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Dive into the research topics where Werner Kenn is active.

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Featured researches published by Werner Kenn.


The New England Journal of Medicine | 2012

Combination chemotherapy in advanced adrenocortical carcinoma

Martin Fassnacht; Massimo Terzolo; Bruno Allolio; Eric Baudin; Harm R. Haak; Alfredo Berruti; Staffan Welin; Carmen Schade-Brittinger; André Lacroix; Barbara Jarzab; Halfdan Sorbye; David J. Torpy; Vinzenz Stepan; David E. Schteingart; Wiebke Arlt; Matthias Kroiss; Sophie Leboulleux; Paola Sperone; Anders Sundin; Ilse Hermsen; Stefanie Hahner; Holger S. Willenberg; Antoine Tabarin; Marcus Quinkler; Martin Schlumberger; Franco Mantero; Dirk Weismann; Felix Beuschlein; Hans Gelderblom; Hanneke Wilmink

BACKGROUND Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment. METHODS We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival. RESULTS For first-line therapy, patients in the EDP-mitotane group had a significantly higher response rate than those in the streptozocin-mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP-mitotane group and 2.2 months in the streptozocin-mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments. CONCLUSIONS Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival. (Funded by the Swedish Research Council and others; FIRM-ACT ClinicalTrials.gov number, NCT00094497.).


European Radiology | 2000

Age- and gender-specific differences in left and right ventricular cardiac function and mass determined by cine magnetic resonance imaging.

J. Sandstede; C. Lipke; Meinrad Beer; S. Hofmann; Thomas Pabst; Werner Kenn; S. Neubauer; Dietbert Hahn

Abstract. We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 ± 7), women aged under 45 (27 ± 6), men aged over 45 (59 ± 8), and women aged over 45 (57 ± 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 ± 18 and 110 ± 16 g; LV EDV, 118 ± 27 and 96 ± 21 ml; LV ESV, 40 ± 13 and 29 ± 9 ml; RV mass, 52 ± 10 and 39 ± 5 g; RV EDV, 131 ± 28 and 100 ± 23 ml; RV ESV, 53 ± 17 and 33 ± 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4 % and 5.9 % for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values.


Cancer | 2009

Radiotherapy in adrenocortical carcinoma

Buelent Polat; Martin Fassnacht; Leo Pfreundner; Matthias Guckenberger; Klaus Bratengeier; Sarah Johanssen; Werner Kenn; Stefanie Hahner; Bruno Allolio; Michael Flentje

Adrenocortical carcinoma (ACC) is a rare malignancy, and patients with ACC have a poor prognosis. Even after radical surgery, up to 85% of patients develop recurrent disease. Systemic treatment options still have limited efficacy. Because the role of radiotherapy is not defined well and because ACC often is considered radioresistant, the authors reviewed the available data on radiotherapy for ACC. Original articles and reviews were identified using a PubMed search strategy that included the period up to July 2008. Ten articles were identified that covered radiotherapy in a total of 129 patients with ACC (64 patients received postoperative irradiation, and 65 patients received palliative therapy for advanced disease). In addition, 26 patients were identified in the German ACC Registry who received palliative radiotherapy. Furthermore, patterns of failure after adjuvant radiotherapy were investigated, and the authors provided recommendations for patient selection, treatment planning, and treatment protocols. In an adjuvant setting, postoperative radiotherapy was able to prevent local recurrence in the majority of patients. In those with advanced disease, a response to radiotherapy was observed in 57% of patients who received palliative radiotherapy. Therefore, the authors concluded that radiotherapy may play an important role in the care of patients with ACC. Until better evidence is available, the authors recommended the following approach: Adjuvant radiotherapy to the tumor bed should be considered in patients at high risk for local recurrence (eg, incomplete/R1 resection); a total dose of >40 grays (Gy) with single fractions of 1.8 Gy to 2 Gy should be administered (including a boost volume to reach from 50 Gy to 60 Gy in individual patients); and radiotherapy in a palliative setting may be used for symptomatic metastases to bone, brain, or vena cava obstruction. With state‐of‐the‐art technology, acute and long‐term toxicities mostly were mild to moderate. However, the authors concluded that prospective investigations would be required to fully define the therapeutic potential of this important treatment option. Cancer 2009.


Journal of Endocrinological Investigation | 2004

Adrenal tumors: How to establish malignancy?

Martin Fassnacht; Werner Kenn; Bruno Allolio

Discerning malignancy in adrenal tumors largely influences disease management and is, therefore, of utmost importance to both patient and physician. Clinical presentation (e.g. virilization) and baseline hormonal evaluation (e.g. high serum DHEAS) are occasionally of great value but usually provide only limited help in predicting malignancy. The probability of malignancy is clearly related to tumor size, as almost all lesions <3 cm are benign whereas a diameter of >6 cm indicates a high risk of malignancy. Computed tomography (CT) and magnetic resonance imaging (MRI) both contribute significantly to the characterization of adrenal masses. If the attenuation of a homogeneous mass with smooth border is 10 Hounsfield units or less in unenhanced CT the diagnosis of a lipid rich adenoma is established. Similarly, enhancement washout of more than 50% in CT at 10–15 min suggests a benign lesion. In MRI both rapid contrast enhancement after gadolinium followed by rapid washout and signal intensity loss using opposed-phase image in chemical shift analysis also indicate the presence of an adenoma. In contrast, adrenal carcinomas — but also pheochromocytomas — typically present as inhomogeneous lesion with intermediate-to-high intensity on T2 images in MRI. Margins and enhancement after contrast media in CT are irregular in adrenal carcinoma. Other imaging techniques either offer little additional information (NP-59 scintigraphy) or have not yet been fully established (positron emission tomography). Fine needle aspiration/cut biopsy is at present restricted to patients with a known extra-adrenal malignancy and suspected adrenal metastasis as the only evidence of disseminated disease. Adrenal tumors classified as benign undergo follow-up imaging to assess tumor growth. If an increase in diameter of >1 cm is seen, surgical removal is recommended. Even after tumor removal the diagnosis of dignity may remain difficult. Diagnostic scores together with new immunohistological markers are the methods of choice to assess malignancy. In conclusion, an interdisciplinary approach with a structured use of available diagnostic tools is needed to classify adrenal tumors correctly.


European Radiology | 2000

Technical advances in ultrasound and MR imaging of carpal tunnel syndrome

Marc Keberle; Manfred Jenett; Werner Kenn; K. Reiners; M. Peter; Rainer Haerten; Dietbert Hahn

Abstract. The aim of this study was to compare the latest ultrasound-array technology to a conventional “high-resolution” transducer, modified MRI technique, and nerve conduction studies (NCS), in the diagnosis of carpal tunnel syndrome (CTS). In 19 normal wrists and 15 wrists with CTS, US with two different transducers was performed: a conventional linear-array transducer (LA) and a newly developed Multi-D linear-array transducer (MDA) were used. The US images were evaluated determining the swelling and the flattening ratios of the median nerve and correlated to respective findings in MRI (1.5 T) and to NCS. The NCS confirmed CTS in all 15 wrists. Measures of median nerve compression (swelling and flattening ratios) were significantly different in patients with CTS and controls (p < 0.01) with both types of US transducers and MRI. The MDA yielded higher correlation to MRI than the LA. Using critical values of 1.3 for the swelling and 3.4 for the flattening ratio, MRI, and US with the MDA yielded a sensitivity of 100 % each. Modern imaging modalities allow for an exact diagnosis of CTS even in cases with only slight median nerve pathology.


Magnetic Resonance Imaging | 1999

Detection of myocardial viability by low-dose dobutamine Cine MR imaging.

Joern Sandstede; Gerald Bertsch; Meinrad Beer; Werner Kenn; Edgar Werner; Thomas Pabst; Claudia Lipke; Susanne Kretschmer; Stefan Neubauer; Dietbert Hahn

The purpose of this work was to test the diagnostic value of dobutamine stress magnetic resonance imaging (MRI) for predicting recovery of regional myocardial contractility after revascularization. Cardiac wall motion abnormalities are due to either non-viable and/or scarred, or viable, but hibernating, myocardial tissue. Dobutamine stress leads to increased systolic wall thickening only in viable myocardium. Twenty-five patients with akinetic or dyskinetic myocardial regions were examined with a Cine FLASH-2D sequence at rest and during dobutamine stress (10 microg/kg/min). Patients were re-examined at rest 3, and in case of persisting wall motion defects, 6 months after revascularization. Criterion of viability was increasing end-systolic wall thickening during stress and/or at follow-up. Akinetic regions related either to the LAD (n = 19) or to the RCA (n = 6) were judged viable if > or = 50% of the affected segments improved. MR studies were completed in all subjects without arrhythmia or need for early terminations due to symptoms. Sensitivity, specificity, and positive predictive value for the prediction of myocardial viability were 61%, 90%, and 87% for the segment-related analysis, and 76%, 100%, and 100% for the patient-related analysis based on coronary artery distribution, respectively. Dobutamine stress MRI allows to predict global functional recovery of akinetic myocardial regions after revascularization with a high positive predictive value and high specificity.


Journal of Bone and Mineral Research | 2004

Gorham-Stout Disease—Stabilization During Bisphosphonate Treatment†

Fabian Hammer; Werner Kenn; Ulrich Wesselmann; Lorenz C. Hofbauer; G. Delling; Bruno Allolio; Wiebke Arlt

A 45‐year‐old woman presented with recent onset of left‐sided chest pain. On clinical examination, these symptoms seemed to be strictly localized to a region that was marked by a long‐standing cutaneous erythematous lesion. Laboratory results showed no gross abnormalities. Radiological imaging including conventional X‐ray, MRI scans, and 3D CT reconstruction of the rib cage revealed circumscript destruction of the left lateral ribs 9–11. Histological analysis of a rib biopsy showed angiomatous hypervascularization and intracortical fibrosis. In keeping with these findings, the patients condition was diagnosed as Gorham‐Stout disease, a rare condition with localized, often unilateral, bone destruction. Monotherapy with bisphosphonates (pamidronate 30 mg IV every 3 months) was initiated, leading to rapid disappearance of local pain. Follow‐up over 24 months documented a stable clinical and radiological picture without evidence of progressive bone destruction.


European Radiology | 1999

Spiral CT angiography of renal arteries: comparison with angiography

Guenther Wittenberg; Werner Kenn; Alexander Tschammler; J. Sandstede; Dietbert Hahn

Abstract. A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100–150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause.


European Radiology | 2002

Current concepts in imaging of laryngeal and hypopharyngeal cancer

Marc Keberle; Werner Kenn; Dietbert Hahn

Abstract. In adjunct to direct laryngoscopy, CT and/or MRI are needed for an accurate staging of laryngeal and hypopharyngeal carcinomas because both cross-sectional imaging modalities are known to reliably evaluate deep tumor infiltration. Except for the clinical background, this article reviews technical aspects of CT and MRI, the pathologic appearance of laryngeal and hypopharyngeal carcinomas, and therapeutically relevant diagnostic aspects.


Journal of Magnetic Resonance Imaging | 2000

Changes in left and right ventricular cardiac function after valve replacement for aortic stenosis determined by cine MR imaging.

J. Sandstede; Meinrad Beer; S. Hofmann; Claudia Lipke; Kerstin Harre; Thomas Pabst; Werner Kenn; S. Neubauer; Dietbert Hahn

The purpose of this study was to determine the changes in function of both the left and the right ventricles (LV, RV) before and after aortic valve replacement (AVR), compared with age‐matched healthy volunteers using magnetic resonance (MR) imaging. Fourteen patients with aortic stenosis underwent MR imaging (1.5 T) before and 3 (n = 14) and 12 (n = 9) months after surgical valve replacement. An electrocardiographically triggered two‐dimensional cine fast low‐angle shot sequence was used for the evaluation of absolute values and indices related to 1 m 2 body surface area for function, mass, and LV wall thickening. Fourteen age‐matched healthy volunteers served as controls. Before surgery, all patients showed significant abnormalities of LV mass and function, whereas RV mass and function were not different from those of volunteers and remained mostly unchanged. After surgery, normalization of LV ejection fraction, absolute mass, and end‐systolic wall thickness was observed, whereas the LV mass index failed to normalize, and LV volumes remained elevated. Aortic stenosis combined with a significant, but not severe reduction in LV function only affects the LV, whereas the RV remains unaffected at this stage of disease. AVR leads to improved LV function and reduced hypertrophy, but without normalization of LV volumes or the LV mass index within 1 year. J. Magn. Reson. Imaging 2000;12:240–246.

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Thomas Pabst

University of Würzburg

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Meinrad Beer

University of Würzburg

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J. Sandstede

University of Würzburg

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D Hahn

University of Oxford

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S. Neubauer

University of Würzburg

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