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Articles 1 - 19 of 19
Full-Text Articles in Engineering
Effect Of A Static Magnetic Field On Nanodosimetric Quantities In A Dna Volume, Peter Lazarakis, Marion U. Bug, Elisabetta Gargioni, Susanna Guatelli, Sabastien Incerti, Hans Rabus, Anatoly B. Rosenfeld
Effect Of A Static Magnetic Field On Nanodosimetric Quantities In A Dna Volume, Peter Lazarakis, Marion U. Bug, Elisabetta Gargioni, Susanna Guatelli, Sabastien Incerti, Hans Rabus, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Abstract Purpose: With the advent of magnetic resonance imaging (MRI)-guided radiation therapy it is becoming increasingly important to consider the potential influence of a magnetic field on ionising radiation. This paper aims to study the effect of a magnetic field on the track structure of radiation to determine if the biological effectiveness may be altered. Methods: Using the Geant4-DNA (GEometry ANd Tracking 4) Monte Carlo simulation toolkit, nanodosimetric track structure parameters were calculated for electrons, protons and alpha particles moving in transverse magnetic fields up to 10 Tesla. Applying the model proposed by Garty et al., the track structure parameters …
The Geant4-Dna Project, S Incerti, G Baldacchino, M Bernal, R Capra, C Champion, Z Francis, S Guatelli, P Gueye, A Mantero, B Mascialino, P Moretto, P Nieminen, Anatoly B. Rosenfeld, C Villagrasa, C Zacharatou
The Geant4-Dna Project, S Incerti, G Baldacchino, M Bernal, R Capra, C Champion, Z Francis, S Guatelli, P Gueye, A Mantero, B Mascialino, P Moretto, P Nieminen, Anatoly B. Rosenfeld, C Villagrasa, C Zacharatou
Anatoly Rozenfeld
The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ionising radiation at the cellular and sub-cellular scale. This project was originally initiated by the European Space Agency for the prediction of deleterious effects of radiation that may affect astronauts during future long duration space exploration missions. In this paper, the Geant4-DNA collaboration presents an overview of the whole ongoing project, including its most recent developments already available in the last Geant4 public release (9.3 …
Alpha Particle And Proton Relative Thermoluminescence Efficiencies In Lif:Mg,Cu,P:Is Track Structure Theory Up To The Task?, Y S. Horowitz, D Siboni, L Oster, J Livingstone, S Guatelli, Anatoly B. Rosenfeld, D Emfietzoglou, P Bilski, B Obryk
Alpha Particle And Proton Relative Thermoluminescence Efficiencies In Lif:Mg,Cu,P:Is Track Structure Theory Up To The Task?, Y S. Horowitz, D Siboni, L Oster, J Livingstone, S Guatelli, Anatoly B. Rosenfeld, D Emfietzoglou, P Bilski, B Obryk
Anatoly Rozenfeld
"Low-energy alpha particle and proton heavy charged particle (HCP) relative thermoluminescence (TL) efficiencies are calculated for the major dosimetric glow peak in LiF:Mg,Cu,P (MCP-N) in the framework of track structure theory (TST). The calculations employ previously published TRIPOS-E Monte Carlo track segment values of the radial dose in condensed phase LiF calculated at the Instituto National de Investigaciones Nucleares (Mexico) and experimentally measured normalised Co-60 gamma-induced TL doseresponse functions, f(D), carried out at the Institute of Nuclear Physics (Poland). The motivation for the calculations is to test the validity of TST in a TL system in which f(D) is not …
Megavoltage Cone Beam Ct Near Surface Dose Measurements: Potential Implications For Breast Radiotherapy, Alexandra Quinn, Lois C. Holloway, Dean Cutajar, Nicholas Hardcastle, Anatoly B. Rosenfeld, Peter E. Metcalfe
Megavoltage Cone Beam Ct Near Surface Dose Measurements: Potential Implications For Breast Radiotherapy, Alexandra Quinn, Lois C. Holloway, Dean Cutajar, Nicholas Hardcastle, Anatoly B. Rosenfeld, Peter E. Metcalfe
Anatoly Rozenfeld
Purpose: Cone beam computed tomography (CBCT) is fast becoming standard on modern linear accelerators. CBCT increases the dose to regions within and outside the treatment field, potentially increasing secondary cancer induction and toxicity. This study quantified megavoltage (MV) CBCT skin dose and compared it to skin dose delivered during standard tangential breast radiotherapy. Method: Dosimetry was performed both in- and out-of-field using thermoluminescent dosimeters (TLDs) and a metal-oxide-semiconductor-field-effect-transistor (MOSFET) detector specifically designed for skin dosimetry; these were placed superficially on a female anthropomorphic phantom. Results: The skin dose from a single treatment fraction ranged from 0.5 to 1.4 Gy on …
Studies Of The Characteristics Of A Silicon Neutron Sensor, Igor E. Anokhin, Oleg S. Zinets, Anatoly B. Rosenfeld, Michael L. Lerch, M. Yudelev, V. L. Perevertaylo, Mark I. Reinhard, Marco Petasecca
Studies Of The Characteristics Of A Silicon Neutron Sensor, Igor E. Anokhin, Oleg S. Zinets, Anatoly B. Rosenfeld, Michael L. Lerch, M. Yudelev, V. L. Perevertaylo, Mark I. Reinhard, Marco Petasecca
Anatoly Rozenfeld
Electrical characteristics and neutron dosimetry properties of silicon based p-i-n diodes are presented in support of the applications in the sensors for beam monitoring and medical physics. Both the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of silicon planar p-i-n diode sensors with cylindrical geometry have been theoretically modeled and experimentally measured. The shifts of the forward and reverse diode characteristics of the sensors versus the neutron dose have been obtained. It is shown that the neutron irradiation caused shift of the forward voltage of the p-i-n diodes is proportional to the current at which it is measured in the case …
Magneto-Radiotherapy: Effect Of Magnetic Field On Dose Distribution And Rbe, Heidi Nettelbeck, Anatoly B. Rosenfeld, George J. Takacs, Michael L. Lerch
Magneto-Radiotherapy: Effect Of Magnetic Field On Dose Distribution And Rbe, Heidi Nettelbeck, Anatoly B. Rosenfeld, George J. Takacs, Michael L. Lerch
Anatoly Rozenfeld
Magneto-radiotherapy is the application of magnetic fields during radiotherapy procedures. It aims to improve the quality of cancer treatment by altering the dose deposition of charged particles in the tissue volume being targeted. Our research has focused on applying the concept of magneto-radiotherapy to conventional linac treatment and MRT (Microbeam Radiation Therapy) oncology modalities.
Evaluation Of Silicon Detectors With Integrated Jfet For Biomedical Applications, Mitra Safavi-Naeini, D. Franklin, Michael L. Lerch, Marco Petasecca, Giorgio U. Pignatel, Mark I. Reinhard, G. F. Dalla Betta, N. Zorzi, Anatoly B. Rosenfeld
Evaluation Of Silicon Detectors With Integrated Jfet For Biomedical Applications, Mitra Safavi-Naeini, D. Franklin, Michael L. Lerch, Marco Petasecca, Giorgio U. Pignatel, Mark I. Reinhard, G. F. Dalla Betta, N. Zorzi, Anatoly B. Rosenfeld
Anatoly Rozenfeld
This paper presents initial results from electrical, spectroscopic and ion beam induced charge (IBIC) characterisation of a novel silicon PIN detector, featuring an on-chip n -channel JFET and matched feedback capacitor integrated on its p-side (frontside). This structure reduces electronic noise by minimising stray capacitance and enables highly efficient optical coupling between the detector back-side and scintillator, providing a fill factor of close to 100%. The detector is specifically designed for use in high resolution gamma cameras, where a pixellated scintillator crystal is directly coupled to an array of silicon photodetectors. The on-chip JFET is matched with the photodiode capacitance …
A Dual Scintillator - Dual Silicon Photodiode Detector Module For Intraoperative Gamma\Beta Probe And Portable Anti-Compton Spectrometer, Anatoly B. Rosenfeld, Michael Lf Lerch, M. Chan, Dean Inwood, George J. Takacs, Bong Soo Lee, A F. Gektin, V L Perevertaylo
A Dual Scintillator - Dual Silicon Photodiode Detector Module For Intraoperative Gamma\Beta Probe And Portable Anti-Compton Spectrometer, Anatoly B. Rosenfeld, Michael Lf Lerch, M. Chan, Dean Inwood, George J. Takacs, Bong Soo Lee, A F. Gektin, V L Perevertaylo
Anatoly Rozenfeld
A new approach has been investigated for the miniaturization and simplification of intraoperative gamma and beta probes that have recently found application in radioguided surgery and sentinel lymph node biopsy. The probe design that is based on dual annular scintillators coupled to specially designed silicon concentric dual photodiode (CDPD). This approach allows us to avoid fiber optics coupling and PMTs. Two channels readout front-end electronics including shaper amplifier attached directly to the back of the detector module has been proposed. Two geometries of Si dual photodiodes coupled to CsI(Tl) annular scintillators with light masking between them were fabricated and investigated. …
Neutron Dosimeter Development Based On Medipix2, Mohd Amir R. Othman, Marco Petasecca, Susanna Guatelli, J. Uher, Damion Marinaro, Dale A. Prokopovich, Mark I. Reinhard, Michael L. F. Lerch, J. Jakubek, S. Pospisil, Anatoly B. Rosenfeld
Neutron Dosimeter Development Based On Medipix2, Mohd Amir R. Othman, Marco Petasecca, Susanna Guatelli, J. Uher, Damion Marinaro, Dale A. Prokopovich, Mark I. Reinhard, Michael L. F. Lerch, J. Jakubek, S. Pospisil, Anatoly B. Rosenfeld
Anatoly Rozenfeld
A novel neutron dosimetry system for avionics and space applications is described. The new dosimetric system is based on Medipix2, a high density silicon based pixilated detector with integrated readout and digital interface circuitry. Real time dose equivalent response to fast neutron fields with flattened energy response is achieved through the coupling of a structured variable thickness polyethylene (PE) over layer with the high density pixilated detector. Experimental results obtained to 14 MeV D-T and Am-Be neutron fields are described along with a comparison to results obtained with GEANT4 simulations.
Urethral Alarm Probe For Permanent Prostate Implants, Dean Cutajar, Michael L. Lerch, George J. Takacs, Bong Soo Lee, Y Chin, J Bucci, M Zaider, M Zelefsky, J. Yamada, Gil'ad Cohen, V L Perevertaylo, Anatoly B. Rosenfeld
Urethral Alarm Probe For Permanent Prostate Implants, Dean Cutajar, Michael L. Lerch, George J. Takacs, Bong Soo Lee, Y Chin, J Bucci, M Zaider, M Zelefsky, J. Yamada, Gil'ad Cohen, V L Perevertaylo, Anatoly B. Rosenfeld
Anatoly Rozenfeld
We have developed a urethral dosimetry system for real time dose verification along the urethra during permanent implant prostate brachytherapy. The urethral alarm probe uses “spectroscopic dosimetry” to calculate the dose rate along the urethra in real time. The application of spectroscopic dosimetry for the urethral alarm probe was verified using Monte Carlo calculations. In phantom depth dose measurements as well as isotropy measurements were performed to verify the usefulness of the urethra alarm probe as an in vivo real time dosimeter.
Magneto-Radiotherapy: Making The Electrons Conform, Heidi Nettelbeck, Michael L. Lerch, George J. Takacs, Anatoly B. Rosenfeld
Magneto-Radiotherapy: Making The Electrons Conform, Heidi Nettelbeck, Michael L. Lerch, George J. Takacs, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Magneto-radiotherapy is the application of magnetic fields during radiotherapy procedures. It aims to improve the quality of cancer treatment by using magnetic fields to alter the dose-deposition of secondary electrons in tissue. This work compares the performance of PENELOPE and EGS4 MC codes for magnetic fields applied to conventional photon beams. It also investigates the effect of a magnetic field on the electron spectrum and explores the novel idea of applying magnetic fields to MRT (Microbeam Radiation Therapy) for the treatment infantile brain tumours.
The Teaching/Research Nexus And Internationalisation: An Action Research Project In Radiation Physics, Susanna Guatelli, Catherine Layton, Dean Cutajar, Anatoly B. Rosenfeld
The Teaching/Research Nexus And Internationalisation: An Action Research Project In Radiation Physics, Susanna Guatelli, Catherine Layton, Dean Cutajar, Anatoly B. Rosenfeld
Anatoly Rozenfeld
This paper attempts to unpack the teaching and learning experiences of academics and students when a new way of teaching radiation physics was introduced. In an attempt to articulate the University of Wollongong’s commitment to the enhancement of the teaching/research nexus and to the development of learning communities, staff of the School of Physics in the Faculty of Engineering at University of Wollongong (UOW) implemented an action research project teaching scientific computing methodologies used in radiation physics to a combined laboratory class of postgraduates and undergraduates. The design of the practical laboratory classes took account of the expected heterogeneous computing …
Nanoscale Characterization Of Ion Tracks: Mc Simulations Versus Analytical Approach, M U. Bug, E Surdutovich, H Rabus, Anatoly B. Rosenfeld, A V. Solov'yov
Nanoscale Characterization Of Ion Tracks: Mc Simulations Versus Analytical Approach, M U. Bug, E Surdutovich, H Rabus, Anatoly B. Rosenfeld, A V. Solov'yov
Anatoly Rozenfeld
The goal of this work was to investigate the agreement of physical parameters related to the particle track structure on the nanometer scale, obtained by means of a detailed track structure simulation (PTra) as well as by a rapid analytical approach. Parameters describing the tracks of secondary electrons produced by 0.3 MeV/u C6+-ions were of particular interest as those particles are densely ionizing. For this purpose, the target volume in form of a nanometric water cylinder was positioned at different radial distances from the ion trajectory and track structure parameters were determined as function of the radial distance. While the …
Comparison Of Nanodosimetric Parameters Of Track Structure Calculated By The Monte Carlo Codes Geant4-Dna And Ptra, P Lazarakis, M U. Bug, E Gargioni, S Guatelli, H Rabus, Anatoly B. Rosenfeld
Comparison Of Nanodosimetric Parameters Of Track Structure Calculated By The Monte Carlo Codes Geant4-Dna And Ptra, P Lazarakis, M U. Bug, E Gargioni, S Guatelli, H Rabus, Anatoly B. Rosenfeld
Anatoly Rozenfeld
The concept of nanodosimetry is based on the assumption that initial damage to cells is related to the number of ionizations (the ionization cluster size) directly produced by single particles within, or in the close vicinity of, short segments of DNA. The ionization cluster-size distribution and other nanodosimetric quantities, however, are not directly measurable in biological targets and our current knowledge is mostly based on numerical simulations of particle tracks in water, calculating track structure parameters for nanometric target volumes. The assessment of nanodosimetric quantities derived from particle-track calculations using different Monte Carlo codes plays, therefore, an important role for …
Advanced Semiconductor Dosimetry In Radiation Therapy, Anatoly B. Rosenfeld
Advanced Semiconductor Dosimetry In Radiation Therapy, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Modern radiation therapy is very conformal, resulting in a complexity of delivery that leads to many small radiation fields with steep dose gradients, increasing error probability. Quality assurance in delivery of such radiation fields is paramount and requires real time and high spatial resolution dosimetry. Semiconductor radiation detectors due to their small size, ability to operate in passive and active modes and easy real time multichannel readout satisfy many aspects of in vivo and in a phantom quality assurance in modern radiation therapy. Update on the recent developments and improvements in semiconductor radiation detectors and their application for quality assurance …
A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld
A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Purpose: A real-time in vivo dosimetric verification method using metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters has been developed for patient dosimetry in high-dose rate (HDR) intracavitary brachytherapy of nasopharyngeal carcinoma (NPC). Methods: The necessary calibration and correction factors for MOSFET measurements in 192Iridium source were determined in a water phantom. With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system. Results: Five MOSFETs were independently calibrated with the HDR source, yielding calibration factors of 0.48 ± 0.007 cGymV. …
Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome
Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome
Anatoly Rozenfeld
Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed "Super Sampling" involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances receiving …
X-Tream: A Novel Dosimetry System For Synchrotron Microbeam Radiation Therapy, M Petasecca, A Cullen, I Fuduli, A Espinoza, C Porumb, C Stanton, A H. Aldosari, E Brauer-Krisch, H Requardt, A Bravin, V Perevertaylo, Anatoly B. Rosenfeld, M L. F Lerch
X-Tream: A Novel Dosimetry System For Synchrotron Microbeam Radiation Therapy, M Petasecca, A Cullen, I Fuduli, A Espinoza, C Porumb, C Stanton, A H. Aldosari, E Brauer-Krisch, H Requardt, A Bravin, V Perevertaylo, Anatoly B. Rosenfeld, M L. F Lerch
Anatoly Rozenfeld
Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses …
Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld
Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Silicon microdosimeters for the characterisation of mixed radiation fields relevant to the space radiation environment have been under continual development at the Centre for Medical Radiation Physics for over a decade. These devices are useful for the prediction of single event upsets in microelectronics and for radiation protection of spacecraft crew. The latest development in silicon microdosimetry is a family of large-area n-SOI microdosimeters for real-time dosimetry in space radiation environments. The response of n-SOI microdosimeters to 2 MeV H and 5.5 MeV He ions has been studied to investigate their charge collection characteristics. The studies have confirmed 100% yield …