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Dive into the research topics where Werner Dolak is active.

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Featured researches published by Werner Dolak.


Haematologica | 2013

A phase II study of lenalidomide in patients with extranodal marginal zone B-cell lymphoma of the mucosa associated lymphoid tissue (MALT lymphoma)

Barbara Kiesewetter; Marlene Troch; Werner Dolak; Leonhard Müllauer; Julius Lukas; Christoph C. Zielinski; Markus Raderer

Mucosa associated lymphoid tissue lymphoma shares certain features with multiple myeloma. In view of this and the activity of lenalidomide in various B-cell lymphomas, we have initiated a phase II study of lenalidomide in patients with mucosa associated lymphoid tissue lymphoma. Patients with histologically verified advanced stages of this lymphoma were included in the study. Treatment consisted of oral lenalidomide 25 mg Days 1–21, with a 7-day break after each cycle. A total of 18 patients were included in the trial: 5 had gastric and 13 had extragastric mucosa associated lymphoid tissue lymphoma, but 2 discontinued therapy during the first course of therapy. In the intent to treat analysis, an overall response rate of 61% was seen (11 of 18; 6 complete and 5 partial remissions). Three patients had stable disease while 2 progressed. Side effects were manageable and included neutropenia (grade III in 3 patients) as the leading hematotoxicity. After a median follow up of 20.3 months, one patient has died from lymphoma while the remaining patients are alive and relapse-free. These data suggest activity of lenalidomide monotherapy in mucosa associated lymphoid tissue lymphoma. The study protocol had been approved by the Ethical Board of the Medical University Vienna (EK-No.: 146/09), and before opening the trial, it had been registered at www.clinicaltrials.gov. (identifier: NCT00923663).


Clinical Cancer Research | 2014

Evaluation of Diffusion-Weighted MRI for Pretherapeutic Assessment and Staging of Lymphoma: Results of a Prospective Study in 140 Patients

Marius E. Mayerhoefer; Georgios Karanikas; Kurt Kletter; Helmut Prosch; Barbara Kiesewetter; Cathrin Skrabs; Edit Porpaczy; Michael Weber; Katja Pinker-Domenig; Dominik Berzaczy; Martha Hoffmann; Christian Sillaber; Ulrich Jaeger; Leonhard Müllauer; Ingrid Simonitsch-Klupp; Werner Dolak; Alexander Gaiger; Philipp Ubl; Julius Lukas; Markus Raderer

Purpose: To determine the value of diffusion-weighted MRI (DWI-MRI) for pretherapeutic imaging of fluorodeoxyglucose (FDG)-avid lymphoma and lymphoma with variable FDG avidity. Experimental Design: Treatment-naïve patients with lymphoma who were referred for whole-body staging were included in this prospective study. Group A included patients with FDG-avid lymphoma (e.g., Hodgkin, diffuse large B-cell, and follicular lymphoma), whereas Group B included patients with lymphoma of variable FDG avidity [e.g., extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)]. All patients underwent DWI-MRI and 18F-FDG- positron emission tomography/computed tomography (PET/CT). Region-based sensitivity and agreement with Ann Arbor staging, relative to the reference standard, were calculated for DWI-MRI, and, in Group B, also 18F-FDG-PET/CT and contrast-enhanced (CE-) CT. Results: In Group A (100 patients), DWI-MRI had a region-based sensitivity of 97%, and with regard to staging, agreed with the reference standard in 94 of 100 patients (κ, 0.92). In Group B (40 patients; 38 MALT lymphomas and 2 small lymphocytic lymphomas/chronic lymphocytic leukemias), DWI-MRI, 18F-FDG-PET/CT, and CE-CT had region-based sensitivities of 94.4%, 60.9%, and 70.7%, respectively. With regard to staging in Group B, DWI-MRI, 18F-FDG-PET/CT, and CE-CT agreed with the reference standard in 37 of 40, 26 of 40, and 24 of 40 patients, with κ values of 0.89, 0.52, and 0.43, respectively. Conclusions: In patients with FDG-avid lymphoma, DWI-MRI seems to be only slightly inferior to 18F-FDG-PET/CT with regard to pretherapeutic regional assessment and staging. In patients with lymphoma subtypes that show a variable FDG avidity (e.g., MALT lymphoma), DWI-MRI seems to be superior to both 18F-FDG-PET/CT and CE-CT. Clin Cancer Res; 20(11); 2984–93. ©2014 AACR.


Clinical Cancer Research | 2015

Evaluation of Diffusion-weighted Magnetic Resonance Imaging for Follow-Up and Treatment Response Assessment of Lymphoma: Results of an 18F-FDG-PET/CT-controlled Prospective Study in 64 Patients

Marius E. Mayerhoefer; Georgios Karanikas; Kurt Kletter; Helmut Prosch; Barbara Kiesewetter; Cathrin Skrabs; Edit Porpaczy; Michael Weber; Thomas Knogler; Christian Sillaber; Ulrich Jaeger; Ingrid Simonitsch-Klupp; Philipp Ubl; Leonhard Müllauer; Werner Dolak; Julius Lukas; Markus Raderer

Purpose: To determine the value of diffusion-weighted MRI (DWI-MRI) for treatment response assessment in 2-[18F]fluoro-2-deoxy-D-glucose (FDG)–avid lymphoma. Experimental Design: Patients with FDG-avid Hodgkin (HL) or non-Hodgkin lymphoma (NHL) at pretherapeutic 18F-FDG-PET/CT, who had also undergone pretherapeutic whole-body DWI-MRI, were included in this prospective study. Depending on the histologic lymphoma subtype, patients received different systemic treatment regimens, and follow-up DWI-MRI and 18F-FDG-PET/CT were performed at one or more time points, depending on the clinical course. For each follow-up DWI-MRI, region-based rates of agreement, and rates of agreement in terms of treatment response (complete remission, partial remission, stable disease, or progressive disease), relative to the corresponding 18F-FDG-PET/CT, were calculated. Results: Sixty-four patients were included: 10 with HL, 22 with aggressive NHL, and 32 with indolent NHL. The overall region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.4%. For the 51 interim examinations (performed after 1–3 therapy cycles), region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.2%, and for the 48 end-of-treatment examinations, agreement was 99.8%. No significant differences, in terms of region-based agreement between DWI-MRI and 18F-FDG-PET/CT, were observed between the three lymphoma groups (HL, aggressive NHL, indolent NHL; P = 0.25), or between interim and end-of-treatment examinations (P = 0.21). With regard to treatment response assessment, DWI-MRI agreed with 18F-FDG-PET/CT in 99 of 102 follow-up examinations (97.1%), with a κ value of 0.94 (P < 0.0001). Conclusions: In patients with FDG-avid lymphoma, DWI-MRI may be a feasible alternative to 18F-FDG-PET/CT for follow-up and treatment response assessment. Clin Cancer Res; 21(11); 2506–13. ©2015 AACR.


Endoscopy | 2012

A randomized head-to-head study of small-bowel imaging comparing MiroCam and EndoCapsule.

Werner Dolak; Stefanie Kulnigg-Dabsch; R. Evstatiev; Christoph Gasche; Michael Trauner; Andreas Püspök

BACKGROUND AND STUDY AIMS The MiroCam is a new video capsule device offering a higher frame rate and a longer battery life-expectancy. We aimed to quantify its clinical impact and performed a randomized head-to-head comparison with the EndoCapsule device with respect to the rate of complete small-bowel examinations, diagnostic yield in the small bowel, and capsule transit time. PATIENTS AND METHODS Patients referred for video capsule endoscopy because of obscure gastrointestinal bleeding, chronic diarrhea, and anemia of unknown origin were randomly assigned to swallow either the MiroCam first, followed by the EndoCapsule 2 hours later, or vice versa. All videos were analyzed by two independent investigators. RESULTS A total of 50 patients (median age 61, range 21-84) were included. Complete small-bowel examination was achieved in 48/50 patients using the MiroCam and 45/50 using the EndoCapsule (96% vs. 90%, odds ratio [OR] 2.67, 95% confidence interval [CI] 0.49-14.45; P=0.38). There was diagnostic yield in the small bowel for 25/50 patients using the MiroCam and 24/50 using the EndoCapsule (50% vs. 48%, OR 1.08, 95%CI 0.49-2.37; P>0.99). However, the findings were concordant in 68% only (kappa = 0.50). The combined diagnostic yield was 58%. Even solitary findings had a relevant clinical impact during a 6-month follow-up. CONCLUSION In this direct comparison the MiroCam and EndoCapsule devices were not statistically different with regard to their rates of complete small-bowel examinations or diagnostic yield. Their moderate concordance, mainly caused by missed pathological findings, which affected both devices, needs consideration in clinical practice.


Investigative Radiology | 2016

18F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance in Lymphoma: Comparison With 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and With the Addition of Magnetic Resonance Diffusion-Weighted Imaging.

Chiara Giraudo; Markus Raderer; Georgios Karanikas; Michael Weber; Barbara Kiesewetter; Werner Dolak; Ingrid Simonitsch-Klupp; Marius E. Mayerhoefer

ObjectivesThe aim of this study was to compare 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) (with and without diffusion-weighted imaging [DWI]) to 18F-FDG PET/computed tomography (CT), with regard to the assessment of nodal and extranodal involvement, in patients with Hodgkin lymphoma and non-Hodgkin lymphoma, without restriction to FDG-avid subytpes. Materials and MethodsPatients with histologically proven lymphoma were enrolled in this prospective, institutional review board–approved study. After a single 18F-FDG injection, patients consecutively underwent 18F-FDG PET[Fraction Slash]CT and 18F-FDG PET/MR on the same day for staging or restaging. Three sets of images were analyzed separately: 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR with DWI. Region-based agreement and examination-based sensitivity and specificity were calculated for 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR DWI. Maximum and mean standardized uptake values (SUVmax, SUVmean) on 18F-FDG PET/CT and 18F-FDG PET/MR were compared and correlated with minimum and mean apparent diffusion coefficients (ADCmin, ADCmean). ResultsThirty-four patients with a total of 40 examinations were included. Examination-based sensitivities for 18F-FDG PET/CT, 18F-FDG PET/MR, and 18F-FDG PET/MR DWI were 82.1%, 85.7%, and 100%, respectively; specificities were 100% for all 3 techniques; and accuracies were 87.5%, 90%, and 100%, respectively. 18F-FDG PET/CT was false negative in 5 of 40 examinations (all with mucosa-associated lymphoid tissue lymphoma), and 18F-FDG PET/MR (without DWI) was false negative in 4 of 40 examinations. Region-based percentages of agreement were 99% (&kgr;, 0.95) between 18F-FDG PET/MR DWI and 18F-FDG PET/CT, 99.2% (&kgr;, 0.96) between 18F-FDG PET/MR and 18F-FDG PET/CT, and 99.4% (&kgr;, 0.97) between 18F-FDG PET/MR DWI and 18F-FDG PET/MR. There was a strong correlation between 18F-FDG PET/CT and 18F-FDG PET/MR for SUVmax (r = 0.83) and SUVmean (r = 0.81) but no significant correlation between ADCmin and SUVmax (18F-FDG PET/CT: r = 0.46, P = 0.65; 18F-FDG PET/MR: r = 0.64, P = 0.53) or between ADCmean and SUVmean (respectively, r = −0.14, P = 0.17 for the correlation with PET/CT and r = −0.14, P = 0.14 for the correlation with PET/MR). Conclusions18F-FDG PET/MR and 18F-FDG PET/CT show a similar diagnostic performance in lymphoma patients. However, if DWI is included in the 18F-FDG PET/MR protocol, results surpass those of 18F-FDG PET/CT because of the higher sensitivity of DWI for mucosa-associated lymphoid tissue lymphomas.


Endoscopy | 2016

Pediatric gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) and European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Guideline Executive summary

Andrea Tringali; Mike Thomson; Jean-Marc Dumonceau; Marta Tavares; Merit M. Tabbers; Raoul I. Furlano; Manon Spaander; Cesare Hassan; Christos Tzvinikos; Hanneke IJsselstijn; Jérôme Viala; Luigi Dall’Oglio; Marc A. Benninga; Rok Orel; Yvan Vandenplas; Radan Keil; Claudio Romano; Eva Brownstone; Štěpán Hlava; Patrick Gerner; Werner Dolak; R. Landi; Wolf Dietrich Huber; Simon Everett; Andreas Vécsei; Lars Aabakken; Jorge Amil-Dias; A. Zambelli

This Executive summary of the Guideline on pediatric gastrointestinal endoscopy from the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) refers to infants, children, and adolescents aged 0 - 18 years. The areas covered include: indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; endoscopic management of corrosive ingestion and stricture/stenosis; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease (IBD) have been dealt with in other Guidelines and are therefore not mentioned in this Guideline. Training and ongoing skill maintenance will be addressed in an imminent sister publication.


Journal of Pediatric Gastroenterology and Nutrition | 2017

Pediatric Gastrointestinal Endoscopy: European Society of Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) and European Society of Gastrointestinal Endoscopy (ESGE) Guidelines

Mike Thomson; Andrea Tringali; Jean-Marc Dumonceau; Marta Tavares; Merit M. Tabbers; Raoul I. Furlano; Manon Spaander; Cesare Hassan; Christos Tzvinikos; Hanneke IJsselstijn; Jérôme Viala; Luigi Dall'Oglio; Marc A. Benninga; Rok Orel; Yvan Vandenplas; Radan Keil; Claudio Romano; Eva Brownstone; Štěpán Hlava; Patrick Gerner; Werner Dolak; Rosario Landi; Wolf Dietrich Huber; Simon Everett; Andreas Vécsei; Lars Aabakken; Jorge Amil-Dias; A. Zambelli

This guideline refers to infants, children, and adolescents ages 0 to 18 years. The areas covered include indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography; and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease has been dealt with in other guidelines and are therefore not mentioned in this guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this.


Clinical Nuclear Medicine | 2016

Can Interim 18F-FDG PET or Diffusion-Weighted MRI Predict End-of-Treatment Outcome in FDG-Avid MALT Lymphoma After Rituximab-Based Therapy?: A Preliminary Study in 15 Patients.

Marius E. Mayerhoefer; Georgios Karanikas; Kurt Kletter; Barbara Kiesewetter; Michael Weber; Ivo Rausch; Matthias Pones; Ingrid Simonitsch-Klupp; Leonhard Müllauer; Werner Dolak; Julius Lukas; Markus Raderer

Purpose To determine whether interim 18F-FDG PET or interim diffusion-weighted magnetic resonance imaging (DWI) can predict the end-of-treatment (EOT) outcome after immunotherapy in patients with FDG-avid extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT). Materials and Methods Patients with untreated MALT lymphoma prospectively underwent whole-body 18F-FDG PET/CT and DWI before treatment (baseline), and after three cycles (interim) of rituximab-based immunotherapy. Maximum and mean standardized uptake values (SUVmax, SUVmean), and minimum and mean apparent diffusion coefficients (ADCmin, ADCmean), were measured for up to three target lesions per patient. Rates of change between baseline and interim examinations (&Dgr;SUVmax, &Dgr;SUVmean, &Dgr;ADCmin, and &Dgr;ADCmean) were compared, using ANOVAs, between the four end-of-treatment (EOT, after six cycles of immunotherapy) outcomes: complete remission (CR), partial remission (PR), stable disease (SD), or progressive disease (PD). Results Fifteen patients with 25 lesions were included. Lesion-based post hoc tests showed significant differences between CR and PR for &Dgr;SUVmax (P < 0.001), &Dgr;SUVmean (P < 0.001), and &Dgr;ADCmin (P = 0.044), and between CR and SD for &Dgr;SUVmax (P < 0.001), &Dgr;SUVmean (P < 0.001), &Dgr;ADCmin (P = 0.021), and &Dgr;ADCmean (P = 0.022). No lesion showed PD at EOT. Conclusions Both quantitative interim 18F-FDG PET and interim DWI may possibly be useful to predict complete remission at end-of-treatment in MALT lymphoma patients after immunotherapy.


Oncologist | 2016

Delayed Efficacy After Treatment With Lenalidomide or Thalidomide in Patients With Mucosa-Associated Lymphoid Tissue Lymphoma

Barbara Kiesewetter; Marlene Troch; Marius E. Mayerhoefer; Werner Dolak; Ingrid Simonitsch-Klupp; Markus Raderer

BACKGROUND The immunomodulatory drugs (IMiDs) thalidomide and lenalidomide have both been tested for treatment of mucosa-associated lymphoid tissue (MALT) lymphoma, with lenalidomide, in particular, showing promising activity. However, long-term results are missing. Because of the late-onset remissions registered in individual patients, we have systemically analyzed the patients treated with IMiDs at our institution for long-term results. METHODS Within the present retrospective analysis, we identified 25 patients who had been treated with lenalidomide (n = 18) or thalidomide (n = 7) and were available for long-term assessments of outcome. All patients were followed up according to a standardized follow-up protocol. RESULTS Of the 25 patients, 7 (28%) experienced delayed-onset responses without further treatment (thalidomide, n = 2; lenalidomide, n = 5). In 4 patients (16%), the initial outcome switched to a better result (partial remission [PR] to complete remission [CR], n = 1; stable disease [SD] to PR, n = 1; SD to CR, n = 1; and PD to CR, n = 1) after a median time of 19.5 months (range, 10.9-32.0). Furthermore, 2 patients showed ongoing shrinkage of the target lesion for 47.4+ and 43.5+ months, respectively, and 1 patient had durable disease stabilization for 16.2+ months. The median time to the best response for all responding patients (13 of 25; 53%) was 7.3 months (interquartile range [IQR], 5.6-22.5). After a median follow-up of 46 months (IQR, 32.0-58.5), 23 of 25 patients (92%) were alive. CONCLUSION Our findings suggest that late-onset remissions might be a common phenomenon in the use of IMiDs for the treatment of MALT lymphoma. Thus, sufficient follow-up time after treatment before the initiation of further therapy appears crucial to assess the full effect of therapy and avoid unnecessary overtreatment. IMPLICATIONS FOR PRACTICE The immunomodulatory drugs (IMiDs) thalidomide and lenalidomide have been tested for the treatment of mucosa-associated lymphoid tissue (MALT) lymphoma, with lenalidomide showing promising activity. However, long-term results are missing. The present findings suggest that late-onset remissions and delayed responses could be a common phenomenon with IMiD use for MALT lymphoma. Using a standardized restaging protocol to ensure concise follow-up data, these findings suggest it is of major importance to ensure a sufficient follow-up time after treatment with these compounds and before initiation of further treatment lines, because nearly one third of treated patients showed further improvement during prolonged follow-up.


Clinical Nuclear Medicine | 2016

Does Delayed-Time-Point Imaging Improve 18F-FDG-PET in Patients With MALT Lymphoma?: Observations in a Series of 13 Patients.

Marius E. Mayerhoefer; Chiara Giraudo; Daniela Senn; Markus Hartenbach; Michael Weber; Ivo Rausch; Barbara Kiesewetter; Christian J. Herold; Marcus Hacker; Matthias Pones; Ingrid Simonitsch-Klupp; Leonhard Müllauer; Werner Dolak; Julius Lukas; Markus Raderer

Purpose To determine whether in patients with extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue lymphoma (MALT), delayed–time-point 2-18F-fluoro-2-deoxy-d-glucose-positron emission tomography (18F-FDG-PET) performs better than standard–time-point 18F-FDG-PET. Materials and Methods Patients with untreated histologically verified MALT lymphoma, who were undergoing pretherapeutic 18F-FDG-PET/computed tomography (CT) and consecutive 18F-FDG-PET/magnetic resonance imaging (MRI), using a single 18F-FDG injection, in the course of a larger-scale prospective trial, were included. Region-based sensitivity and specificity, and patient-based sensitivity of the respective 18F-FDG-PET scans at time points 1 (45–60 minutes after tracer injection, TP1) and 2 (100–150 minutes after tracer injection, TP2), relative to the reference standard, were calculated. Lesion-to-liver and lesion-to-blood SUVmax (maximum standardized uptake values) ratios were also assessed. Results 18F-FDG-PET at TP1 was true positive in 15 o f 23 involved regions, and 18F-FDG-PET at TP2 was true-positive in 20 of 23 involved regions; no false-positive regions were noted. Accordingly, region-based sensitivities and specificities were 65.2% (confidence interval [CI], 45.73%–84.67%) and 100% (CI, 100%-100%) for 18F-FDG-PET at TP1; and 87.0% (CI, 73.26%–100%) and 100% (CI, 100%-100%) for 18F-FDG-PET at TP2, respectively. FDG-PET at TP1 detected lymphoma in at least one nodal or extranodal region in 7 of 13 patients, and 18F-FDG-PET at TP2 in 10 of 13 patients; accordingly, patient-based sensitivity was 53.8% (CI, 26.7%–80.9%) for 18F-FDG-PET at TP1, and 76.9% (CI, 54.0%–99.8%) for 18F-FDG-PET at TP2. Lesion-to-liver and lesion-to-blood maximum standardized uptake value ratios were significantly lower at TP1 (ratios, 1.05 ± 0.40 and 1.52 ± 0.62) than at TP2 (ratios, 1.67 ± 0.74 and 2.56 ± 1.10; P = 0.003 and P = 0.001). Conclusions Delayed–time-point imaging may improve 18F-FDG-PET in MALT lymphoma.

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Michael Trauner

Medical University of Vienna

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Markus Raderer

Medical University of Vienna

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Barbara Kiesewetter

Medical University of Vienna

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Andreas Püspök

Medical University of Vienna

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Julius Lukas

Medical University of Vienna

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Barbara Tribl

Medical University of Vienna

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