Article
Radiology, Nuclear Medicine & Medical Imaging
Indra J. Das, Paolo Francescon, Jean M. Moran, Anders Ahnesjo, Maria M. Aspradakis, Chee-Wai Cheng, George X. Ding, John D. Fenwick, M. Saiful Huq, Mark Oldham, Chester S. Reft, Otto A. Sauer
Summary: Small-field dosimetry used in advanced treatment technologies faces challenges such as loss of lateral charged particle equilibrium, occlusion of the primary photon source, and limited choices of suitable radiation detectors. The International Atomic Energy Agency (IAEA) and AAPM provide guidelines on dosimetry for small fields, aiming to improve accuracy in dose measurements.
Article
Multidisciplinary Sciences
Sule Parlar, Cem Uzal
Summary: This study investigated the effect of small field output factors obtained with ion chambers of different volumes on intensity-modulated radiotherapy treatment plans. Significant differences were found in output factor values obtained with a 0.65 cc ion chamber in small fields. The greatest difference in point-dose measurements was observed in plans produced using the BM65 beam model.
JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES
(2022)
Article
Engineering, Biomedical
Elena Timakova, Magdalena Bazalova-Carter, Sergei Zavgorodni
Summary: This study evaluated the clinically relevant small field dosimetric properties of a plastic scintillator detector (PSD) with a length and diameter of 1mm and an effective volume of 0.8 mm³. The results showed that the dosimetry system, combined with a scintillation dosimetry system and analysis software, demonstrated good short-term repeatability, dose linearity, and independence of dose rate and angle of irradiation, making it suitable for relative dosimetry measurements for field sizes as small as 0.5 x 0.5 cm².
PHYSICS IN MEDICINE AND BIOLOGY
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
M. Togno, K. P. Nesteruk, R. Schafer, S. Psoroulas, D. Meer, M. Grossmann, J. B. Christensen, E. G. Yukihara, A. J. Lomax, D. C. Weber, S. Safai
Summary: This study aimed to characterize an experimental setup for ultra-high dose rate (UHDR) proton irradiations and address dosimetry challenges in millimetre-small pencil proton beams. Using Faraday cup for proton number measurement, various field detectors showed different responses to dose rates, with PTW microDiamond identified as a suitable option for dose rates up to 2.2 kGy/s.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Jana Kretschmer, Leonie Brodbek, Carina Behrends, Fabian Kugel, Benjamin Koska, Christian Baeumer, Jorg Wulff, Beate Timmermann, Bjorn Poppe, Hui Khee Looe
Summary: The study aimed to quantify and correct for the perturbations of six point detectors in small proton fields created via three different delivery techniques. It was found that the microSilicon diode had the smallest perturbations among all investigated detectors, and the correction strategies based on the detector's K(x,y) were suitable for obtaining unperturbed lateral dose profiles and output factors. The findings of this study can guide the choice of point detectors in various proton fields and contribute to the development of a code of practice for small field proton dosimetry.
Article
Radiology, Nuclear Medicine & Medical Imaging
Sree Bash Chandra Debnath, Didier Tonneau, Carole Fauquet, Agnes Tallet, Anthony Goncalves, Julien Darreon
Summary: In this study, a new fiber-integrated X-ray inorganic detector is proposed and tested for its performance in dose linearity, repeatability, reproducibility, percentage depth dose distribution, and field output factor. The results show that the developed detector can accurately measure delivered dose to the region of interest, claim accurate depth dose distribution, and be a suitable candidate for beam characterization and quality assurance of LINAC system. The detector demonstrated excellent dosimetric characteristics in comparison with a microdiamond dosimeter and recent literature data.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Jose M. Larraga-Gutierrez, Olivia A. Garcia-Garduno, Jose A. Herrera-Gonzalez, Olga O. Galvan de la Cruz
Summary: By optimizing the focal spot size, Acuros (R) XB shows an acceptable agreement within 3% down to an MLC-field of 0.5 cm x 0.5 cm. The results suggest that a field output factor table down to a field size of 1.0 cm is required in the beam configuration model for planning static and modulated delivery of very small targets.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2021)
Article
Engineering, Biomedical
Isabel Blum, Tuba Tekin, Bjorn Delfs, Ann-Britt Schonfeld, Ralf-Peter Kapsch, Bjorn Poppe, Hui Khee Looe
Summary: This study investigates the behavior of two diode-type detectors in a transverse magnetic field under small field conditions, finding that the dose response is affected by the magnetic field. However, Monte Carlo simulations show good agreement with experimental results.
PHYSICS IN MEDICINE AND BIOLOGY
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Paul. H. Charles, Scott. B. Crowe, Tanya Kairn
Summary: This study calculated the correction factors required when using radiochromic film for small field dosimetry in lung equivalent material, showing that higher correction factors are needed for smaller field sizes and lower densities.
Article
Chemistry, Physical
Payam Azadeh, Saeede Amiri, Ahmad Mostaar, Ali Yaghobi Joybari, Reza Paydar
Summary: The study evaluated the performance and stability of MAGIC-f polymer gel dosimeter for small field dosimetry, showing good reliability but benchmarking against other dosimeters is necessary for becoming a three-dimensional dosimeter in small field dosimetry.
RADIATION PHYSICS AND CHEMISTRY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
B. Knaeusl, L. Langgartner, M. Stock, M. Janson, K. M. Furutani, C. J. Beltran, D. Georg, A. F. Resch
Summary: This study shows that a commercial treatment planning system (TPS) and GATE/Geant4 can accurately predict the dose for small proton fields using a collimator and pencil beam scanning. The dose agreement between TPS, GATE/Geant4, and measurements is within 1% for aperture diameters between 8 to 34 mm, but deviates up to 5% for smaller apertures. The introduction of a plastic taper improves the dose calculation accuracy in the entrance region for large apertures.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2023)
Article
Chemistry, Analytical
Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida
Summary: Nd-doped LaMgAl11O19 single crystals exhibit excellent photoluminescence and scintillation properties, with good afterglow characteristics after X-ray irradiation. The 1% and 3% Nd-doped LaMgAl11O19 samples show good linearity in different dynamic ranges.
Article
Polymer Science
Youbba Ould Salem, Halima Elazhar, Issiaka Traore, Jonathan Riffaud, Abdelmjid Nourreddine
Summary: This study investigates the use of RPL detectors for thermal neutron dosimetry and highlights the lack of results in the literature for CR-39 in this area. The measurements demonstrate the advantageous incorporation of RPL detectors for thermal neutron detection.
Article
Engineering, Biomedical
E. Cloutier, L. Beaulieu, L. Archambault
Summary: This study introduces a novel water-equivalent deformable dosimeter that can measure dose distribution and track deformation vector fields simultaneously with high precision. Experimental results showed that the dosimeter's measurements closely matched the results of treatment planning system calculations and complementary dose validation using another dosimetry system, demonstrating its accuracy in dose measurements under fixed and deformed conditions.
PHYSICS IN MEDICINE AND BIOLOGY
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Ann-Britt Schoenfeld, Karl Mund, Guanghua Yan, Andreas Alexander Schoenfeld, Hui Khee Looe, Bjoern Poppe
Summary: This study investigates the feasibility of using a neural network to deconvolve photon beam profiles in very small fields, proving its effectiveness and independence from delivery and scanning systems through experiments.
JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS
(2021)
Article
Biochemistry & Molecular Biology
Birgit Lohberger, Dietmar Glaenzer, Nicole Eck, Katharina Stasny, Anna Falkner, Andreas Leithner, Dietmar Georg
Summary: To overcome resistance to radiotherapy in chondrosarcomas, the combined treatment of DNA repair inhibitors (VE-821) with particle irradiation was investigated. The study showed that this combined treatment increased the radiosensitivity of chondrosarcoma cells and suppressed efficient DNA repair mechanisms, thus improving the efficiency of radiotherapy.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Loic Grevillot, Jhonnatan Osorio Moreno, Hermann Fuchs, Ralf Dreindl, Alessio Elia, Marta Bolsa-Ferruz, Markus Stock, Hugo Palmans
Summary: This study reports on the first implementation of the IBA Sphinx/Lynx QA device for daily QA of scanned proton and carbon ion beams. The performance of the equipment for protons and carbon ions was evaluated, and drifts and changes in machine performance were detected using daily trendlines. The study provides definitions of tolerances and action levels and compares them with those used in the literature. The device has been successfully implemented for over 2 years in a dual particle therapy facility, improving the efficiency and comprehensiveness of daily QA.
JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS
(2023)
Article
Engineering, Biomedical
P. van den Elzen, T. Sander, H. Palmans, M. McManus, N. Woodall, N. Lee, O. J. L. Fox, R. M. Jones, D. Angal-Kalinin, A. Subiel
Summary: This study aims to investigate the radiation response of alanine in different energy ranges. The results show that the alanine response is affected by large uncertainties and is strongly dependent on the x-ray beam energy in the low energy range. This study contributes to the establishment of alanine as a secondary standard dosimeter for low-energy x-ray sources.
PHYSICS IN MEDICINE AND BIOLOGY
(2023)
Article
Engineering, Biomedical
H. Cook, M. Simard, N. Niemann, C. Gillies, M. Osborne, M. Hussein, V Rompokos, H. Bouchard, G. Royle, J. Pettingell, H. Palmans, A. Lourenco
Summary: The objective of this study is to develop and characterize optimised tissue-equivalent materials for proton therapy due to the large uncertainties caused by existing phantom materials. A mathematical model was developed to formulate epoxy-resin based materials that are optimised for all relevant interactions of protons with matter, as well as photon interactions. The new materials have shown improved tissue-equivalence compared to existing materials.
PHYSICS IN MEDICINE AND BIOLOGY
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Gerd Heilemann, Lukas Zimmermann, Raphael Schotola, Wolfgang Lechner, Marco Peer, Joachim Widder, Gregor Goldner, Dietmar Georg, Peter Kuess
Summary: This study introduces a deep learning-based model that can generate deliverable DICOM RT treatment plans for prostate cancer radiotherapy. The model shows good agreement with the original data and has the potential to revolutionize treatment planning workflows.
Article
Oncology
Sandra Barna, Cynthia Meouchi, Andreas Franz Resch, Giulio Magrin, Dietmar Georg, Hugo Palmans
Summary: Investigated the impact of a 2D range modulator on microdosimetric spectra measured in proton and carbon ion beams. Optimizations were made through simulations, and the results show that the range modulator has no effect on radiation quality.
RADIOTHERAPY AND ONCOLOGY
(2023)
Editorial Material
Oncology
Dietmar Georg, Marianne C. Aznar, Uulke van der Heide, David Thwaites
RADIOTHERAPY AND ONCOLOGY
(2023)
Article
Oncology
Barbara Knaeusl, Franciska Lebbink, Piero Fossati, Erik Engwall, Dietmar Georg, Markus Stock
Summary: The retrospective study analyzed the clinical proton treatment strategy for pancreas patients with small moving tumors. The results showed that the treatment plans using synchrotron-based dose delivery with horizontal and vertical beams and robust optimization were robust against intra-fractional movements up to 3.7 mm. However, outliers were observed in some patients, indicating the need for continuous monitoring in clinical practice to identify cases with significant deviations.
Article
Radiology, Nuclear Medicine & Medical Imaging
B. Knaeusl, L. Langgartner, M. Stock, M. Janson, K. M. Furutani, C. J. Beltran, D. Georg, A. F. Resch
Summary: This study shows that a commercial treatment planning system (TPS) and GATE/Geant4 can accurately predict the dose for small proton fields using a collimator and pencil beam scanning. The dose agreement between TPS, GATE/Geant4, and measurements is within 1% for aperture diameters between 8 to 34 mm, but deviates up to 5% for smaller apertures. The introduction of a plastic taper improves the dose calculation accuracy in the entrance region for large apertures.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2023)
Article
Environmental Sciences
Sandra Barna, Cynthia Meouchi, Giulio Magrin, Anna Bianchi, Valeria Conte, Anna Selva, Markus Stock, Andreas Franz Resch, Dietmar Georg, Hugo Palmans
Summary: The first microdosimetric spectra measured with a miniaturised tissue-equivalent proportional counter in the clinical environment of the MedAustron ion-beam therapy facility were presented in this study. These spectra, gathered with a 62.4-MeV proton beam, were compared with microdosimetric spectra measured in the 62-MeV clinical proton beam of the CATANA beam line. Monte Carlo simulations using the Geant4 toolkit GATE and a fully commissioned clinical beam line model were performed to investigate the similarities and discrepancies between the measured data and simulations based on a simple and complex detector geometry.
RADIATION PROTECTION DOSIMETRY
(2023)
Article
Cell Biology
Vanessa Etschmaier, Dietmar Glaenzer, Nicole Eck, Ute Schaefer, Andreas Leithner, Dietmar Georg, Birgit Lohberger
Summary: Particle therapy (PT) offers a promising way to reduce the side effects of radiation oncology, especially in pediatric patients. A study on the influence of PT on growing bone demonstrated the occurrence of pathological and regenerative processes.
Meeting Abstract
Oncology
A. Azzi, G. Heilemann, D. Georg, S. A. Pawiro, T. Mart, W. Lechner
RADIOTHERAPY AND ONCOLOGY
(2023)
Meeting Abstract
Oncology
G. Heilemann, M. Buschmann, W. Lechner, V. M. Dick, F. Eckert, M. Heilmann, H. Herrmann, M. Hudelist-Venz, M. Moll, J. Knoth, S. Konrad, I. M. Simek, C. Thiele, Z. Alexandru-Teodor, D. Georg, J. Widder, T. Petra
RADIOTHERAPY AND ONCOLOGY
(2023)
Meeting Abstract
Oncology
W. Lechner
RADIOTHERAPY AND ONCOLOGY
(2023)