Search

Your search keyword '"Schimek-Jasch, T."' showing total 143 results
Start Over Author "Schimek-Jasch, T."
143 results on '"Schimek-Jasch, T."'

4. Evaluation of prognostic factors after primary chemoradiotherapy of anal cancer: A multicenter study of the German Cancer Consortium- Radiation Oncology Group (DKTK-ROG)

Author

Martin, D., Schreckenbach, T., Ziegler, P., Filmann, N., Kalinauskaite, G., Tinhofer, I., Budach, V., Gani, C., Zips, D., Schimek-Jasch, T., Schäfer, H., Grosu, A. L., Thomas, E., Krause, M., Dapper, H., Combs, S., Hoffmann, C., Stuschke, M., Walter, F., Belka, C., Kurth, I., Hadiwikarta, W. W., Baumann, M., Rödel, C., Fokas, E., Martin, D., Schreckenbach, T., Ziegler, P., Filmann, N., Kalinauskaite, G., Tinhofer, I., Budach, V., Gani, C., Zips, D., Schimek-Jasch, T., Schäfer, H., Grosu, A. L., Thomas, E., Krause, M., Dapper, H., Combs, S., Hoffmann, C., Stuschke, M., Walter, F., Belka, C., Kurth, I., Hadiwikarta, W. W., Baumann, M., Rödel, C., and Fokas, E.

Abstract

Background and purpose: Prognosis after chemoradiotherapy (CRT) for anal squamous cell carcinoma (ASCC) shows marked differences among patients according to TNM subgroups, however individualized risk assessment tools to better stratify patients for treatment (de-) escalation or intensified follow-up are lacking in ASCC. Materials and methods: Patients’ data from eight sites of the German Cancer Consortium - Radiation Oncology Group (DKTK-ROG), comprising a total of 605 patients with ASCC, treated with standard defini- tive CRT with 5-FU/Mitomycin C or Capecitabine/Mitomycin C between 2004–2018, were used to evalu- ate prognostic factors based on Cox regression models for disease-free survival (DFS). Evaluated variables included age, gender, Karnofsky performance score (KPS), HIV-status, T-category, lymph node status and laboratory parameters. Multivariate cox models were separately constructed for the whole cohort and the subset of patients with early-stage (cT1-2 N0M0) tumors. Results: After a median follow-up of 46 months, 3-year DFS for patients with early-stage ASCC was 84.9%, and 67.1% for patients with locally-advanced disease (HR 2.4, p < 0.001). T-category (HR vs. T1: T2 2.02; T3 2.11; T4 3.03), N-category (HR versus N0: 1.8 for N1-3), age (HR 1.02 per year), and KPS (HR 0.8 per step) were significant predictors for DFS in multivariate analysis in the entire cohort. The model per- formed with a C-index of 0.68. In cT1-2N0 patients, T-category (HR 2.14), HIV status (HR 2.57), age (1.026 per year), KPS (HR 0.7 per step) and elevated platelets (HR 1.3 per 100/nl) were associated with worse DFS (C-index of 0.7). Conclusion: Classical clinicopathologic parameters like T-category, N-category, age and KPS remain to be significant prognostic factors for DFS in patients treated with contemporary CRT for ASCC. HIV and plate- lets were significantly associated with worse DFS in patients with early stage ASCC.

Published
2022

5. Evaluation of prognostic factors after primary chemoradiotherapy of anal cancer: A multicenter study of the German Cancer Consortium-Radiation Oncology Group (DKTK-ROG)

Author

Martin, D., primary, Schreckenbach, T., additional, Ziegler, P., additional, Filmann, N., additional, Kalinauskaite, G., additional, Tinhofer, I., additional, Budach, V., additional, Gani, C., additional, Zips, D., additional, Schimek-Jasch, T., additional, Schäfer, H., additional, Grosu, A.L., additional, Thomas, E., additional, Krause, M., additional, Dapper, H., additional, Combs, S., additional, Hoffmann, C., additional, Stuschke, M., additional, Walter, F., additional, Belka, C., additional, Kurth, I., additional, Hadiwikarta, W.W, additional, Baumann, M., additional, Rödel, C., additional, and Fokas, E., additional

Published
2022
Full Text
View/download PDF

6. The Impact of Radiotherapy Protocol Adherence on the Treatment Outcome in Patients With Locally Advanced NSCLC Treated With Concurrent Chemoradiation: Results From the Radiotherapy Quality Assurance of the International Randomized PET-Plan Trial

Author

Gkika, E., primary, Schimek-Jasch, T., additional, Kremp, S., additional, Lenz, S., additional, Schaefer-Schuler, A., additional, Mix, M., additional, Kuesters, A., additional, Tosch, M., additional, Hehr, T., additional, Eschmann, S., additional, Bultel, Y.P., additional, Hass, P., additional, Fleckenstein, J., additional, Thieme, A., additional, Stockinger, M., additional, Dieckmann, K., additional, Miederer, M., additional, Holl, G., additional, Rischke, H.C., additional, Adebahr, S., additional, Koenig, J., additional, Binder, H., additional, Grosu, A.L., additional, and Nestle, U., additional

Published
2021
Full Text
View/download PDF

8. FDG-PET Radiomics for Response Monitoring in Non-Small-Cell Lung Cancer Treated with Radiation Therapy

Author

Carles M, Fechter T, Radicioni G, Schimek-Jasch T, Adebahr S, Zamboglou C, Nicolay NH, Martí-Bonmatí L, Nestle U, Grosu AL, Baltas D, Mix M, and Gkika E

Subjects
FDG monitoring and retrospectively gated 4D PET/CT, PET radiomics, lung cancer
Abstract

The aim of this study is to identify clinically relevant image feature (IF) changes during chemoradiation and evaluate their efficacy in predicting treatment response. Patients with non-small-cell lung cancer (NSCLC) were enrolled in two prospective trials (STRIPE, PET-Plan). We evaluated 48 patients who underwent static (3D) and retrospectively-respiratory-gated 4D PET/CT scans before treatment and a 3D scan during or after treatment. Our proposed method rejects IF changes due to intrinsic variability. The IF variability observed across 4D PET is employed as a patient individualized normalization factor to emphasize statistically relevant IF changes during treatment. Predictions of overall survival (OS), local recurrence (LR) and distant metastasis (DM) were evaluated. From 135 IFs, only 17 satisfied the required criteria of being normally distributed across 4D PET and robust between 3D and 4D images. Changes during treatment in the area-under-the-curve of the cumulative standard-uptake-value histogram (d AUC CSH ) within primary tumor discriminated (AUC = 0.87, Specificity = 0.78) patients with and without LR. The resulted prognostic model was validated with a different segmentation method (AUC = 0.83) and in a different patient cohort (AUC = 0.63). The quantification of tumor FDG heterogeneity by d AUC CSH during chemoradiation correlated with the incidence of local recurrence and might be recommended for monitoring treatment response in patients with NSCLC.

Published
2021

13. Immunohistochemistry and Radiomics Features for Survival Prediction in Small Cell Lung Cancer

Author

Gkika, E., primary, Benndorf, M., additional, Oerther, B., additional, Mohammad, F., additional, Beitinger, S., additional, Adebahr, S., additional, Carles, M., additional, Schimek-Jasch, T., additional, Zamboglou, C., additional, Frye, B.C., additional, Bamberg, F., additional, Waller, C., additional, Grosu, A., additional, Nestle, U., additional, and Kayser, G., additional

Published
2020
Full Text
View/download PDF

15. OC-0231: Outcome impact of radiotherapy protocol compliance: RTQA results from the PET-Plan trial

Author

Schimek-Jasch, T., primary, Kremp, S., additional, Stockinger, M., additional, Küsters, A., additional, Hehr, T., additional, Bultel, Y., additional, Hass, P., additional, Fleckenstein, J., additional, Thieme, A.H., additional, Adebahr, S., additional, Gkika, E., additional, Duncker-Rohr, V., additional, Tosch, M., additional, Eschmann, S.M., additional, Miederer, M., additional, Holl, G., additional, Rischke, H.C., additional, Schaefer-Schuler, A., additional, König, J., additional, Broichhagen, C., additional, Lenz, S., additional, Binder, H., additional, Grosu, A., additional, and Nestle, U., additional

Published
2020
Full Text
View/download PDF

16. The Role of Different Chemotherapy Protocols for Concurrent CRT in Locally Advanced NSCLC

Author

Gkika, E., primary, Schimek-Jasch, T., additional, Kremp, S., additional, Schaefer-Schuler, A., additional, Mix, M., additional, Kuesters, A., additional, Tosch, M., additional, Hehr, T., additional, Eschmann, S., additional, Bultel, Y.P., additional, Hass, P., additional, Fleckenstein, J., additional, Thieme, A., additional, Stockinger, M., additional, Dieckmann, K., additional, Miederer, M., additional, Holl, G., additional, Rischke, H.C., additional, Adebahr, S., additional, Broichhagen, C., additional, Lenz, S., additional, Koenig, J., additional, Binder, H., additional, Grosu, A., additional, and Nestle, U., additional

Published
2020
Full Text
View/download PDF

17. Challenges and caveats of a multi-center retrospective radiomics study: An example of early treatment response assessment for NSCLC patients using FDG-PET/CT radiomics

Author

Timmeren, J.-E., Carvalho, S., Leijenaar, R. T. H., Troost, E. G. C., Elmpt, W., Ruysscher, D., Muratet, J. P., Denis, F., Schimek-Jasch, T., Nestle, U., Jochems, A., Woodruff, H. C., Oberije, C., Lambin, P., Timmeren, J.-E., Carvalho, S., Leijenaar, R. T. H., Troost, E. G. C., Elmpt, W., Ruysscher, D., Muratet, J. P., Denis, F., Schimek-Jasch, T., Nestle, U., Jochems, A., Woodruff, H. C., Oberije, C., and Lambin, P.

Abstract

Background Prognostic models based on individual patient characteristics can improve treatment decisions and outcome in the future. In many (radiomic) studies, small size and heterogeneity of datasets is a challenge that often limits performance and potential clinical applicability of these models. The current study is example of a retrospective multi-centric study with challenges and caveats. To highlight common issues and emphasize potential pitfalls, we aimed for an extensive analysis of these multi-center pre-treatment datasets, with an additional 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/ CT) scan acquired during treatment. Methods The dataset consisted of 138 stage II-IV non-small cell lung cancer (NSCLC) patients from four different cohorts acquired from three different institutes. The differences between the cohorts were compared in terms of clinical characteristics and using the so-called ‘cohort differences model’ approach. Moreover, the potential prognostic performances for overall survival of radiomic features extracted from CT or FDG-PET, or relative or absolute differences between the scans at the two time points, were assessed using the LASSO regression method. Furthermore, the performances of five different classifiers were evaluated for all image sets. Results The individual cohorts substantially differed in terms of patient characteristics. Moreover, the cohort differences model indicated statistically significant differences between the cohorts. Neither LASSO nor any of the tested classifiers resulted in a clinical relevant prognostic model that could be validated on the available datasets. Conclusion The results imply that the study might have been influenced by a limited sample size, heterogeneous patient characteristics, and inconsistent imaging parameters. No prognostic performance of FDG-PET or CT based radiomics models can be reported. This study highlights the necessity of extensive evaluations of co

Published
2019

18. OA12.05 Imaging-Guided Target Volume Reduction in Radiotherapy of Lung Cancer: The Prospective Randomized Multinational PET-Plan Trial

Author

Nestle, U., primary, Schimek-Jasch, T., additional, Kremp, S., additional, Schaefer, A., additional, Kuesters, A., additional, Tosch, M., additional, Hehr, T., additional, Eschmann, M., additional, Bultel, Y., additional, Hass, P., additional, Fleckenstein, J., additional, Thieme, A., additional, Stockinger, M., additional, Miederer, M., additional, Holl, G., additional, Rischke, C., additional, Adebahr, S., additional, Gkika, E., additional, Koenig, J., additional, and Grosu, A., additional

Published
2019
Full Text
View/download PDF

21. Locally Advanced Non-Small Cell Lung Cancer: Excellent Results of Isotoxic Dose Escalation after FDG-PET-Guided Target Volume Reduction – Results of a Prospective Randomized Multicenter Trial

Author

Nestle, U., primary, Schimek-Jasch, T., additional, Kremp, S., additional, Schaefer-Schuler, A., additional, Kuesters, A., additional, Tosch, M., additional, Hehr, T., additional, Eschmann, S., additional, Bultel, Y.P., additional, Hass, P., additional, Jochen, F., additional, Thieme, A., additional, Stockinger, M., additional, Beck, M., additional, Miederer, M., additional, Holl, G., additional, Rischke, H.C., additional, Adebahr, S., additional, Koenig, J., additional, and Grosu, A., additional

Published
2018
Full Text
View/download PDF

24. OC-0598: FDG-PET-guided target volume reduction for isotoxic dose escalation in LA NSCLC (PET-Plan study)

Author

Nestle, U., primary, Schimek-Jasch, T., additional, Kremp, S., additional, Schaefer-Schuler, A., additional, Kuesters, A., additional, Tosch, M., additional, Hehr, T., additional, Eschmann, S., additional, Bultel, Y., additional, Hass, P., additional, Brunner, T., additional, Fleckenstein, J., additional, Thieme, A., additional, Stockinger, M., additional, Miederer, M., additional, Beck, M., additional, Holl, G., additional, Rischke, H., additional, Adebahr, S., additional, Lenz, S., additional, Koenig, J., additional, and Grosu, A., additional

Published
2018
Full Text
View/download PDF

25. Using GOMS and NASA-TLX to Evaluate Human–Computer Interaction Process in Interactive Segmentation

Author

Ramkumar, A. (Anjana), Stappers, P.J. (P.), Niessen, W.J. (Wiro), Adebahr, S. (Sonja), Schimek-Jasch, T. (Tanja), Nestle, U. (Ursula), Song, Y. (Yu), Ramkumar, A. (Anjana), Stappers, P.J. (P.), Niessen, W.J. (Wiro), Adebahr, S. (Sonja), Schimek-Jasch, T. (Tanja), Nestle, U. (Ursula), and Song, Y. (Yu)

Abstract

HCI plays an important role in interactive medical image segmentation. The Goals, Operators, Methods, and Selection rules (GOMS) model and the National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire are different methods that are often used to evaluate the HCI process. In this article, we aim at improving the HCI process of interactive segmentation using both the GOMS model and the NASA-TLX questionnaire to: 1) identify the relations between these two methods and 2) propose HCI design suggestions based on the synthesis of the evaluation r

Published
2017
Full Text
View/download PDF

30. User Interaction in Semi-Automatic Segmentation of Organs at Risk: a Case Study in Radiotherapy

Author

Ramkumar, A. (Anjana), Dolz, J. (Jose), Kirisli, H.A. (Hortense), Adebahr, S. (Sonja), Schimek-Jasch, T. (Tanja), Nestle, U. (Ursula), Massoptier, L. (Laurent), Varga, E. (Edit), Stappers, P.J. (P.), Niessen, W.J. (Wiro), Song, Y. (Yu), Ramkumar, A. (Anjana), Dolz, J. (Jose), Kirisli, H.A. (Hortense), Adebahr, S. (Sonja), Schimek-Jasch, T. (Tanja), Nestle, U. (Ursula), Massoptier, L. (Laurent), Varga, E. (Edit), Stappers, P.J. (P.), Niessen, W.J. (Wiro), and Song, Y. (Yu)

Abstract

Accurate segmentation of organs at risk is an important step in radiotherapy planning. Manual segmentation being a tedious procedure and prone to inter- and intra-observer variability, there is a growing interest in automated segmentation methods. However, automatic methods frequently fail to provide satisfactory result, and post-processing corrections are often needed. Semi-automatic segmentation methods are designed to overcome these problems by combining physicians’ expertise and computers’ potential. This study evaluates two semi-automatic segmentation methods with different types of user interactions, named the “strokes” and the “contour”, to provide insights into the role and impact of human-computer interaction. Two physicians participated in the experiment. In total, 42 case studies were carried out on five different types of organs at risk. For each case study, both the human-computer interaction process and quality of the segmentation results were measured subjectively and objectively. Furthermore, different measures of the process and the results were correlated. A total of 36 quantifiable and ten non-quantifiable correlations were identified for each type of interaction. Among those pairs of measures, 20 of the contour method and 22 of the strokes method were strongly or moderately correlated, either directly or inversely. Based on those correlated measures, it is concluded that: (1) in the design of semi-automatic segmentation methods, user interactions need to be less cognitively challenging; (2) based on the observed workflows and preferences of physicians, there is a need for flexibility in the interface design; (3) the correlated measures provide insights that can be used in improving user interaction design.

Published
2016
Full Text
View/download PDF

41. User Interaction in Semi-Automatic Segmentation of Organs at Risk: A Case Study in Radiotherapy

Author

Ramkumar, A. (author), Dolz, J. (author), Kirisli, H.A. (author), Adebahr, S. (author), Schimek-Jasch, T. (author), Nestle, U. (author), Massoptier, L. (author), Varga, E. (author), Stappers, P.J. (author), Niessen, W.J. (author), Song, Y. (author), Ramkumar, A. (author), Dolz, J. (author), Kirisli, H.A. (author), Adebahr, S. (author), Schimek-Jasch, T. (author), Nestle, U. (author), Massoptier, L. (author), Varga, E. (author), Stappers, P.J. (author), Niessen, W.J. (author), and Song, Y. (author)

Abstract

Accurate segmentation of organs at risk is an important step in radiotherapy planning. Manual segmentation being a tedious procedure and prone to inter- and intra-observer variability, there is a growing interest in automated segmentation methods. However, automatic methods frequently fail to provide satisfactory result, and post-processing corrections are often needed. Semi-automatic segmentation methods are designed to overcome these problems by combining physicians’ expertise and computers’ potential. This study evaluates two semi-automatic segmentation methods with different types of user interactions, named the “strokes” and the “contour”, to provide insights into the role and impact of human-computer interaction. Two physicians participated in the experiment. In total, 42 case studies were carried out on five different types of organs at risk. For each case study, both the human-computer interaction process and quality of the segmentation results were measured subjectively and objectively. Furthermore, different measures of the process and the results were correlated. A total of 36 quantifiable and ten non-quantifiable correlations were identified for each type of interaction. Among those pairs of measures, 20 of the contour method and 22 of the strokes method were strongly or moderately correlated, either directly or inversely. Based on those correlated measures, it is concluded that: (1) in the design of semi-automatic segmentation methods, user interactions need to be less cognitively challenging; (2) based on the observed workflows and preferences of physicians, there is a need for flexibility in the interface design; (3) the correlated measures provide insights that can be used in improving user interaction design., Design Engineering, Industrial Design Engineering

Published
2015

45. Stereotaktische Strahlentherapie (SBRT) beim wiederkehrenden oder oligometastatischen Pankreaskarzinom : Bewertung der Toxizität bei simultan integrierter Protektion (SIP) versus konventioneller SBRT.

Author

Gkika, E., Adebahr, S., Kirste, S., Schimek-Jasch, T., Wiehle, R., Claus, R., Wittel, U., Nestle, U., Baltas, D., Grosu, A., Brunner, T., Grosu, A L, and Brunner, T B

Subjects
ADENOCARCINOMA, HUMAN body, CANCER relapse, CLINICAL trials, COMBINED modality therapy, COMPARATIVE studies, COMPUTED tomography, HEALTH, LONGITUDINAL method, MAGNETIC resonance imaging, RESEARCH methodology, MEDICAL cooperation, COMPUTERS in medicine, METASTASIS, PANCREATIC tumors, RADIATION, RADIATION doses, RADIOSURGERY, RADIOTHERAPY, RESEARCH, SURVIVAL analysis (Biometry), TUMOR classification, EVALUATION research, RETROSPECTIVE studies, DISEASE progression
Abstract

Copyright of Strahlentherapie und Onkologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2017
Full Text
View/download PDF

49. Measuring inter-observer agreement in contour delineation of medical imaging in a dummy run using Fleiss' kappa.

Author

Rücker G, Schimek-Jasch T, Nestle U, Rücker, G, Schimek-Jasch, T, and Nestle, U

Abstract

Background: In medical imaging used for planning of radiation therapy, observers delineate contours of a treatment volume in a series of images of uniform slice thickness.Objective: To summarize agreement in contouring between an arbitrary number of observers by a single number, we generalized the kappa index proposed by Zijdenbos et al. (1994).Methods: Observers characterized voxels by allocating them to one of two categories, inside or outside the contoured region. Fleiss' kappa was used to measure association between n indistinguishable observers. Given the number Vi of voxels contoured by exactly i observers (i = 1, ..., n ), the resulting overall kappa is representable as a ratio of weighted sums of the Vi .Results: Overall kappa was applied to analyze inter-center variations in a multicenter trial on radiotherapy planning in patients with locally advanced lung cancer. A contouring dummy run was performed within the quality assurance program. Contouring was done twice, once before and once after a training program. Observer agreement was enhanced from 0.59 (with a 95% confidence interval (CI) of 0.51-0.67) to 0.69 (95% CI 0.59-0.78).Conclusion: By contrast to average pairwise indices, overall kappa measures observer agreement for more than two observers using the full information about overlapping volumes, while not distinguishing between observers. It is particularly adequate for measuring observer agreement when identification of observers is not possible or desirable and when there is no gold standard. [ABSTRACT FROM AUTHOR]

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results