| 1. |
- Tzikas, Apostolos, et al.
(författare)
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Percutaneous left atrial appendage occlusion : the Munich consensus document on definitions, endpoints, and data collection requirements for clinical studies
- 2017
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Ingår i: Europace. - : OXFORD UNIV PRESS. - 1099-5129 .- 1532-2092. ; 19:1, s. 4-15
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Tidskriftsartikel (refereegranskat)abstract
- The increasing interest in left atrial appendage occlusion (LAAO) for ischaemic stroke prevention in atrial fibrillation (AF) fuels the need for more clinical data on the safety and effectiveness of this therapy. Besides an assessment of the effectiveness of the therapy in specific patients groups, comparisons with pharmacological stroke prophylaxis, surgical approaches, and other device-based therapies are warranted. This paper documents the consensus reached among clinical experts in relevant disciplines from Europe and North America, European cardiology professional societies, and representatives from the medical device industry regarding definitions for parameters and endpoints to be assessed in clinical studies. Adherence to these definitions is proposed in order to achieve a consistent approach across clinical studies on LAAO among the involved stakeholders and various clinical disciplines and thereby facilitate continued evaluation of therapeutic strategies available.
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| 2. |
- Tzikas, Apostolos, et al.
(författare)
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Percutaneous left atrial appendage occlusion : the Munich consensus document on definitions, endpoints and data collection requirements for clinical studies
- 2016
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Ingår i: EuroIntervention. - 1774-024X .- 1969-6213. ; 12:1, s. 103-111
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Tidskriftsartikel (refereegranskat)abstract
- The increasing interest in left atrial appendage occlusion (LAAO) for ischaemic stroke prevention in atrial fibrillation (AF) fuels the need for more clinical data on the safety and effectiveness of this therapy. Besides an assessment of the effectiveness of the therapy in specific patient groups, comparisons with pharmacological stroke prophylaxis, surgical approaches and other device-based therapies are warranted. This paper documents the consensus reached among clinical experts in relevant disciplines from Europe and North America, European cardiology professional societies and representatives from the medical device industry regarding defmitions for parameters and endpoints to be assessed in clinical studies. Adherence to these definitions is proposed in order to achieve a consistent approach across clinical studies on LAAO among the involved stakeholders and various clinical disciplines and thereby facilitate continued evaluation of therapeutic strategies available.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Mavroidis, P, et al.
(författare)
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Toolkit for determination of dose-response relations, validation of radiobiological parameters and treatment plan optimization based on radiobiological measures
- 2010
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Ingår i: Technology in cancer research & treatment. - : SAGE Publications. - 1533-0338 .- 1533-0346. ; 9:5, s. 523-537
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Tidskriftsartikel (refereegranskat)abstract
- Accurately determined dose-response relations of the different tumors and normal tissues should be estimated and used in the clinic. The aim of this study is to demonstrate developed tools that are necessary for determining the dose-response parameters of tumors and normal tissues, for clinically verifying already published parameter sets using local patient materials and for making use of all this information in the optimization and comparison of different treatment plans and radiation techniques. One of the software modules (the Parameter Determination Module) is designed to determine the dose-response parameters of tumors and normal tissues. This is accomplished by performing a maximum likelihood fitting to calculate the best estimates and confidence intervals of the parameters used by different radiobiological models. Another module of this software (the Parameter Validation Module) concerns the validation and compatibility of external or reported dose-response parameters describing tumor control and normal tissue complications. This is accomplished by associating the expected response rates, which are calculated using different models and published parameter sets, with the clinical follow-up records of the local patient population. Finally, the last module of the software (the Radiobiological Plan Evaluation Module) is used for estimating and optimizing the effectiveness a treatment plan in terms of complication-free tumor control, P+. The use of the Parameter Determination Module is demonstrated by deriving the dose-response relation of proximal esophagus from head & neck cancer radiotherapy. The application of the Parameter Validation Module is illustrated by verifying the clinical compatibility of those dose-response parameters with the examined treatment methodologies. The Radiobiological Plan Evaluation Module is demonstrated by evaluating and optimizing the effectiveness of head & neck cancer treatment plans. The results of the radiobiological evaluation are compared against dosimetric criteria. The presented toolkit appears to be very convenient and efficient for clinical implementation of radiobiological modeling. It can also be used for the development of a clinical data and health information database for assisting the performance of epidemiological studies and the collaboration between different institutions within research and clinical frameworks.
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| 7. |
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| 8. |
- Tzikas, A, et al.
(författare)
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Investigating the clinical aspects of using CT vs. CT-MRI images during organ delineation and treatment planning in prostate cancer radiotherapy
- 2011
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Ingår i: Technology in cancer research & treatment. - : SAGE Publications. - 1533-0338 .- 1533-0346. ; 10:3, s. 231-242
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Tidskriftsartikel (refereegranskat)abstract
- In order to apply highly conformal dose distributions, which are characterized by steep dose fall-offs, it is necessary to know the exact target location and extension. This study aims at evaluating the impact of using combined CT-MRI images in organ delineation compared to using CT images alone, on the clinical results. For 10 prostate cancer patients, the respective CT and MRI images at treatment position were acquired. The CTV was delineated using the CT and MRI images, separately, whereas bladder and rectum were delineated using the CT images alone. Based on the CT and MRI images, two CTVs were produced for each patient. The mutual information algorithm was used in the fusion of the two image sets. In this way, the structures drawn on the MRI images were transferred to the CT images in order to produce the treatment plans. For each set of structures of each patient, IMRT and 3D-CRT treatment plans were produced. The individual treatment plans were compared using the biologically effective uniform dose ([Formula: see text]) and the complication-free tumor control probability ( P+) concepts together with the DVHs of the targets and organs at risk and common dosimetric criteria. For the IMRT treatment, at the optimum dose level of the average CT and CT-MRI delineated CTV dose distributions, the P+ values are 74.7% in both cases for a [Formula: see text] of 91.5 Gy and 92.1 Gy, respectively. The respective average total control probabilities, PB are 90.0% and 90.2%, whereas the corresponding average total complication probabilities, PI are 15.3% and 15.4%. Similarly, for the 3D-CRT treatment, the average P+ values are 42.5% and 46.7%, respectively for a [Formula: see text] of 86.4 Gy and 86.7 Gy, respectively. The respective average PB values are 80.0% and 80.6%, whereas the corresponding average PI values are 37.4% and 33.8%, respectively. For both radiation modalities, the improvement mainly stems from the better sparing of rectum. According to these results, the expected clinical effectiveness of IMRT can be increased by a maximum Δ P+ of around 0.9%, whereas of 3D-CRT by about 4.2% when combined CT-MRI delineation is performed instead of using CT images alone. It is apparent that in both IMRT and 3D-CRT radiation modalities, the better knowledge of the CTV extension improved the produced dose distribution. It is shown that the CTV is irradiated more effectively, while the complication probabilities of bladder and rectum, which is the principal organs at risk, are lower in the CT-MRI based treatment plans.
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| 9. |
- Tzikas, A., et al.
(författare)
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Investigating the Clinical Aspects of Using CT vs. CT-MRI Images During Organ Delineation and Treatment Planning in Prostate Cancer Radiotherapy
- 2011
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Ingår i: Technology in Cancer Research & Treatment. - 1533-0346 .- 1533-0338. ; 10:3, s. 231-242
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Tidskriftsartikel (refereegranskat)abstract
- In order to apply highly conformal dose distributions, which are characterized by steep dose fall-offs, it is necessary to know the exact target location and extension. This study aims at evaluating the impact of using combined CT-MRI images in organ delineation compared to using CT images alone, on the clinical results. For 10 prostate cancer patients, the respective CT and MRI images at treatment position were acquired. The CTV was delineated using the CT and MRI images, separately, whereas bladder and rectum were delineated using the CT images alone. Based on the CT and MRI images, two CTVs were produced for each patient. The mutual information algorithm was used in the fusion of the two image sets. In this way, the structures drawn on the MRI images were transferred to the CT images in order to produce the treatment plans. For each set of structures of each patient, IMRT and 3D-CRT treatment plans were produced. The individual treatment plans were compared using the biologically effective uniform dose (D) and the complication-free tumor control probability (R) concepts together with the DVHs of the targets and organs at risk and common dosimetric criteria. For the IMRT treatment, at the optimum dose level of the average CT and CT-MRI delineated CTV dose distributions, the P. values are 74.7% in both cases for a D(CTV) of 91.5 Gy and 92.1 Gy, respectively. The respective average total control probabilities, P(B) are 90.0% and 90.2%, whereas the corresponding average total complication probabilities, P, are 15.3% and 15.4%. Similarly, for the 3D-CRT treatment, the average P. values are 42.5% and 46.7%, respectively for a D(CTV) of 86.4 Gy and 86.7 Gy, respectively. The respective average PB values are 80.0% and 80.6%, whereas the corresponding average P values are 37.4% and 33.8%, respectively. For both radiation modalities, the improvement mainly stems from the better sparing of rectum. According to these results, the expected clinical effectiveness of IMRT can be increased by a maximum Delta P, of around 0.9%, whereas of 3D-CRT by about 4.2% when combined CT-MRI delineation is performed instead of using CT images alone. It is apparent that in both IMRT and 3D-CRT radiation modalities, the better knowledge of the CTV extension improved the produced dose distribution. It is shown that the CTV is irradiated more effectively, while the complication probabilities of bladder and rectum, which is the principal organs at risk, are lower in the CT-MRI based treatment plans.
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