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  1. Book ; Thesis: Entwicklung hocheffizienter Bestrahlungsplanungsansätze für die Volumetrische Intensitätsmodulierte Arc Therapie (VMAT) komplexer Zielvolumina

    Stieler, Florian

    2011  

    Author's details vorgelegt von Florian Stieler
    Language German
    Size 84 Bl. : Ill., graph. Darst.
    Publishing country Germany
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Mannheim, Univ., Diss., 2011
    HBZ-ID HT017175182
    Database Catalogue ZB MED Medicine, Health

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  2. Article ; Conference proceedings: Automatic Three-Dimensional Reconstruction of the Esophagus in Achalasia Patients undergoing POEM: a Comprehensive Assessment of Treatment Outcomes and pathophysiological Changes

    Nagl, S. / Grünherz, V. / Elia, M. / Stieler, F. / Peter, T. / Bauer, B. / Muzalyova, A. / Messmann, H. / Ebigbo, A.

    Endoscopy

    2024  Volume 56, Issue S 02

    Event/congress ESGE Days 2024, Berlin, Germany, 2024-04-25
    Language English
    Publishing date 2024-04-01
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 80120-3
    ISSN 1438-8812 ; 0013-726X
    ISSN (online) 1438-8812
    ISSN 0013-726X
    DOI 10.1055/s-0044-1783095
    Database Thieme publisher's database

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  3. Article ; Online: Homogenous dose prescription in Gamma Knife Radiotherapy: Combining the best of both worlds.

    Spaniol, Manon / Abo-Madyan, Yasser / Ruder, Arne M / Fleckenstein, Jens / Giordano, Frank A / Stieler, Florian

    Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)

    2023  Volume 117, Page(s) 103202

    Abstract: Purpose: Stereotactic radiosurgery with linear accelerators (LINACs) or Leksell Gamma Knife® (LGK, Elekta AB) is an established treatment option for intracranial tumors. When those are involving/abutting organs at risk (OAR), homogenous and ... ...

    Abstract Purpose: Stereotactic radiosurgery with linear accelerators (LINACs) or Leksell Gamma Knife® (LGK, Elekta AB) is an established treatment option for intracranial tumors. When those are involving/abutting organs at risk (OAR), homogenous and normofractionated treatments outmatch single fraction deliveries. In such situations, it would be desirable to balance LINAC's homogeneity benefits with LGK's dose gradient attributes. In this study, we determined homogeneity and OAR sparing ranges using a non-clinical, homogenous prototype version of LGK Lightning.
    Methods: We retrospectively analyzed thirty fractionated LGK Icon in-house patients with acoustic neuromas, pituitary adenomas and meningiomas. Four treatment plans were generated (54 Gy,1.8 Gy/fx) per patient: one LINAC plan, one clinical Lightning plan ("LGK") and two prototype Lightning plans ("LGK Hom" and "LGK OAR"). We analyzed D
    Results: While the LINAC vs. Lightning plans (LGK Hom|LGK OAR|LGK) boast better homogeneity (median: 1.08 vs. 1.18|1.24|1.35) and shorter BOT (median: 137 s vs. 432 s|510 s|510 s), Lightning plans show improved GI (median: 6.68 vs. 3.86|3.50|3.19), similar PCI (median: 0.75 vs. 0.76|0.75|0.82) and significantly reduced OAR doses. For in-tumor OAR, LGK Hom and LINAC plans achieves similar OAR sparing with improved GI for LGK Hom.
    Conclusions: This study is a preliminary attempt to combine the dosimetric advantages of LINAC and LGK treatment planning. We observed that LGK plan homogeneity can be improved toward LINAC standards while maintaining the LGK advantage of favorable OAR doses and GI. Additionally, in-tumor OAR hotspots can be considerably reduced.
    MeSH term(s) Humans ; Radiosurgery ; Retrospective Studies ; Brain Neoplasms/pathology ; Particle Accelerators ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Meningeal Neoplasms/surgery ; Radiotherapy, Intensity-Modulated
    Language English
    Publishing date 2023-12-29
    Publishing country Italy
    Document type Journal Article
    ZDB-ID 1122650-x
    ISSN 1724-191X ; 1120-1797
    ISSN (online) 1724-191X
    ISSN 1120-1797
    DOI 10.1016/j.ejmp.2023.103202
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Conference proceedings: Automatische dreidimensionale Rekonstruktion des Ösophagus zur Vorhersage des Therapieerfolges bei Patienten mit Achalasie

    Nagl, S. / Grünherz, V. / Elia, M. / Peter, T. / Stieler, F. / Bauer, B. / Messmann, H. / Ebigbo, A.

    Zeitschrift für Gastroenterologie

    2023  Volume 61, Issue 08

    Event/congress Viszeralmedizin 2023 77. Jahrestagung der DGVS mit Sektion Endoskopie Herbsttagung der Deutschen Gesellschaft für Allgemein- und Viszeralchirurgie mit den Arbeitsgemeinschaften der DGAV und Jahrestagung der CACP, Erst online. Dann Hamburg., 2023-09-11
    Language German
    Publishing date 2023-08-01
    Publisher Georg Thieme Verlag
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 201387-3
    ISSN 1439-7803 ; 0044-2771 ; 0172-8504
    ISSN (online) 1439-7803
    ISSN 0044-2771 ; 0172-8504
    DOI 10.1055/s-0043-1771956
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  5. Article ; Online: Inverse planning in Gamma Knife radiosurgery: A comparative planning study.

    Spaniol, Manon / Mai, Sabine / Zakrzewski, Tonja / Ehmann, Michael / Stieler, Florian

    Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)

    2021  Volume 82, Page(s) 269–278

    Abstract: Purpose: To determine the advantages of inverse planning using a prerelease version of Leksell Gamma Knife® (LGK) Lightning (Elekta AB, Sweden) compared to manual forward planning.: Methods: Thirty-eight patients with metastases (MET, n = 15), ... ...

    Abstract Purpose: To determine the advantages of inverse planning using a prerelease version of Leksell Gamma Knife® (LGK) Lightning (Elekta AB, Sweden) compared to manual forward planning.
    Methods: Thirty-eight patients with metastases (MET, n = 15), vestibular schwannomas (VS, n = 11) and meningiomas (MEN, n = 12), treated with LGK Icon™ at our institution, were analyzed retrospectively. For each case, an inverse (inv) and inverse full coverage (fc) treatment plan was generated using LGK Lightning and compared to the clinical plans. Several dosimetry and efficiency characteristics were compared for each indication. The mean, median difference and interquartile range were reported and the significance was assessed with a paired-sample Wilcoxon test (significance level < 0.05). Further, the inter operator variability was analyzed for multiple users.
    Results: Inv and fc treatment plans show improved target coverage (up to 3.6%) for all analyzed paradigms. For inv plans, the selectivity is enhanced (MET: 2.9%; VS: 1.8%; MEN: 1%) and the organ at risk doses are significantly reduced (VS: up to 4.5%; MEN: up to 17.5%). For inv and fc plans, the beam on time (BOT) is shortened (MET: up to 7.9%; benign tumors: 49.5%). The inter operator variability analysis shows similar treatment plan quality with small differences in plan efficiency (difference in BOT: 1-3.3 min).
    Conclusions: LGK Lightning allows to generate improved LGK treatment plans regarding plan quality with reduced BOT compared to manual forward plans. The inter operator variability showed that multiple users with different experiences can generate similar treatment plan quality using LGK Lightning.
    MeSH term(s) Humans ; Meningeal Neoplasms ; Neuroma, Acoustic/radiotherapy ; Neuroma, Acoustic/surgery ; Radiosurgery ; Radiotherapy Planning, Computer-Assisted ; Retrospective Studies
    Language English
    Publishing date 2021-03-08
    Publishing country Italy
    Document type Journal Article
    ZDB-ID 1122650-x
    ISSN 1724-191X ; 1120-1797
    ISSN (online) 1724-191X
    ISSN 1120-1797
    DOI 10.1016/j.ejmp.2021.02.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: A novel surface imaging system for patient positioning and surveillance during radiotherapy. A phantom study and clinical evaluation.

    Stieler, F / Wenz, F / Shi, M / Lohr, F

    Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al

    2013  Volume 189, Issue 11, Page(s) 938–944

    Abstract: Background: The use of optical surface positioning to support or replace X-ray-based image-guided radiotherapy (IGRT) may reduce patient exposure to extra dose. In specifically designed phantom tests, we analyzed the potential of a new scanning device ... ...

    Abstract Background: The use of optical surface positioning to support or replace X-ray-based image-guided radiotherapy (IGRT) may reduce patient exposure to extra dose. In specifically designed phantom tests, we analyzed the potential of a new scanning device preclinically. The system's clinical performance was evaluated in comparison to cone-beam computed tomography (CBCT) in a prospective study.
    Materials and methods: We first evaluated the scanning performance in terms of accuracy and reproducibility using phantom tests. An institutional review board (IRB)-approved clinical evaluation encompassing 224 fractions in 13 patients treated in three different regions (head and neck, thorax, pelvis) was then performed. Patients were first positioned using CBCT and then scanned with the Catalyst(TM) (C-RAD, Uppsala, Sweden) optical system to define the resulting difference vector.
    Results: Individual system settings are necessary for different scanning conditions. Reproducibility tests with phantoms showed a mean difference of 0.25 ± 0.21 cm. Accuracy tests showed a mean difference of less than 0.52 ± 0.41 cm. Considering all patients, clinical data showed residual target position differences between Catalyst(TM) (surface-driven) and CBCT (target-driven) systems within 0.07 ± 0.28 cm/- 0.13 ± 0.40 cm/0.15 ± 0.36 cm/0.11 ± 1.57°/- 0.43 ± 1.68/- 0.10 ± 1.67° (lateral/longitudinal/vertical/rotation/roll/pitch).
    Conclusion: Scanning quality depends on the color and shape of the scanned surface. Upon prospective clinical evaluation, excellent agreement between target- and contour driven positioning was observed. Catalyst(TM) may reduce CBCT scan frequency in patients where tumor location is fixed relative to the surface.
    MeSH term(s) Equipment Design ; Equipment Failure Analysis ; Humans ; Imaging, Three-Dimensional/instrumentation ; Neoplasms/pathology ; Neoplasms/radiotherapy ; Patient Positioning/instrumentation ; Patient Positioning/methods ; Phantoms, Imaging ; Radiotherapy, Conformal/instrumentation ; Radiotherapy, Conformal/methods ; Radiotherapy, Image-Guided/instrumentation ; Radiotherapy, Image-Guided/methods ; Reproducibility of Results ; Sensitivity and Specificity ; Treatment Outcome
    Language English
    Publishing date 2013-09-27
    Publishing country Germany
    Document type Clinical Trial ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 84983-2
    ISSN 1439-099X ; 0179-7158 ; 0039-2073
    ISSN (online) 1439-099X
    ISSN 0179-7158 ; 0039-2073
    DOI 10.1007/s00066-013-0441-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Surface guidance compared with ultrasound-based monitoring and diaphragm position in cone-beam computed tomography during abdominal stereotactic radiotherapy in breath-hold.

    Kaestner, Lena / Streb, Lara / Hetjens, Svetlana / Buergy, Daniel / Sihono, Dwi S K / Fleckenstein, Jens / Kalisch, Iris / Eckl, Miriam / Giordano, Frank A / Lohr, Frank / Stieler, Florian / Boda-Heggemann, Judit

    Physics and imaging in radiation oncology

    2023  Volume 27, Page(s) 100455

    Abstract: Background and purpose: Spirometry induced deep-inspiration-breath-hold (DIBH) reduces intrafractional motion during upper abdominal stereotactic body radiotherapy (SBRT). The aim of this prospective study was to evaluate whether surface scanning (SGRT) ...

    Abstract Background and purpose: Spirometry induced deep-inspiration-breath-hold (DIBH) reduces intrafractional motion during upper abdominal stereotactic body radiotherapy (SBRT). The aim of this prospective study was to evaluate whether surface scanning (SGRT) is an adequate surrogate for monitoring residual internal motion during DIBH. Residual motion detected by SGRT was compared with experimental 4D-ultrasound (US) and an internal motion detection benchmark (diaphragm-dome-position in kV cone-beam computed tomography (CBCT) projections).
    Materials and methods: Intrafractional monitoring was performed with SGRT and US in 460 DIBHs of 12 patients. Residual motion detected by all modalities (SGRT (anterior-posterior (AP)), US (AP, craniocaudal (CC)) and CBCT (CC)) was analyzed. Agreement analysis included Wilcoxon signed rank test, Maloney and Rastogi's test, Pearson's correlation coefficient (PCC) and interclass correlation coefficient (ICC).
    Results: Interquartile range was 0.7 mm (US(AP)), 0.8 mm (US(CC)), 0.9 mm (SGRT) and 0.8 mm (CBCT). SGRT(AP) vs. CBCT(CC) and US(CC) vs. CBCT(CC) showed comparable agreement (PCCs 0.53 and 0.52, ICCs 0.51 and 0.49) with slightly higher precision of CBCT(CC). Most agreement was observed for SGRT(AP) vs. US(AP) with largest PCC (0.61) and ICC (0.60), least agreement for SGRT(AP) vs. US(CC) with smallest PCC (0.44) and ICC (0.42).
    Conclusions: Residual motion detected during spirometry induced DIBH is small. SGRT alone is no sufficient surrogate for residual internal motion in all patients as some high velocity motion could not be detected. Observed patient-specific residual errors may require individualized PTV-margins.
    Language English
    Publishing date 2023-06-05
    Publishing country Netherlands
    Document type Journal Article
    ISSN 2405-6316
    ISSN (online) 2405-6316
    DOI 10.1016/j.phro.2023.100455
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Clinical evaluation of a commercial surface-imaging system for patient positioning in radiotherapy.

    Stieler, F / Wenz, F / Scherrer, D / Bernhardt, M / Lohr, F

    Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al

    2012  Volume 188, Issue 12, Page(s) 1080–1084

    Abstract: Background: Laser scanning-based patient surface positioning and surveillance may complement image-guided radiotherapy (IGRT) as a nonradiation-based approach. We investigated the performance of an optical system compared to standard kilovoltage cone- ... ...

    Abstract Background: Laser scanning-based patient surface positioning and surveillance may complement image-guided radiotherapy (IGRT) as a nonradiation-based approach. We investigated the performance of an optical system compared to standard kilovoltage cone-beam computed tomography (CBCT) and its potential to reduce the number of daily CBCTs.
    Patients and methods: We analyzed the patient positioning of 153 treatment fractions in 21 patients applied to three different treatment regions. Patients were first scanned with CBCT, shifted to the optimal isocenter position, and an optical scan was performed to verify the matching in relation to CBCT.
    Results: For the head-and-neck region, the lateral/longitudinal/vertical/rotational/roll and pitch shift was 0.9 ± 1.8 mm/-2.7 ± 3.8 mm/-0.8 ± 3.6 mm/0.0 ± 1.1°/-0.5 ± 2.1°/0.2 ± 1.6°. For the thorax, the lateral/longitudinal/vertical/roll and pitch shift was -1.2 ± 3.6 mm/0.8 ± 5.1 mm/0.8 ± 4.3 mm/0.6 ± 1.4°/0.1 ± 0.9°/0.3 ± 1.0°. For the pelvis, the respective values were -2.5 ± 4.1 mm/4.6 ± 7.3 mm/-5.1 ± 7.4 mm/0.3 ± 1.1°/-0.5 ± 1.0°/0.3 ± 2.1°. In total, the recorded disagreement was -1.0 ± 3.6 mm/1.0 ± 6.3 mm/-1.8 ± 5.9 mm/0.3 ± 1.2°/-0.3 ± 1.5°/0.2 ± 1.7°.
    Conclusion: This analysis showed good agreement between the optical scanner approach and CBCT. The optical system holds potential to ensure precise patient positioning and reduced CBCT frequency in tumor locations with fixed relation to surface structures.
    MeSH term(s) Cone-Beam Computed Tomography/instrumentation ; Equipment Design ; Female ; Humans ; Lasers ; Male ; Neoplasms/radiotherapy ; Patient Positioning/instrumentation ; Radiotherapy Planning, Computer-Assisted/instrumentation ; Radiotherapy, Image-Guided/instrumentation ; Retrospective Studies ; Supine Position
    Language English
    Publishing date 2012-11-10
    Publishing country Germany
    Document type Comparative Study ; Evaluation Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 84983-2
    ISSN 1439-099X ; 0179-7158 ; 0039-2073
    ISSN (online) 1439-099X
    ISSN 0179-7158 ; 0039-2073
    DOI 10.1007/s00066-012-0244-7
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  9. Article: Motion Management in a Patient With Tracheostomy During Lung Stereotactic Body Radiation Therapy: Breath Hold Is Worth a Try.

    Kaestner, Lena / Abo-Madyan, Yasser / Huber, Lena / Spaniol, Manon / Siebenlist, Kerstin / Sacks, Marie-Kristin / Ehmann, Michael / Stieler, Florian / Clausen, Sven / Lohr, Frank / Fleckenstein, Jens / Boda-Heggemann, Judit

    Advances in radiation oncology

    2022  Volume 7, Issue 3, Page(s) 100895

    Language English
    Publishing date 2022-01-15
    Publishing country United States
    Document type Case Reports
    ISSN 2452-1094
    ISSN 2452-1094
    DOI 10.1016/j.adro.2022.100895
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  10. Article ; Online: Prospective assessment of mask versus frame fixation during Gamma Knife treatment for brain metastases.

    Grimm, Mario A / Köppen, Ulrich / Stieler, Florian / Welzel, Grit / Ruder, Arne Mathias / Polednik, Martin / Wenz, Frederik / Mai, Sabine K / Giordano, Frank A

    Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

    2020  Volume 147, Page(s) 195–199

    Abstract: Purpose: The newest generation of the Leksell Gamma Knife (GK) allows frame based as well as frameless treatment. We here report outcomes of a prospective non-randomized study on mask fixation (MF) versus frame fixation (FF) for GK treatment of brain ... ...

    Abstract Purpose: The newest generation of the Leksell Gamma Knife (GK) allows frame based as well as frameless treatment. We here report outcomes of a prospective non-randomized study on mask fixation (MF) versus frame fixation (FF) for GK treatment of brain metastases.
    Methods: The decision for FF or MF was made on a case-by-case basis. Factors considered were patients' preference, proximity of critical structures, V
    Results: A total of 197 lesions (169 FF and 28 MF) were treated in 76 patients (59 FF and 17 MF). 187 lesions were treated with SRS and 10 with FSRT. Median dose was 22 Gy in both groups and median follow-up was 9.3 months. There was a higher local failure rate (HR: 3.69; 95%CI: 1.13-12.0; p = 0.03) with 11 local failures in the FF and none in the MF cohort. No differences were observed between the groups for OS (median: n.r. vs. 16.9 months; HR:1.00; 95%CI: 0.41-2.46; p = 0.999) and PFS (median: 6.9 vs. 8.4 months; HR: 0.92; 95%CI: 0.47-1.79; p = 0.800). Three cases of radionecrosis occurred with FF but none with MF (p = 0.67).
    Conclusions: Gamma Knife treatment with MF does not result in worse outcome or increased rates of radionecrosis in this non-randomized study.
    MeSH term(s) Brain Neoplasms/radiotherapy ; Brain Neoplasms/surgery ; Follow-Up Studies ; Humans ; Progression-Free Survival ; Prospective Studies ; Radiosurgery/adverse effects ; Retrospective Studies ; Treatment Outcome
    Language English
    Publishing date 2020-05-19
    Publishing country Ireland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 605646-5
    ISSN 1879-0887 ; 0167-8140
    ISSN (online) 1879-0887
    ISSN 0167-8140
    DOI 10.1016/j.radonc.2020.05.011
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