A5000926307- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Radiomics and Machine Learning in Medical Imaging
- Lung Cancer Diagnosis and Treatment
- Advanced MRI Techniques and Applications
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Radiation Effects and Dosimetry
- Lipid metabolism and biosynthesis
- Radiation Effects in Electronics
- Cancer, Lipids, and Metabolism
- Management of metastatic bone disease
- Cancer, Hypoxia, and Metabolism
- Electron and X-Ray Spectroscopy Techniques
- Mitochondrial Function and Pathology
- Solar Radiation and Photovoltaics
- Dark Matter and Cosmic Phenomena
- Hepatocellular Carcinoma Treatment and Prognosis
- MRI in cancer diagnosis
Heidelberg University
2016-2025
German Cancer Research Center
2016-2025
Institute for Research in Biomedicine
2024
DKFZ-ZMBH Alliance
2016-2024
Helmholtz Association of German Research Centres
2020
Harvard University
2010-2019
Massachusetts General Hospital
2010-2019
Heidelberger Institut für Radioonkologie
2017-2019
University of Bergen
2019
European Institute of Oncology
2016
Purpose To investigate experimentally, if FLASH irradiation depletes oxygen within water for different radiation types such as photons, protons, and carbon ions. Methods This study presents measurements of the consumption in sealed, 3D‐printed phantoms during with x‐rays, ions at varying dose rates up to 340 Gy/s. The measurement was performed using an optical sensor allowing noninvasive measurements. Results Oxygen only depends on dose, rate, linear energy transfer (LET) irradiation. total...
We present an experimental study of a novel method to verify the range proton therapy beams. Differential cross sections were measured for 15 prompt gamma-ray lines from proton-nuclear interactions with (12)C and (16)O at energies up 150 MeV. These used model discrete emissions along pencil-beams. By fitting detected counts these models, we simultaneously determined beam oxygen carbon concentration irradiated matter. The performance was assessed in two phantoms different elemental...
Treatment delivery with active beam scanning in proton radiation therapy introduces the problem of interplay effects when pencil motion occurs on a similar time scale as intra-fractional tumor motion. In situations where fractionation may not provide enough repetition to blur interplay, repeated or 'repainting' each field several times within fraction has been suggested. The purpose this work was investigate effectiveness different repainting strategies scanning. To assess dosimetric impact...
We present and validate a computed tomography (CT) metal artifact reduction method that is effective for wide spectrum of clinical implant materials. Projections through low-Z implants such as titanium were corrected using novel physics correction algorithm reduces beam hardening errors. In the case high-Z (dental fillings, gold, platinum), projections considered missing regularized iterative reconstruction was performed. Both algorithms combined if multiple materials present. For...
Purpose: The authors describe a novel method of predicting mass density and elemental fractions tissues from dual energy CT (DECT) data for Monte Carlo (MC) based dose planning. Methods: relative electron ϱe effective atomic number Zeff are calculated 71 tabulated tissue compositions. For MC simulations, the is derived via one linear fit in that covers entire range compositions (except lung tissue). Elemental predicted combination. Since particle therapy planning verification especially...
In this work, we present experimental results of a novel prompt gamma-ray detector for proton beam range verification. The detection system features an actively shielded cerium-doped lanthanum(III) bromide scintillator, coupled to digital data acquisition system. was synchronized the cyclotron radio frequency separate signals from later-arriving neutron-induced background. We designed provide high energy resolution and effective reduction background events, enabling discrete proton-induced...
Dual energy computed tomography (DECT) can provide simultaneous estimation of relative electron density ρe and effective atomic number Zeff. The ability to obtain these quantities (ρe, Zeff) has been shown benefit selected radiotherapy applications where tissue characterization is required. conventional analysis method (spectral method) relies on knowledge the CT scanner photon spectra which may be difficult accurately. Furthermore an approximate empirical attenuation correction spectrum...
Abstract In-room imaging is a prerequisite for adaptive proton therapy. The use of onboard cone-beam computed tomography (CBCT) imaging, which routinely acquired patient position verification, can enable daily dose reconstructions and plan adaptation decisions. Image quality deficiencies though, hamper calculation accuracy make corrections CBCTs necessity. This study compared three methods to correct create synthetic CTs that are suitable calculations. CBCTs, planning repeated (rCT) from 33...
Photon dose calculation algorithms (such as the pencil beam and collapsed cone, CC) model attenuation of a primary photon in media other than water, by using pathlength scaling based on relative mass density to water. In this study, we assess if differences electron between water media, with different atomic composition, can influence accuracy conventional calculations algorithms. A comparison is performed an electron‐density method standard mass‐density for (i) tissues present human body...
The conversion of computed tomography (CT) numbers into material composition and mass density data influences the accuracy patient dose calculations in Monte Carlo treatment planning (MCTP). aim our work was to develop a CT scheme by performing stoichiometric calibration. Fourteen dosimetrically equivalent tissue subsets (bins), which ten bone bins, were created. After validating proposed on phantoms, it compared conventional five bin with only one bin. This resulted distributions D 14 5 for...
Interplay between organ (breathing) motion and leaf has been shown in the literature to have a small dosimetric impact for clinical conditions (over 30 fraction treatment). However, previous studies did not consider case of treatment beams made up many few-monitor-unit (MU) segments, where segment delivery time (1-2 s) is order breathing period (3-5 s). In this study we assess if compromises radiotherapy with IMRT segments low number MUs. We (i) how delivered dose varies, from patient...
The measurement of prompt gamma rays emitted from proton-induced nuclear reactions has been proposed as a method to verify in vivo the range clinical proton radiotherapy beam. A good understanding gamma-ray emission during therapy is key develop clinically feasible technique, it can facilitate accurate simulations and uncertainty analysis detector designs. Also, production cross-sections may be incorporated prior knowledge reconstruction measurements. In this work, we performed with main...
Proton, as well other ion, beams applied by electro-magnetic deflection in pencil-beam scanning (PBS) are minimally perturbed and thus can be quantified a priori their fundamental interactions medium. This quantification permits an optimal reduction of characterizing measurements on particular PBS delivery system. The combination will then suffice to fully describe the physical necessary for treatment planning purposes. We consider, proton beams, these derive 'Golden' beam data set. Golden...
Breast cancer is the most frequent in women worldwide and late diagnosis often adversely affects prognosis of disease. Radiotherapy commonly used to treat breast cancer, reducing risk recurrence after surgery. However, eradication radioresistant cells, including stem remains main challenge radiotherapy. Recently, lipid droplets (LDs) have been proposed as functional markers also being involved increased cell tumorigenicity. LD biogenesis a multistep process requiring various enzymes,...
The Monte Carlo method provides the most accurate dose calculations on a patient computed tomography (CT) geometry. increase in accuracy is, at least part, due to fact that instead of treating human tissues as water various densities analytical algorithms, allows be characterized by elemental composition and mass density, hence consideration all relevant electromagnetic nuclear interactions. On other hand, algorithm convert CT Hounsfield numbers tissue materials for calculation introduces...