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Featured researches published by A Bücker.


Langenbeck's Archives of Surgery | 2015

Transarterial chemoembolization (TACE) for colorectal liver metastases—current status and critical review

Alexander Massmann; Thomas Rodt; Steffen Marquardt; Roland Seidel; Katrina Thomas; Frank Wacker; Götz M. Richter; Hans U. Kauczor; A Bücker; Philippe L. Pereira; Christof M. Sommer

BackgroundTransarterial liver-directed therapies are currently not recommended as a standard treatment for colorectal liver metastases. Transarterial chemoembolization (TACE), however, is increasingly used for patients with liver-dominant colorectal metastases after failure of surgery or systemic chemotherapy. The limited available data potentially reveals TACE as a valuable option for pre- and post-operative downsizing, minimizing time-to-surgery, and prolongation of overall survival after surgery in patients with colorectal liver only metastases.PurposeIn this overview, the current status of TACE for the treatment of liver-dominant colorectal liver metastases is presented. Critical comments on its rationale, technical success, complications, toxicity, and side effects as well as oncologic outcomes are discussed. The role of TACE as a valuable adjunct to surgery is addressed regarding pre- and post-operative downsizing, conversion to resectability as well as improvement of the recurrence rate after potentially curative liver resection. Additionally, the concept of TACE for liver-dominant metastatic disease with a focus on new embolization technologies is outlined.ConclusionsThere is encouraging data with regard to technical success, safety, and oncologic efficacy of TACE for colorectal liver metastases. The majority of studies are non-randomized single-center series mostly after failure of systemic therapies in the 2nd line and beyond. Emerging techniques including embolization with calibrated microspheres, with or without additional cytotoxic drugs, degradable starch microspheres, and technical innovations, e.g., cone-beam computed tomography (CT) allow a new highly standardized TACE procedure. The real efficacy of TACE for colorectal liver metastases in a neoadjuvant, adjuvant, and palliative setting has now to be evaluated in prospective randomized controlled trials.


European Journal of Radiology | 2017

Transarterial embolization (TAE) as add-on to percutaneous radiofrequency ablation (RFA) for the treatment of renal tumors: Review of the literature, overview of state-of-the-art embolization materials and further perspective of advanced image-guided tumor ablation

Cm Sommer; L. Pallwein-Prettner; D.F. Vollherbst; Roland Seidel; C. Rieder; B Radeleff; Hu Kauczor; Frank Wacker; Götz M. Richter; A Bücker; Thomas Rodt; Alexander Massmann; Philippe L. Pereira

Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image-guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of T1a tumors in difficult locations and T1b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of bland RFA. Clinical implementation is extremely important for performing image-guided TA as a highly standardized effective procedure even in the most challenging cases of localized renal tumors.


Radiologe | 2007

Magnetresonanztomographie und -angiographie der Aorta

Günther Schneider; Alexander Massmann; Katrin Altmeyer; Marcus Katoh; A Bücker

When a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR -imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a noninvasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.ZusammenfassungBei der Bildgebung von Erkrankungen der Aorta können heute je nach Krankheitsbild und Dringlichkeit unterschiedliche Verfahren zur Anwendung kommen. Neuere Verfahren stellen die konventionelle MR-Tomographie und speziell die kontrastverstärkte MR-Angiographie dar, die nichtinvasiv die Kombination von Anatomie, Akquisition physiologischer Parameter und 3D-Angiographie kombiniert. In diesem Artikel werden sowohl technische als auch klinische Aspekte bei der Anwendung der MR-Tomographie bei Erkrankungen der Aorta diskutiert. Inhaltlich werden sowohl angeborene Fehlbildungen, erworbene Erkrankungen wie auch entzündliche Veränderungen der Aorta dargestellt.AbstractWhen a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR –imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a nonivasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.


Rofo-fortschritte Auf Dem Gebiet Der Rontgenstrahlen Und Der Bildgebenden Verfahren | 2015

Evaluation of a Gadolinium-Based Nanoparticle (AGuIX) for Contrast-Enhanced MRI of the Liver in a Rat Model of Hepatic Colorectal Cancer Metastases at 9.4 Tesla

Peter Fries; D Morr; Andreas Müller; François Lux; O. Tillement; A Massmann; R Seidel; T. Schäfer; Michael D. Menger; Günther Schneider; A Bücker

PURPOSE The aim of this study was to compare a Gd-based nanoparticle (AGuIX) with a standard extracellular Gd-based contrast agent (Gd-DOTA) for MRI at 9.4 T in rats with hepatic colorectal cancer metastases. MATERIALS AND METHODS 12 rats with hepatic metastases were subjected to MRI using a 9.4 T animal scanner. T1w self-gated FLASH sequences (TR/TE = 45/2.5 ms, alpha = 45°, TA = 1: 23 min, FOV = 5.12 × 5.12 cm(2), matrix = 256 × 256) were acquired before and at 10 time points after contrast injection. Each animal received 0.1 mmol/kg BW Gd-DOTA i.v. 2 days later AGuIX was applied at 0.01 mmol/kg BW (representing equal Gd doses). The SNR of normal liver (SNRliver), hyper- and hypoenhancing parts of tumors (SNRtumor, hyperenh/SNRtumor, hypoenhanc), erector spinae muscle (SNRmuscle), CNR and lesion enhancement (LE) were calculated based on ROI measurements. RESULTS Mean SNRliver (Gd-DOTA: 14.6 +/- 0.7; AGuIX: 28.2+/- 2.6, p < 0.001), SNRtumor, hyperenhanc (Gd-DOTA: 18.6 +/- 1.2; AGuIX: 29.6 +/- 2.8, p < 0.001), SNRtumor, hypoenhanc (Gd-DOTA: 12.0 +/- 0.7; AGuIX: 15.4 +/- 0.7, p < 0.001), SNRmuscle (Gd-DOTA: 12.3 +/- 0.3; AGuIX: 14.0 +/- 0.7, p < 0.001), mean CNR (Gd-DOTA: -2.5 +/- 0.2; AGuIX: -7.5 +/- 1.0, p < 0.001) and LE (Gd-DOTA: 3.8 +/- 0.7; AGuIX: 14.9 +/- 2.8, p = 0.001) were significantly higher using AGuIX. Regardless of the larger molecular size, AGuIX demonstrates an early peak enhancement followed by a continuous washout. CONCLUSION AGuIX provides better enhancement at 9.4 T compared to Gd-DOTA for equal doses of applied Gd. This is based on the molecule structure and the subsequent increased interaction with protons leading to a higher relaxivity. AGuIX potentially ameliorates the conspicuity of focal liver lesions and may improve the sensitivity in diagnostic imaging of malignant hepatic tumors. KEY POINTS AGuIX provides superior enhancement as compared to the extracellular compound Gd-DOTA at 9.4 T. AGuIX may improve the detection and diagnostic sensitivity of malignant focal liver lesions. The small size of AGuIX allows for fast renal clearance and prevents undesirable accumulation in the body.


Rofo-fortschritte Auf Dem Gebiet Der Rontgenstrahlen Und Der Bildgebenden Verfahren | 2011

Subintimal Revascularization of Chronic Iliac Artery Occlusions using a Reentry-Catheter

Peter Minko; Marcus Katoh; A Opitz; S Jäger; A Bücker

PURPOSE To demonstrate the value of a Reentry-Catheter for true lumen access after subintimal revascularization of chronic iliac artery occlusions. MATERIALS AND METHODS Subintimal revascularization was performed in 5 patients (mean age: 67 ± 12 years; female: 3, male: 2) with total iliac artery occlusion (TASC B to D), but without gaining access to the true lumen distal to the occlusion. Subsequently, a Reentry-Catheter was used to establish reentry and a new subintimal tract. Patients were followed up after 6, 12 and 24 months for clinical re-evaluation to determine the Rutherford score and the ankle brachial index (ABI). In addition, duplex ultrasound was performed to evaluate vessel patency. RESULTS The primary technical success rate was 100 %. In all cases angioplasty was followed by stent placement to establish the subintimal tract. The mean Rutherford score decreased from 3.6 ± 0.9 to 0.33 ± 0.57 after 24 months, while the ABI increased from 0.67 ± 0.06 to 1.2 ± 0. Vessel patency was observed in all patients available for follow-up examinations. CONCLUSION The Reentry-Catheter reliably allowed access to the true lumen after subintimal revascularization of occluded iliac arteries. Results in this small patient cohort showed a significant reduction in the Rutherford score, increase in the ABI, and a good patency rate after two years.


Clinical Research in Cardiology | 2009

MRI and contrast enhanced MR angiography in a patient with right aortic arch and aberrant left subclavian artery

Peter Fries; Günther Schneider; Angelika Lindinger; Hashim Abdul-Khaliq; Hans-Joachim Schäfers; A Bücker

IntroductionCongenital malformations of the aortic arch are animportant group of pediatric pathologies. Depending on thetype of the vascular anomaly, patients may be completelyasymptomatic not requiring any therapy or may manifestwith hazardous or even life threatening situations such asrecurrent pneumonia, respiratory distress or apnea [1]. Dueto the complexity of pathologic anatomy, the clinicalsymptoms and the resulting therapeutic consequences thesemalformations require detailed diagnostic imaging.MRI is nowadays considered the imaging modality ofchoice for the work-up of vascular malformations in thepediatric age group. The application of Cine SSFP (steadystate free precession) sequences and flow sensitive phase-contrast sequences allow for depiction of vascular struc-tures and qualitative as well as quantitative assessment ofblood flow. In addition, contrast enhanced magnetic reso-nance angiography (CE-MRA) provides high-resolutionthree-dimensional (3D) datasets providing excellent imagesof even small vascular structures based on maximumintensity projection (MIP), volume rendering technique(VRT), and multiplanar reconstructions (MPR). Recentstudies have shown that CE-MRA in the pediatric agegroup may clarify uncertain diagnoses in one-third of thepatients and reveal additional unsuspected pathologicstructures in another third of cases [2, 3]. Furthermore, CE-MRA has been shown to be superior to echocardiographyfor evaluation of the pulmonary vasculature in pediatricpatients [3], [4].The value of unenhanced MRI and CE-MRA in imagingof vascular anomalies in pediatric subjects is highlighted inthis case of a congenital malformation of the aortic archwith aberrant left subclavian artery.CaseA 14-year old male patient presented with dysphagia,globus, and temporary malaise without vomiting. Physicalexamination of the patient was normal and there were nosigns of dyspnea, dizziness, or chest pain. ECG and bloodanalysis did not reveal any abnormality. A frontal viewX-ray examination of the chest demonstrated a right-sidedaortic arch (Fig. 1). Barium esophagography, performedfor further evaluation of dysphagia, revealed a right-sidedand posterior compression of the proximal esophagus at thelevel of the aortic arch (Fig. 2). The echocardiographicexamination showed regular intracardiac structures andfunction; there was a right aortic arch with origin of the leftand right carotid artery as the first two supra-aortic vessels.Based on these findings the patient was referred for MRIexamination.MRI was performed on a 1.5 T Siemens MagnetomSonata system (Siemens Medical Systems, Erlangen,Germany) using a phased-array body coil. The unenhancedMRI sequences utilized comprised T2w HASTE sequenceand retrospectively ECG-gated Cine SSFP sequences. Con-trast enhanced magnetic resonance angiography (CE-MRA)


Radiologe | 2007

MR imaging and MR angiography of the aorta

Günther Schneider; Alexander Massmann; Katrin Altmeyer; Marcus Katoh; A Bücker

When a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR -imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a noninvasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.ZusammenfassungBei der Bildgebung von Erkrankungen der Aorta können heute je nach Krankheitsbild und Dringlichkeit unterschiedliche Verfahren zur Anwendung kommen. Neuere Verfahren stellen die konventionelle MR-Tomographie und speziell die kontrastverstärkte MR-Angiographie dar, die nichtinvasiv die Kombination von Anatomie, Akquisition physiologischer Parameter und 3D-Angiographie kombiniert. In diesem Artikel werden sowohl technische als auch klinische Aspekte bei der Anwendung der MR-Tomographie bei Erkrankungen der Aorta diskutiert. Inhaltlich werden sowohl angeborene Fehlbildungen, erworbene Erkrankungen wie auch entzündliche Veränderungen der Aorta dargestellt.AbstractWhen a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR –imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a nonivasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.


ChemMedChem | 2016

Small BODIPY Probes for Combined Dual 19F MRI and Fluorescence Imaging

Anh Minh Huynh; Andreas Müller; Sonja M. Kessler; Sarah Henrikus; Caroline Hoffmann; Alexandra K. Kiemer; A Bücker; Gregor Jung

The combination of the two complementary imaging modalities 19F magnetic resonance imaging (MRI) and fluorescence imaging (FLI) possesses high potential for biological and medical applications. Herein we report the first design, synthesis, dual detection validation, and cytotoxic testing of four promising BODIPY dyes for dual 19F MRI–fluorescence detection. Using straightforward Steglich reactions, small fluorinated alcohols were easily covalently tethered to a BODIPY dye in high yields, leaving its fluorescence properties unaffected. The synthesized compounds were analyzed with various techniques to demonstrate their potential utility in dual imaging. As expected, the chemically and magnetically equivalent trifluoromethyl groups of the agents exhibited a single NMR signal. The determined longitudinal relaxation times T1 and the transverse relaxation times T2, both in the lower second range, enabled the imaging of four compounds in vitro. The most auspicious dual 19F MRI–fluorescence agent was also successfully imaged in a mouse post‐mortem within a 9.4 T small‐animal tomograph. Toxicological assays with human cells (primary HUVEC and HepG2 cell line) also indicated the possibility for animal testing.


Radiologe | 2007

Magnetresonanztomographie und -angiographie der Aorta@@@MR imaging and MR angiography of the aorta

Günther Schneider; Alexander Massmann; Katrin Altmeyer; Marcus Katoh; A Bücker

When a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR -imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a noninvasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.ZusammenfassungBei der Bildgebung von Erkrankungen der Aorta können heute je nach Krankheitsbild und Dringlichkeit unterschiedliche Verfahren zur Anwendung kommen. Neuere Verfahren stellen die konventionelle MR-Tomographie und speziell die kontrastverstärkte MR-Angiographie dar, die nichtinvasiv die Kombination von Anatomie, Akquisition physiologischer Parameter und 3D-Angiographie kombiniert. In diesem Artikel werden sowohl technische als auch klinische Aspekte bei der Anwendung der MR-Tomographie bei Erkrankungen der Aorta diskutiert. Inhaltlich werden sowohl angeborene Fehlbildungen, erworbene Erkrankungen wie auch entzündliche Veränderungen der Aorta dargestellt.AbstractWhen a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR –imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a nonivasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions.


Geburtshilfe Und Frauenheilkunde | 2018

Interdisciplinary Screening, Diagnosis, Therapy and Follow-up of Breast Cancer. Guideline of the DGGG and the DKG (S3-Level, AWMF Registry Number 032/045OL, December 2017) – Part 1 with Recommendations for the Screening, Diagnosis and Therapy of Breast Cancer

Achim Wöckel; Jasmin Festl; Tanja Stüber; Katharina Brust; Stephanie Stangl; Peter Heuschmann; Ute-Susann Albert; Wilfried Budach; Markus Follmann; Wolfgang Janni; Ina Kopp; Rolf Kreienberg; Thorsten Kühn; Thomas Langer; Monika Nothacker; Anton Scharl; Ingrid Schreer; Hartmut Link; Jutta Engel; Tanja Fehm; Joachim Weis; Anja Welt; Anke Steckelberg; Petra Feyer; K. König; Andrea Hahne; Hans Kreipe; Wolfram Knoefel; Michael Denkinger; Sara Y. Brucker

Purpose The aim of this official guideline coordinated and published by the German Society for Gynecology and Obstetrics (DGGG) and the German Cancer Society (DKG) was to optimize the screening, diagnosis, therapy and follow-up care of breast cancer. Methods The process of updating the S3 guideline dating from 2012 was based on the adaptation of identified source guidelines which were combined with reviews of evidence compiled using PICO (Patients/Interventions/Control/Outcome) questions and the results of a systematic search of literature databases and the selection and evaluation of the identified literature. The interdisciplinary working groups took the identified materials as their starting point to develop recommendations and statements which were modified and graded in a structured consensus procedure. Recommendations Part 1 of this short version of the guideline presents recommendations for the screening, diagnosis and follow-up care of breast cancer. The importance of mammography for screening is confirmed in this updated version of the guideline and forms the basis for all screening. In addition to the conventional methods used to diagnose breast cancer, computed tomography (CT) is recommended for staging in women with a higher risk of recurrence. The follow-up concept includes suggested intervals between physical, ultrasound and mammography examinations, additional high-tech diagnostic procedures, and the determination of tumor markers for the evaluation of metastatic disease.

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D Morr

Saarland University

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