A5037378405- Radiation Therapy and Dosimetry
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- Advanced Radiotherapy Techniques
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Radiation Dose and Imaging
- Radiation Effects in Electronics
- Radiomics and Machine Learning in Medical Imaging
- MRI in cancer diagnosis
- Nuclear reactor physics and engineering
- Advanced MRI Techniques and Applications
- Atomic and Molecular Physics
- Medical Image Segmentation Techniques
- Gamma-ray bursts and supernovae
- Lung Cancer Diagnosis and Treatment
- X-ray Spectroscopy and Fluorescence Analysis
- Economic Theory and Institutions
- Real-time simulation and control systems
- Radiation Effects and Dosimetry
- Aerospace and Aviation Technology
- Electron Spin Resonance Studies
- Lanthanide and Transition Metal Complexes
- Radiation Shielding Materials Analysis
- Advanced Sensor Technologies Research
Gradient (United States)
2020
Software (Spain)
2020
Aarhus University Hospital
2011-2019
Inserm
2018
Laboratoire de Traitement de l'Information Médicale
2018
Université de Bretagne Occidentale
2018
San Raffaele University of Rome
2017
Capital Region of Denmark
2016
Aarhus University
2010-2015
Harvard University
2012-2015
To demonstrate a proof-of-concept for fast cone-beam CT (CBCT) intensity correction in projection space by the use of deep learning.The CBCT scans and corresponding projections were acquired from 30 prostate cancer patients. Reference shading was performed using validated method (CBCT cor ), which estimates scatter other low-frequency deviations measured on basis prior image obtained warping planning to CBCT. A convolutional neural network (ScatterNet) designed, consisting an attenuation...
Purpose This work aims at investigating intensity corrected cone‐beam x‐ray computed tomography (CBCT) images for accurate dose calculation in adaptive modulated proton therapy (IMPT) prostate and head neck (H&N) cancer. A deformable image registration (DIR)‐based method a scatter correction approach using the data obtained from DIR as prior are characterized compared on basis of same clinical patient cohort first time. Methods Planning CT (pCT) daily CBCT (reconstructed measured...
Purpose This work proposes the ISMRM Raw Data format as a common MR raw data format, which promotes algorithm and sharing. Methods A file consisting of flexible header tagged frames k‐space was designed. Application Programming Interfaces were implemented in C/C++, MATLAB, Python. Converters for Bruker, General Electric, Philips, Siemens proprietary formats C++. collected using magnetic resonance imaging scanners from four vendors, converted to reconstructed software three programming...
Image intensity correction is crucial to enable cone beam computed tomography (CBCT) based radiotherapy dose calculations. This study evaluated three different deep learning methods using a U-shaped convolutional neural network architecture (Unet) in terms of their photon and proton calculation accuracy.
Dual energy CT (DECT) has been shown, in theoretical and phantom studies, to improve the stopping power ratio (SPR) determination used for proton treatment planning compared use of single (SECT). However, it not shown that this also extends organic tissues. The purpose study was therefore investigate accuracy SPR estimation fresh pork beef tissue samples as surrogates human reference SPRs fourteen samples, which included fat, muscle femur bone, were measured using pencil beams. subsequently...
Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties are currently largest contributor to employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) CT (in development) have both been proposed as methods obtaining patient maps. The purpose of this work was assess accuracy using dual scans phantoms establish reference levels.Material methods. A calibration phantom an abdomen cross section...
Purpose In this study the authors present a new method for estimation of proton stopping power ratios (SPRs) using dual energy CT (DECT), which is robust toward noise. The propose parametrization SPR based directly on numbers in DECT image set, whereby intermediate steps estimating relative electron density, ρ e , and mean excitation energy, I are avoided. Methods proposed purely empirical fit theoretical values list 34 reference human tissues. To investigate made with performed calibration...
Introduction: The recent developments of magnetic resonance (MR) based adaptive strategies for photon and, potentially proton therapy, require a fast and reliable conversion MR images to X-ray computed tomography (CT) values. CT values are needed dose calculation. improvement results employing 3D deep learning approach is evaluated.Material methods: A database 89 T1-weighted head scans with about 100 slices each, including rigidly registered CTs, was created. Twenty-eight validation patients...
Purpose Our aim was to assess a novel 13 C radial fast spin echo golden ratio single shot method for interrogating early renal changes in the diabetic kidney, using hyperpolarized (HP) [ C, 15 N 2 ]urea as T relaxation based contrast bio‐probe. Methods A HP MR experiment conducted group of streptozotocin type‐1 rat model and age matched controls. Results significantly different time ( P = 0.004) found kidney (0.49 ± 0.03 s) compared with controls (0.64 0.02 secondly, strong correlation...
The relative stopping power (RSP) uncertainty is the largest contributor to range in proton therapy. purpose of this work was develop a systematic method that yields accurate and patient-specific RSPs by combining (1) pre-treatment x-ray CT (2) daily radiography patient. formulated as penalized least squares optimization problem (argmin([Formula: see text])). parameter A represents cumulative path-length crossed each material, separated thresholding on HU. material (water equivalent...
The SHIELD-HIT Monte Carlo transport code has been widely used in particle therapy, but previously shown some discrepancies, when compared with experimental data. In this work, the inelastic nuclear cross sections of are calibrated to data for carbon ions. addition, models fragmentation were adjusted experiments, partial charge-changing section ions water. Comparison yield experiments and neon primaries made validation. For primaries, excellent agreement between simulation experiment was...
The importance of nuclear interactions for ion therapy arises from the influence particle spectrum on, first, radiobiology and therefore also on treatment planning, second, accuracy measuring dose and, third, delivered distribution. This study tries to determine qualitative as well quantitative modeling inelastic therapy. Thereby, three key disciplines are investigated, namely delivery, assessment radiobiology. In order perform a analysis, relative comparison between six different...
Purpose: Stopping-power data enter at a number of different places in particle therapy and their uncertainties have direct impact on the accuracy therapy, e.g., treatment planning. Furthermore, for clinical quality assurance, beam stopping-power ratios (STPR) to be known accurately dosimetry.Methods: An open-source computer library called libdEdx (library energy loss per unit path length, dE/dx, calculations) is developed, providing from tables programs as well formula comprising large list...
Purpose: Accurately predicting the range of radiotherapy ions in vivo is important for precise delivery dose particle therapy. Range uncertainty currently single largest contribution to margins used planning and leads a higher normal tissue. The use ion CT has been proposed as method improve thereby reduce tissue patient. A wide variety have studied this purpose, but no studies evaluate image quality obtained with different consistent manner. However, imaging doses concern which may limit...
Purpose: The Monte Carlo (MC) code SHIELD-HIT simulates the transport of ions through matter. Since SHIELD-HIT08 we added numerous features that improves speed, usability and underlying physics thereby user experience. "-A" fork also aims to attach a heavy ion dose optimization algorithm provide MC-optimized treatment plans include radiobiology.
Proton computed tomography (CT) has been demonstrated as a promising image modality in particle therapy planning. It can reduce errors range calculations and consequently improve dose calculations. Obtaining high imaging resolution traditionally required computationally expensive iterative reconstruction techniques to account for the multiple scattering of protons. Recently, direct have developed, but these require higher than methods. No previous work compared quality In this article, we...
We present a new method for reconstruction of 4-D cone beam computed tomography from an undersampled set X-ray projections. The novelty the proposed lies in utilizing optical flow based registration to facilitate that each temporal phase is reconstructed full acquired thus exhibits limited aliasing despite significant intra-phase undersampling. fully self-contained. Initially approximate volume and inter-phase hereon. A subsequent pass integrates estimation cost function formulation which...
Background and PurposeSeveral strategies for estimating stopping power ratio (SPR) from dual-energy CT (DECT) have been proposed to improve accuracy of proton dose calculations. DECT methods can mainly be categorized into projection-based methods, where material decomposition is performed prior image reconstruction, image-based takes place after reconstruction. With the advent photon-counting dual-layer technology, could considered SPR estimation. In this simulation-based study we compared...
In particle therapy, knowledge of the stopping-power ratios (STPRs) ion beam for air and water is necessary accurate ionization chamber dosimetry. Earlier work has investigated STPRs pristine carbon beams, but here we expand calculations to a range ions (1 <= z 18) as well spread out Bragg peaks (SOBPs) provide theoretical in-depth study with special focus on parameter regime relevant therapy. The Monte Carlo transport code SHIELD-HIT used calculate complete particle-fluence spectra which...
Background. In radiation therapy, the principal dosimetric quantity of interest is absorbed dose to water. Therefore, a conversion water required for deposited by ion beams in other media. This particular necessary measurements plastic phantoms increased positioning accuracy, graphite calorimetry being developed as primary standard dosimetry, but also comparison distributions from Monte Carlo simulations with those pencil beam algorithms. Material and methods. phantom material...
Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations particle therapy. However, finite range of about 33 cm water most commercial proton therapy systems limits sites that can be scanned from full 360° rotation. In this paper authors propose method to overcome problem using dual reconstruction (DMR) combining data with cone‐beam x‐ray prior. Methods: A Catphan 600 phantom was cone beam CT scanner. digital...
Purpose: The SHIELD-HIT Monte Carlo particle transport code has previously been used to study a wide range of problems for heavy-ion treatment and benchmarked extensively against other codes experimental data. Here, an improved version is developed concentrating on three objectives, namely: Enhanced functionality, efficiency, modification employed physical models.Methodological developments: (currently at '10A') now equipped with independent detector geometry, ripple filter implementations,...