A5033862514- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Radiation Detection and Scintillator Technologies
- Radiation Dose and Imaging
- Radiomics and Machine Learning in Medical Imaging
- Radiation Effects and Dosimetry
- Head and Neck Cancer Studies
- Lung Cancer Diagnosis and Treatment
- Glioma Diagnosis and Treatment
- Meningioma and schwannoma management
- Advances in Oncology and Radiotherapy
- Nuclear Physics and Applications
- Advanced MRI Techniques and Applications
- Brain Tumor Detection and Classification
- Prostate Cancer Treatment and Research
- Vestibular and auditory disorders
- Radiation Effects in Electronics
- Digital Radiography and Breast Imaging
- Prostate Cancer Diagnosis and Treatment
- Vascular Malformations Diagnosis and Treatment
- Health Systems, Economic Evaluations, Quality of Life
- Management of metastatic bone disease
- Brain Metastases and Treatment
University Hospital of Bern
2016-2025
University of Bern
2016-2025
Medical University of Vienna
2021-2022
Radiation Oncology Associates
2021
Università Cattolica del Sacro Cuore
2016
University College London
2016
The Netherlands Cancer Institute
2016
Université Laval
2013
Scanco Medical (Switzerland)
2012
University of Zurich
1978-2004
Abstract Background Automated brain tumor segmentation methods are computational algorithms that yield delineation from, in this case, multimodal magnetic resonance imaging (MRI). We present an automated method and its results for resection cavity (RC) glioblastoma multiforme (GBM) patients using deep learning (DL) technologies. Methods Post-operative, T1w with without contrast, T2w fluid attenuated inversion recovery MRI studies of 30 GBM were included. Three radiation oncologists manually...
We compared dynamic trajectory radiotherapy (DTRT) to state-of-the-art volumetric modulated arc therapy (VMAT) for 46 head and neck cancer cases. DTRT had lower dose salivary glands swallowing structure, resulting in predicted xerostomia dysphagia VMAT. is deliverable on C-arm linacs with high dosimetric accuracy.
A multiple source model (MSM) for the 6 MV beam of a Varian Clinac 2300 C/D was developed by simulating radiation transport through accelerator head set square fields using GEANT Monte Carlo (MC) code. The corresponding phase space (PS) data enabled characterization 12 sources representing main components defining system. By parametrizing characteristics and evaluating dependence parameters on field size, it possible to extend validity arbitrary rectangular which include central 3×3 cm2...
Currently photon Monte Carlo treatment planning (MCTP) for a patient stored in the database of system (TPS) can usually only be performed using cumbersome multi-step procedure where many user interactions are needed. This means automation is needed usage clinical routine. In addition, because long computing time MCTP, optimization MC calculations essential. For these purposes new graphical interface (GUI)-based environment has been developed resulting very flexible framework. By this...
Purpose: The aim of this work is to evaluate the geometric accuracy a prerelease version new six degrees freedom (6DoF) couch. Additionally, quality assurance method for 6DoF couches proposed. Methods: main principle performance tests was request known shift couch and compare requested with actually applied by independently measuring using different methods (graph paper, laser, inclinometer, imaging system). each axes tested separately as well in combination other axes. Functional cases...
Although volumetric modulated arc therapy (VMAT) is a well-accepted treatment technique in radiotherapy using coplanar delivery approach, VMAT might be further improved by including dynamic table and collimator rotations leading to trajectory (DTRT). In this work, an optimization procedure for DTRT was developed the potential benefit of investigated different sites.
The aim of this work is to develop and investigate an inverse treatment planning process (TPP) for mixed beam radiotherapy (MBRT) capable performing simultaneous optimization photon electron apertures.
Abstract Background To determine the outcome and patterns of failure in oral cavity cancer (OCC) patients after postoperative intensity modulated radiotherapy (IMRT) with concomitant systemic therapy. Methods All locally advanced (AJCC stage III/IV) or high-risk OCC II) who underwent IMRT at our institution between December 2006 July 2010 were retrospectively analyzed. The primary endpoint was locoregional recurrence-free survival (LRRFS). Secondary endpoints included distant metastasis-free...
To determine the 5-year outcome after high-dose-rate brachytherapy (HDR-BT) as a monotherapy.Between 10/2003 and 06/2006, 36 patients with low (28) intermediate (8) risk prostate cancer were treated by HDR-BT monotherapy. All received one implant 4 fractions of 9.5 Gy within 48 hours for total prescribed dose (PD) 38 Gy. Five concomitant androgen deprivation therapy (ADT). Toxicity was scored according to common terminology criteria adverse events from National Cancer Institute (CTCAE)...
Phase-sensitive X-ray imaging shows a high sensitivity towards electron density variations, making it well suited for of soft tissue matter. However, there are still open questions about the details image formation process. Here, framework numerical simulations phase-sensitive is presented, which takes both particle- and wave-like properties X-rays into consideration. A split approach presented where we combine Monte Carlo method (MC) based sample part with wave optics simulation propagation...
The electron Monte Carlo (eMC) dose calculation algorithm available in the Eclipse treatment planning system (Varian Medical Systems) is based on macro MC method and uses a beam model applicable to Varian linear accelerators. This leads limitations accuracy if eMC applied non-Varian machines. In this work generalized also allow accurate calculations for beams from Elekta Siemens First, changes made previous study use low energies of accelerators are applied. Then, developed using main source...
Purpose The purpose of this study was to develop a treatment technique for dynamic mixed beam radiotherapy ( DYMBER ) utilizing increased degrees freedom (DoF) conventional unit including different particle types (photons and electrons), intensity energy modulation gantry, table, collimator rotations. Methods A planning process has been developed create plans combining photon trajectories DT s) step shoot electron apertures collimated with the multileaf pMLC ). gantry‐table path is...
Fully automatic medical image segmentation has been a long pursuit in radiotherapy (RT). Recent developments involving deep learning show promising results yielding consistent and time efficient contours. In order to train validate these systems, several geometric based metrics, such as Dice Similarity Coefficient (DSC), Hausdorff, other related metrics are currently the standard automated challenges. However, relevance of RT is questionable. The quality needs reflect clinical relevant...
Non-coplanar radiotherapy treatment techniques on C-arm linear accelerators have the potential to reduce dose organs-at-risk in comparison with coplanar techniques. Accurately predicting possible collisions between gantry, table and patient during planning is needed ensure safety. We offer a freely available collision prediction tool using Blender, free open-source 3D computer graphics software toolset. A geometric model of accelerator including library models created inside Blender. Based...
Objective.The computational effort to perform beamlet calculation, plan optimization and final dose calculation of a treatment planning process (TPP) generating intensity modulated plans is enormous, especially if Monte Carlo (MC) simulations are used for calculation. The goal this work improve the efficiency fully MC based TPP static dynamic photon, electron mixed photon-electron techniques by implementing multiple methods studying influence their parameters.Approach.A framework implemented...
To improve organ at risk (OAR) sparing, dynamic trajectory radiotherapy (DTRT) extends VMAT by table and collimator rotation during beam-on. However, comprehensive investigations regarding the impact of gantry-table (GT) gradient on DTRT plan quality have not been conducted.To investigate a user-defined GT plans in terms dosimetric quality, robustness, deliverability, delivery time.The trajectories are described gantry-collimator paths. The path is determined minimizing overlap OARs with...
Abstract Background To report acute and late toxicity in prostate cancer patients treated by dose escalated intensity-modulated radiation therapy (IMRT) organ tracking. Methods From 06/2004 to 12/2005 39 men were 80 Gy IMRT along with Median age was 69 years, risk of recurrence low 18%, intermediate 21% high 61% patients. Hormone (HT) received 74% Toxicity scored according the CTC scale version 3.0. follow-up (FU) 29 months. Results Acute maximal grade 2 gastrointestinal (GI) 3% 8%, GI...
Purpose: Recently, the new high definition multileaf collimator (HD120 MLC) was commercialized by Varian Medical Systems providing resolution in center section of treatment field. The aim this work is to investigate characteristics HD120 MLC using Monte Carlo (MC) methods. Methods: Based on information manufacturer, implemented into already existing Swiss MC Plan (SMCP). implementation has been configured adjusting physical density and air gap between adjacent leaves order match transmission...
Purpose: Modulated electron radiotherapy (MERT) promises sparing of organs at risk for certain tumor sites. Any implementation MERT treatment planning requires an accurate beam model. The aim this work is the development a model which reconstructs fields shaped using Millennium photon multileaf collimator (MLC) (Varian Medical Systems, Inc., Palo Alto, CA) Varian linear accelerator (linac). Methods: This divided into analytical part (two and two sources) Monte Carlo (MC) transport through...