A5006343705- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Radiation Detection and Scintillator Technologies
- Radiation Dose and Imaging
- Nuclear Physics and Applications
- Advanced X-ray and CT Imaging
- Radiation Effects in Electronics
- Medical Imaging Techniques and Applications
- Nuclear reactor physics and engineering
- Radiation Effects and Dosimetry
- Breast Cancer Treatment Studies
- Graphite, nuclear technology, radiation studies
- Chalcogenide Semiconductor Thin Films
- Boron Compounds in Chemistry
- Advances in Oncology and Radiotherapy
- Cancer Treatment and Pharmacology
- Nuclear Materials and Properties
- Radioactive Decay and Measurement Techniques
- Laser-Plasma Interactions and Diagnostics
- Digital Radiography and Breast Imaging
- Quantum Dots Synthesis And Properties
- ZnO doping and properties
- Particle Detector Development and Performance
- Effects of Radiation Exposure
- Lung Cancer Diagnosis and Treatment
Philipps University of Marburg
2011-2024
Technische Hochschule Mittelhessen
2015-2024
Universitätsklinikum Gießen und Marburg
2015-2024
University Medical Center
2015-2023
Frankfurt Institute for Advanced Studies
2017-2021
University of Applied Sciences Potsdam
2020
Goethe Institut
2019
Goethe University Frankfurt
2018-2019
GSI Helmholtz Centre for Heavy Ion Research
2017-2019
Universitätsklinik für Strahlentherapie
2017
This article presents the implementation of several variance reduction techniques that dramatically improve simulation efficiency ion chamber dose and perturbation factor calculations. The cavity user code for EGSnrc Monte Carlo system is extended by photon cross‐section enhancement (XCSE), an intermediate phase‐space storage (IPSS) technique, a correlated sampling (CS) scheme. XCSE increases density interaction sites inside in vicinity results—in combination with Russian Roulette game...
This paper presents a detailed investigation into the calculation of perturbation and beam quality correction factors for ionization chambers in high-energy photon beams with use Monte Carlo simulations. For model NE2571 Farmer-type chamber, all separate as found current dosimetry protocols were calculated fixed order compared to currently available data. Furthermore, PTW31010 thimble chamber used calculate factor kQ. The calculations kQ showed good agreement published values AAPM TG-51 IAEA...
Biological optimization for treatment planning in carbon ion therapy is currently based on the first version of local effect model (LEM I). Further developments implemented latest IV) allowed to predict more accurately Relative Effectiveness (RBE) in-vitro. The main goal this study compare LEM IV against I under treatment-like conditions idealized target geometries. Therefore, physical dose distributions resulting from biological with were used recalculate RBE-weighted distribution IV. Input...
The application of small photon fields in modern radiotherapy requires the determination total scatter factors Scp or field Ω(f(clin), f(msr))(Q(clin), Q(msr)) with high precision. Both quantities require knowledge field-size-dependent and detector-dependent correction factor k(f(clin), Q(msr)). aim this study is for different types detectors a clinical 6 MV beam Siemens KD linear accelerator. EGSnrc Monte Carlo code was used to calculate dose water determine as well mentioned square sizes....
Different ion types offer different physical and biological advantages for therapeutic applications. The purpose of this work is to assess the most commonly used ions in particle therapy, i.e., carbon ((12)C), helium ((4)He), protons ((1)H) treatment scenarios.A planning analysis based on idealized target geometries was performed using software TRiP98. For prediction relative effectiveness (RBE) that required optimization local effect model (LEM IV) used. To compare three types,...
The purpose of this work was to design and manufacture a 3D range-modulator for scanned particle therapy. modulator is intended create highly conformal dose distribution with only one fixed energy, simultaneously reducing considerably the treatment time. As proof concept, developed spherical target volume diameter 5 cm, placed at depth 25 cm in water phantom. It consists large number thin pins well-defined shape different lengths modulate necessary shift Bragg peak. manufactured rapid...
Modern Monte Carlo codes allow for the calculation of ion chamber specific beam quality correction factors kQ, which are needed dosimetry in radiotherapy. While statistical (type A) uncertainties calculated data can be minimized sufficiently, influence systematic B) is mostly unknown. This study presents an investigation Carlo-based kQ values a NE2571 thimble chamber, with EGSnrc system. Starting some general on transport parameter settings, geometry and source variations studied....
Proton radiotherapy is rapidly becoming a standard treatment option for cancer. However, even though experimental data show an increase of the relative biological effectiveness (RBE) with depth, particularly at distal end field, generic RBE 1.1 currently used in proton radiotherapy. This discrepancy might affect effective penetration depth beam and thus dose to surrounding tissue organs risk. The purpose this study was analyze impact dependent protons on range comparison based 1.1.Factors...
The IAEA is currently coordinating a multi-year project to update the TRS-398 Code of Practice for dosimetry external beam radiotherapy based on standards absorbed dose water. One major aspect determination new quality correction factors, k Q , megavoltage photon beams consistent with developments in and technology since publication 2000. Specifically, all values must be on, or with, key data ICRU Report 90. Data sets obtained from Monte Carlo (MC) calculations by advanced users measurements...
The Marburg Ion-Beam Therapy Center (MIT) is one of two particle therapy centers in Germany that enables the treatment patients with both protons and carbon ions. facility was build by Siemens Healthineers only worldwide built (Marburg, Shanghai, China). present report provides an overview technical clinical operations as well research activities at MIT.
Tumor motion is a major challenge for scanned ion-beam therapy. In the case of lung tumors, strong under- and overdosage can be induced due to high density gradients between tumor- bone tissues compared tissues. This work proposes non-invasive concept 4D monitoring in carbon ion beam therapy, by detecting charged fragments. The method implements CMOS particle trackers that are used reconstruct fragment vertices, which define emission points nuclear interactions primary ions patient A 3D...
Current dosimetry protocols (AAPM, IAEA, IPEM, DIN) recommend parallel-plate ionization chambers for dose measurements in clinical electron beams. This study presents detailed Monte Carlo simulations of beam quality correction factors four different types chambers: NACP-02, Markus, Advanced Markus and Roos. These differ constructive details which should have notable impact on the resulting perturbation corrections, hence corrections. The results reveal deviations to recommended corrections...
Monte Carlo (MC) calculations are a fundamental tool for the investigation of ionization chambers (ICs) in radiation fields, and scope IC reference dosimetry. Geant4, as used toolkit TOPAS, is major general purpose code, generally suitable investigating ICs primary proton beams. To provide reliable results, impact parameter settings limitations underlying condensed history (CH) algorithm need to be known. A Fano cavity test was implemented Geant4 (10.03.p1) protons, based on existing version...
The purpose of this work is to analyze whether the Monte Carlo codes penh, fluka, and geant4/topas are suitable calculate absorbed doses
Precise and reliable monitoring of the particle rate is great importance at accelerator facilities worldwide. In this article we describe standard beam monitor calibration currently employed multi-purpose experimental sites Cave A M GSI, where intense highly energetic ion beams are routinely used for a wide variety experiments. An absolute dose-to-water measurement performed with an air-filled ionization chamber transferred into per primary particle. This necessary raster scanning system to...
Ultrahigh dose-rate radiation (UHDR) produces less hydrogen peroxide (H
Current dosimetry protocols (AAPM, IAEA, DIN) recommend the use of parallel-plate ionization chambers for measurement absorbed dose-to-water in clinical electron beams. For well-guarded plane-parallel chambers, it is assumed that perturbation correction pQ unity all energies. In this study, we present detailed Monte Carlo simulations with EGSnrc code widely used Roos chamber which is, besides other types, recommended protocols. We have calculated corrections pcav and pwall a wide range...
In 2016 the ICRU published a new report dealing with key data for ionizing radiation dosimetry (ICRU Report 90). New recommendations have been made mean excitation energies I air, graphite and liquid water as well density to use when evaluating effect. addition, 90 discusses renormalized photoelectric cross sections, but refuses give recommendation on of renormalization factors. However, Consultative Committee Ionizing Radiation recommends photoeffect sections. Goal present work is evaluate...
Measured cross sections for the production of PET isotopes [Formula: see text], text] and from carbon oxygen targets induced by protons (40-220 text]) ions (65-430 are presented. These data were obtained via activation measurements irradiated graphite beryllium oxide using a set three scintillators coupled coincidence logic. The measured relevant particle range verification method where accurate predictions emitter distribution produced therapeutic beams in patient tissue required. presented...
Abstract To provide Monte Carlo calculated beam quality correction factors ( k Q ) for monoenergetic proton beams using , a toolkit based on the code . simulations of six plane-parallel and four cylindrical ionization chambers were carried out. The latest ICRU 90 recommendations key data ionizing-radiation dosimetry used to calculate electronic stopping powers select mean energy necessary create an ion pair in air ). 60 Co spectrum at depth 5 g cm −2 f ratios as well entrance region with...