirement for validation of BUC criticality safety applications.

Sufficient safety margins are essential for preventing local tumor recurrence after radiofrequency ablation RFA of malignant liver tumors. The aim was to determine the initial tumor volume, ablation necrosis volume, and the necrosis-tumor quotient in order to compare these parameters with the rate of local control during follow-up.35 patients with 53 tumor nodules (29 colorectal metastases and 24 HCC nodules) were enrolled. RFA procedures were performed under CT guidance with intravenous conscious sedation. Tumor volumes were measured based on CT data sets and the necrosis volume was assessed using the sum-of-area method. A volumetric necrosis/tumor quotient (NTQ) was calculated for all lesions. Follow-up examinations were performed after 3, 6, and 12 months and then on a yearly basis to identify local recurrent tumors.The CRC metastases and HCC nodules had a median tumor volume of 8.3 ml and 7.4 ml, respectively. The mean ablation volumes were 37.6 ml and 29.5 ml, respectively. This resulted in a median NTQ of 3.9 for metastases and 3.4 for HCC. The follow-up (mean time 18 months) revealed local tumor recurrence in 16 of 29 (55 %) metastases and 10 of 24 (42 %) HCC nodules. In lesions with local recurrence, the initial tumor volume was significantly greater and the NTQ was significantly smaller. A threshold value of 3.4 for NTQ has the highest predictive value for local tumor recurrence.The volumetric necrosis/tumor quotient NTQ makes it possible to predict the local outcome and can be used for the planning of additional therapy.