A5056621054- Radiation Therapy and Dosimetry
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Radiation Detection and Scintillator Technologies
- Advanced Radiotherapy Techniques
- Laser-induced spectroscopy and plasma
- Medical Imaging Techniques and Applications
- Laser-Matter Interactions and Applications
- Gamma-ray bursts and supernovae
- Advanced X-ray and CT Imaging
- Astronomy and Astrophysical Research
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- Radiation Effects and Dosimetry
- Advanced X-ray Imaging Techniques
- Photocathodes and Microchannel Plates
- Electron and X-Ray Spectroscopy Techniques
- Radiation Dose and Imaging
- Photoacoustic and Ultrasonic Imaging
- Space Technology and Applications
- Atomic and Subatomic Physics Research
- Stellar, planetary, and galactic studies
- Radiation Effects in Electronics
- Advanced Optical Sensing Technologies
- Radioactive Decay and Measurement Techniques
Ludwig-Maximilians-Universität München
2015-2025
MSB Medical School Berlin
2023
LMU Klinikum
2016-2017
Max Planck Institute for Astrophysics
2013
Medium-resolution J-band spectroscopy of individual red supergiant stars is a promising tool to investigate the chemical composition young stellar population in star-forming galaxies. As continuation recent work on iron and titanium, detailed non-LTE (NLTE) calculations are presented influence NLTE formation silicon lines spectra supergiants. Substantial effects found resulting significantly stronger absorption neutral NLTE. consequence, abundances determined smaller than local thermodynamic...
Abstract Orthotopic tumor models in pre-clinical translational research are becoming increasingly popular, raising the demands on accurate localization prior to irradiation. This task remains challenging both X-ray and proton computed tomography (xCT pCT, respectively), due limited contrast of tissue compared surrounding tissue. We investigate feasibility gadolinium oxide nanoparticles as multimodal enhancement agent for imaging modalities.
We performed radiographies at experimental...
The development from single shot basic laser plasma interaction research toward experiments in which repetition rated laser-driven ion sources can be applied requires technological improvements. For example, the case of radio-biological experiments, irradiation duration and reproducible controlled conditions are important for performing studies with a large number samples. We present advancements recent years at ATLAS 300 Garching near Munich since our last radiation biology experiment....
The Bragg peak located at the end of ion beam range is one main advantages therapy compared to X-Ray radiotherapy. However, verifying exact position within patient online a major challenge. goal this work was achieve submillimeter proton verification for pulsed beams an energy up 220 MeV using ionoacoustics clinically relevant dose deposition typically 2 Gy per fraction by i) optimal characteristics ionoacoustic signal generation and ii) improved detection correlating with simulated filter...
Background: Precision small animal radiotherapy research is a young emerging field aiming to provide new experimental insights into tumor and normal tissue models in different microenvironments, unravel complex mechanisms of radiation damage target non-target tissues assess efficacy novel therapeutic strategies. For photon therapy, modern platforms have been developed over the last years are meanwhile commercially available. Conversely, for proton which holds potential an even superior...
Due to the low-dose envelope of scanned proton beams, dose output depends on size irradiated field or volume. While this dependence has already been extensively investigated by measurements and Monte Carlo (MC) simulations for single pencil beams monoenergetic fields, reports relevance effect analytical calculation models are limited. Previous studies topic only exist specific beamline designs. However, amount large-angle scattered primary long-range secondary particles thus can considerably...
Abstract The shape of a wave carries all information about the spatial and temporal structure its source, given that medium properties are known. Most modern imaging methods seek to utilize this nature waves originating from Huygens’ principle. We discuss retrieval complete kinetic energy distribution acoustic trace is recorded when short ion bunch deposits in water. This novel method, which we refer as Ion-Bunch Energy Acoustic Tracing (I-BEAT), refinement ionoacoustic approach. With...
The sharp spatial and temporal dose gradients of pulsed ion beams result in an acoustic emission (ionoacoustics), which can be used to reconstruct the distribution from measurements at different positions. accuracy range verification ionoacoustic images measured with ultrasound linear array configuration is investigated both theoretically experimentally for monoenergetic proton energies relevant pre-clinical studies (20 22 MeV). influence sensor arrangement (length up 4 cm number elements 5...
As one of the latest developments in X-ray computed tomography (CT), photon-counting technology allows spectral detection, demonstrating considerable advantages as compared to conventional CT. In this study, we investigated use a first-generation clinical (PCCT) scanner and estimated proton relative (to water) stopping power (RSP) tissue-equivalent materials from virtual monoenergetic reconstructions provided by scanner. A set calibration evaluation inserts were scanned at 120 kVp. Maps...
Proton computed tomography (pCT) promises to reduce or even eliminate range uncertainties inherent in the conversion of Hounsfield units into relative stopping power (RSP) for proton therapy treatment planning. This is particular interest irradiation studies animal models due high precision required and tissue properties.
Abstract The characteristic depth dose deposition of ion beams, with a maximum at the end their range (Bragg peak) allows for local treatment delivery, resulting in better sparing adjacent healthy tissues compared to other forms external beam radiotherapy treatments. However, optimal clinical exploitation favorable ballistic is hampered by uncertainties vivo Bragg peak position. Ionoacoustics based on detection thermoacoustic pressure waves induced properly pulsed (e.g., produced modern...
Spectroscopy-based photon-counting detector systems, Medipix, have many applications in medicine. Medipix detectors benefit from providing energy information as well high spatial resolution. In this article, a review of technology applied to medicine and imaging techniques are presented. The has been used develop quality assurance (QA) measurement devices radiation-based treatments. A gamma camera system for radiotherapy developed measure dose delivered prostate treatments real-time....
The purpose of this work was to evaluate the ability single and dual energy computed tomography (SECT, DECT) estimate tissue composition density for usage in Monte Carlo (MC) simulations irradiation induced β + activity distributions. This done assess impact on positron emission (PET) range verification proton therapy. A DECT-based brain segmentation method developed white matter (WM), grey (GM) cerebrospinal fluid (CSF). elemental reference tissues assigned closest CT numbers DECT space...
A novel irradiation platform for preclinical proton therapy studies foresees imaging accurate setup and treatment planning. Imaging at modern synchrocyclotron-based centers with high instantaneous particle flux is possible an integration mode setup. The aim of this work to determine object’s water-equivalent thickness (WET) a commercially available large-area CMOS sensor. Image contrast achieved by recording the energy deposition in detector pixels several incoming beam energies (here,...
Purpose: Energy degradation and refocusing of clinical proton beams to energies dimensions relevant for small animal irradiation.Methods: Geant4 Monte Carlo simulations were carried out degrade a 75 MeV beam by graphite 20-60 MeV.A lattice based on permanent-magnet quadrupoles (PMQs) was designed using the beam-optics code elegant, refocus resulting large emittance iso-center.The drift lengths collimator openings further optimized same range while maintaining spot at iso-center, fulfilling...
A common approach for spectrum determination of polyenergetic proton bunches from laser-ion acceleration experiments is based on the time-of-flight (TOF) method. However, spectra obtained using this method are typically given in relative units or estimated some prior assumptions energy distribution accelerated ions. In work, we present a new TOF that allows an absolute reconstruction current signal acquired with sub-nanosecond fast and 10 µm thin silicon detector. The solving linear...
Objective.Image guidance and precise irradiation are fundamental to ensure the reliability of small animal oncology studies. Accurate positioning in-beam monitoring delivered radio-therapeutic treatment necessitate several imaging modalities. In particular context proton therapy with a pulsed beam, information on dose can be retrieved by thermoacoustic waves resulting from brief local energy deposition induced beam (ionoacoustics). The objective this work was fabricate multimodal phantom...
This study investigates the application of broadband capacitive micromachined ultrasonic transducers (CMUT) to ionoacoustics (i.e., thermoacoustic emissions induced by energy deposition ion beam) over a wide frequency range from hundreds kHz few MHz. A water tank was irradiated 20 MeV pulsed proton beam. The and amplitude ionoacoustic waves were modulated adding material before penetrate into change beam its spatial dimensions. measurements performed with 12 MHz CMUT prototype compared ones...
Accurate knowledge of the exact stopping location ions inside patient would allow full exploitation their ballistic properties for treatment. The localized energy deposition a pulsed particle beam induces rapid temperature increase irradiated volume and leads to emission ionoacoustic (IA) waves. Detecting time-of-flight (ToF) IA wave allows inferring information on Bragg peak can henceforth be used forin-vivorange verification. A challenge is poor signal-to-noise ratio at clinically relevant...
Abstract Objectives. The energy deposited in a medium by pulsed proton beam results the emission of thermoacoustic waves, also called ionoacoustics (IA). stopping position (Bragg peak) can be retrieved from time-of-flight analysis (ToF) IA signals acquired at different sensor locations (multilateration). This work aimed to assess robustness multilateration methods beams pre-clinical energies for development small animal irradiator. Approach. accuracy performed using algorithms; namely, time...
Abstract We simulated a doublet of permanent magnet quadrupoles (PMQs) to estimate the sensitivity on positioning precision and its impact spectral properties transported protons. The study guided construction testing focusing setup for laser-accelerated proton bunches with energies between 6 10 MeV. Our results shed light possible applications that may arise from broad input particle spectra.
Laser-accelerated proton bunches with kinetic energies up to several tens of MeV and at repetition rates in the order Hz are nowadays achievable research centres housing high-power laser system. The unique features such ultra-short also arousing interest field radiological biomedical applications. For many these applications, accurate positioning biological target is crucial, raising need for on-site imaging. One convenient option radiography, which can exploit polyenergetic spectrum...