Gabriela Monika Studer

Prof. Dr. Gabriela Monika Studer

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Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 January 2011 in Radiation Oncology
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EPEvangelia Peponi
Evangelia Peponi
CGChristoph Glanzmann
Christoph Glanzmann
BWBettina Willi
Bettina Willi
GHGerhard Huber
Gerhard Huber
GSGabriela Monika Studer
Gabriela Monika Studer
Background: To evaluate the objective and subjective long term swallowing function, and to relate dysphagia to the radiation dose delivered to the critical anatomical structures in head and neck cancer patients treated with intensity modulated radiation therapy (IMRT, +/- chemotherapy), using a midline protection contour (below hyoid, ~level of vertebra 2/3). Methods: 82 patients with stage III/IV squamous cell carcinoma of the larynx, oropharynx, or hypopharynx, who underwent successful definitive (n = 63, mean dose 68.9Gy) or postoperative (n = 19, mean dose 64.2Gy) simultaneous integrated boost (SIB) -IMRT either alone or in combination with chemotherapy (85%) with curative intent between January 2002 and November 2005, were evaluated retrospectively. 13/63 definitively irradiated patients (21%) presented with a total gross tumor volume (tGTV) >70cc (82-173cc; mean 106cc). In all patients, a laryngo-pharyngeal midline sparing contour outside of the PTV was drawn. Dysphagia was graded according subjective patient-reported and objective observer-assessed instruments. All patients were re-assessed 12 months later. Dose distribution to the swallowing structures was calculated. Results: At the re-assessment, 32-month mean post treatment follow-up (range 16-60), grade 3/4 objective toxicity was assessed in 10%. At the 32-month evaluation as well as at the last follow up assessment mean 50 months (16-85) post-treatment, persisting swallowing dysfunction grade 3 was subjectively and objectively observed in 1 patient (1%). The 5-year local control rate of the cohort was 75%; no medial marginal failures were observed. Conclusions: Our results show that sparing the swallowing structures by IMRT seems effective and relatively safe in terms of avoidance of persistent grade 3/4 late dysphagia and local disease control.

1 May 2006 in Strahlentherapie und Onkologie
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GSGabriela Monika Studer
Gabriela Monika Studer
SSStephan Philipp Studer
Stephan Philipp Studer
RZRoger Arthur Zwahlen
Roger Arthur Zwahlen
PHPia Huguenin
Pia Huguenin
KGKlaus Wilhelm Grätz
Klaus Wilhelm Grätz
CGChristoph Glanzmann
Christoph Glanzmann

10 November 2015 in Radiation Oncology
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Journal Article
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JKJerome Krayenbuehl
Jerome Krayenbuehl
INIan Norton
Ian Norton
GSGabriela Monika Studer
Gabriela Monika Studer
MGMatthias Guckenberger
Matthias Guckenberger
This study evaluated an automated inverse treatment planning algorithm, Pinnacle Auto-Planning (AP), and compared automatically generated plans with historical plans in a large cohort of head and neck cancer patients. Fifty consecutive patients treated with volumetric modulated arc therapy (Eclipse, Varian Medical System, Palo Alto, CA) for head and neck were re-planned with AP version 9.10. Only one single cycle of plan optimization using one single template was allowed for AP. The dose to the planning target volumes (PTV’s; 3–4 dose levels), the organs at risk (OAR’s) and the effective working time for planning was evaluated. Additionally, two experienced radiation oncologists blind-reviewed and ranked 10 plans. Dose coverage and dose homogeneity of the PTV were significantly improved with AP, however manually optimized plans showed significantly improved dose conformity. The mean dose to the parotid glands, oral mucosa, swallowing muscles, dorsal neck tissue and maximal dose to the spinal cord were significantly reduced with AP. In 64 % of the plans, the mean dose to any OAR (spinal cord excluded) was reduced by >20 % with AP in comparison to the manually optimized plans. In 12 % of the plans, the manually optimized plans showed reduced doses by >20 % in at least one OAR. The experienced radiation oncologists preferred the AP plan and the clinical plan in 80 and 20 % of the cases, respectively. The average effective working time was 3.8 min ± 1.1 min in comparison to 48.5 min ± 6.0 min using AP compared to the manually optimized plans, respectively. The evaluated automated planning algorithm achieved highly consistent and significantly improved treatment plans with potentially clinically relevant OAR sparing by >20 % in 64 % of the cases. The effective working time was substantially reduced with Auto-Planning.

1 January 2007 in Acta Oncologica
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Journal Article
Open access
GSGabriela Monika Studer
Gabriela Monika Studer
ULU. M. Lütolf
U. M. Lütolf
MEM. El-Bassiouni
M. El-Bassiouni
VRV. Rousson
V. Rousson
CGC. Glanzmann
C. Glanzmann
The UICC classification (TNM) represents the validated standard tool to describe tumor extent and includes prognostic information on the probability of disease control. The American Joint Committee on Cancer (AJCC) stage grouping is based on the evaluation of treatment and outcome. Gross tumor volume (GTV) might be more relevant than pure description (TNM) or stage grouping as prognostic factor for local control in head and neck cancer (HNC). Based on the observation of GTV-correlated outcome in our initial HNC patient cohort treated with IMRT, we tested the hypothesis that the GTV is the most reliable predictive tool in HNC outcome. A GTV based volumetric staging system (VS) was introduced, using two volumetric cut-off values (15 and 70 cm3). VS, TNM, and AJCC stages were assessed and correlated with outcome following primary radiation in 172 HNC patients. Analyses were based on Kaplan-Meier survival curves. VS proved to be superior to the TNM/AJCC in predicting outcome. In addition, VS enabled to stratify high- and low-risk patients in advanced TN stages. GTV represented the most important prognostic indicator in HNC treated with IMRT and is recommended to be considered for therapeutic decisions and estimation of outcome.

12 August 2015 in Strahlentherapie und Onkologie
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Journal Article
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GSGabriela Monika Studer
Gabriela Monika Studer
MBMarius Bredell
Marius Bredell
SSStephan Studer
Stephan Studer
GHGerhard Huber
Gerhard Huber
CGChristoph Glanzmann
Christoph Glanzmann
Background The risk for osteoradionecrosis (ORN) of the mandible is positively related to bone volume exposed to > ~ 60 Gy. We hypothesized that in combined treatment, surgery may also be a risk factor. Patients and methods The impact of mandibular surgery on ORN in locally disease-free IMRT cohorts was retrospectively analyzed. Results Between October 2002 and October 2013, 531 of 715 patients with oral cavity cancer (OCC), mesopharyngeal cancer (MC), or salivary gland tumor were treated with the mandible bone exposed to ~ > 60 Gy (mean follow-up, 38 months; 7–143 months). Of the 531 patients, 36 developed ORN (7 %; 1.5 % with grade 3–4). The ORN rate in definitive IMRT MC (16/227) and in postoperative IMRT OCC patients with no mandibular surgery (3/46) was 7 % each; in OCC patients with mandibular surgery the rate was 29 % (15/60, p = 0.002). Marginal or periosteal bone resection was found to be a high risk factor (39 %, vs. 7 % followed by segmental or no resection, p < 0.0001). Conclusion Marginal or periosteal bone resection of the mandible was identified as the highest ORN risk factor in our IMRT cohort.

1 April 2004 in Strahlentherapie und Onkologie
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GSGabriela Monika Studer
Gabriela Monika Studer
KGKlaus W. Grätz
Klaus W. Grätz
CGChristoph Glanzmann
Christoph Glanzmann