ORCID Profile
0000-0002-0691-6883
Current Organisations
Finnish Institute for Health and Welfare
,
ANSTO - Australian Synchrotron
,
CSIRO
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Synchrotrons; Accelerators; Instruments and Techniques | Timber, Pulp and Paper | Manufacturing Engineering | Manufacturing Processes and Technologies (excl. Textiles) | Materials Engineering | Metals and Alloy Materials | Numerical Modelling and Mechanical Characterisation | Petroleum and Reservoir Engineering
ANZSRC Socio-Economic Objective (SEO)
Wood, Wood Products and Paper not elsewhere classified | Oil and Gas Extraction | Structural Metal Products | Fabricated Metal Products not elsewhere classified |
Related Links
Publications
Feasibility study of propagation-based phase-contrast X-ray lung imaging on the Imaging and Medical beamline at the Australian Synchrotron
Publisher: International Union of Crystallography (IUCr)
Date: 30-01-2014
Methods for dynamic synchrotron X-ray respiratory imaging in live animals
Publisher: International Union of Crystallography (IUCr)
Date: 2020
DOI: 10.1107/S1600577519014863
Abstract: Small-animal physiology studies are typically complicated, but the level of complexity is greatly increased when performing live-animal X-ray imaging studies at synchrotron and compact light sources. This group has extensive experience in these types of studies at the SPring-8 and Australian synchrotrons, as well as the Munich Compact Light Source. These experimental settings produce unique challenges. Experiments are always performed in an isolated radiation enclosure not specifically designed for live-animal imaging. This requires equipment adapted to physiological monitoring and test-substance delivery, as well as shuttering to reduce the radiation dose. Experiment designs must also take into account the fixed location, size and orientation of the X-ray beam. This article describes the techniques developed to overcome the challenges involved in respiratory X-ray imaging of live animals at synchrotrons, now enabling increasingly sophisticated imaging protocols.
Synchrotron microbeam radiotherapy evokes a different early tumor immunomodulatory response to conventional radiotherapy in EMT6.5 mammary tumors
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.RADONC.2019.01.006
Abstract: Synchrotron microbeam radiation therapy (MRT) is a new, evolving form of radiotherapy that has potential for clinical application. Several studies have shown in preclinical models that synchrotron MRT achieves equivalent tumor control to conventional radiotherapy (CRT) but with significantly reduced normal tissue damage. To explore differences between these two modalities, we assessed the immune cell infiltrate into EMT6.5 mammary tumors after CRT and MRT. CRT induced marked increases in tumor-associated macrophages and neutrophils while there were no increases in these populations following MRT. In contrast, there were higher numbers of T cells in the MRT treated tumors. There were also increased levels of CCL2 by immunohistochemistry in tumors subjected to CRT, but not to MRT. Conversely, we found that MRT induced higher levels of pro-inflammatory genes in tumors than CRT. Our data are the first to demonstrate substantial differences in macrophage, neutrophil and T cell numbers in tumors following MRT versus CRT, providing support for the concept that MRT evokes a different immunomodulatory response in tumors compared to CRT.
In Vitro Study of Genes and Molecular Pathways Differentially Regulated by Synchrotron Microbeam Radiotherapy
Publisher: Radiation Research Society
Date: 19-11-2014
DOI: 10.1667/RR13778.1
Interpreting ionisation-chamber measurements as a function of wiggler field at a synchrotron source
Publisher: IOP Publishing
Date: 27-11-2018
Energy spectra considerations for synchrotron radiotherapy trials on the ID17 bio-medical beamline at the European Synchrotron Radiation Facility
Publisher: International Union of Crystallography (IUCr)
Date: 26-06-2015
DOI: 10.1107/S1600577515008115
Abstract: The aim of this study was to validate the kilovoltage X-ray energy spectrum on the ID17 beamline at the European Synchrotron Radiation Facility (ESRF). The purpose of such validation was to provide an accurate energy spectrum as the input to a computerized treatment planning system, which will be used in synchrotron microbeam radiotherapy trials at the ESRF. Calculated and measured energy spectra on ID17 have been reported previously but recent additions and safety modifications to the beamline for veterinary trials warranted a fresh investigation. The authors used an established methodology to compare X-ray attenuation measurements in copper sheets (referred to as half value layer measurements in the radiotherapy field) with the predictions of a theoretical model. A cylindrical ionization chamber in air was used to record the relative attenuation of the X-ray beam intensity by increasing thicknesses of high-purity copper sheets. The authors measured the half value layers in copper for two beamline configurations, which corresponded to differing spectral conditions. The authors obtained good agreement between the measured and predicted half value layers for the two beamline configurations. The measured first half value layer was 1.754 ± 0.035 mm Cu and 1.962 ± 0.039 mm Cu for the two spectral conditions, compared with theoretical predictions of 1.763 ± 0.039 mm Cu and 1.984 ± 0.044 mm Cu, respectively. The calculated mean energies for the two conditions were 105 keV and 110 keV and there was not a substantial difference in the calculated percentage depth dose curves in water between the different spectral conditions. The authors observed a difference between their calculated energy spectra and the spectra previously reported by other authors, particularly at energies greater than 100 keV. The validation of the beam spectrum by the copper half value layer measurements means the authors can provide an accurate spectrum as an input to a treatment planning system for the forthcoming veterinary trials of microbeam radiotherapy to spontaneous tumours in cats and dogs.
A quantitative study of monochromatic X-ray transmission through zinc wires
Publisher: International Union of Crystallography (IUCr)
Date: 10-07-2012
Micro-Computed Tomography Beamline of the Australian Synchrotron: Micron-Size Spatial Resolution X-ray Imaging
Publisher: MDPI AG
Date: 18-01-2023
DOI: 10.3390/APP13031317
Abstract: The first new beamline of the BRIGHT project—involving the construction of eight new beamlines at the Australian Synchrotron—is the Micro-Computed Tomography (MCT) beamline. MCT will extend the facility’s capability for higher spatial resolution X-ray-computed tomographic imaging allowing for commensurately smaller s les in comparison with the existing Imaging and Medical Beamline (IMBL). The source is a bending-magnet and it is operating in the X-ray energy range from 8 to 40 keV. The beamline provides important new capability for a range of biological and material-science applications. Several imaging modes will be offered such as various X-ray phase-contrast modalities (propagation-based, grating-based, and speckle-based), in addition to conventional absorption contrast. The unique properties of synchrotron radiation sources (high coherence, energy tunability, and high brightness) are predominantly well-suited for producing phase contrast data. An update on the progress of the MCT project in delivering high-spatial-resolution imaging (in the order of micron size) of mm-scale objects will be presented in detail with some imaging results from the hot-commissioning stage.
CT dosimetry at the Australian Synchrotron for 25–100 keV photons and 35–160 mm-diameter biological specimens
Publisher: International Union of Crystallography (IUCr)
Date: 15-02-2019
DOI: 10.1107/S1600577518018015
Abstract: The dose length product (DLP) method for medical computed tomography (CT) dosimetry is applied on the Australian Synchrotron Imaging and Medical Beamline (IMBL). Beam quality is assessed from copper transmission measurements using image receptors, finding near 100% (20 keV), 3.3% (25 keV) and 0.5% (30–40 keV) relative contributions from third-harmonic radiation. The flat-panel-array medical image receptor is found to have a non-linear dose response curve. The amount of radiation delivered during an axial CT scan is measured as the dose in air alone, and inside cylindrical PMMA phantoms with diameters 35–160 mm for mono-energetic radiation 25–100 keV. The radiation output rate for the IMBL is comparable with that used for medical CT. Results are presented as the ratios of CT dose indices (CTDI) inside phantoms to in air with no phantom. Ratios are compared for the IMBL against medical CT where bow-tie filters shape the beam profile to reduce the absorbed dose to surface organs. CTDI ratios scale measurements in air to estimate the volumetric CTDI representing the average dose per unit length, and the dose length product representing the absorbed dose to the scanned volume. Medical CT dose calculators use the DLP, beam quality, axial collimation and helical pitch to estimate organ doses and the effective dose. The effective dose per unit DLP for medical CT is presented as a function of body region, beam energy and s le sizes from neonate to adult.
Empirical study of the spatial variation of recombination, polarity and polarization effects in ionization chambers
Publisher: Elsevier BV
Date: 2019
Absolute x-ray dosimetry on a synchrotron medical beam line with a graphite calorimeter
Publisher: Wiley
Date: 10-04-2014
DOI: 10.1118/1.4870387
Abstract: The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and provide confidence in the first implementation of a graphite calorimeter on a synchrotron medical beam line. The graphite calorimeter has a core which rises in temperature when irradiated by the beam. A collimated x-ray beam from the synchrotron with well-defined edges was used to partially irradiate the core. Two filtration sets were used, one corresponding to an average beam energy of about 80 keV, with dose rate about 50 Gy/s, and the second filtration set corresponding to average beam energy of 90 keV, with dose rate about 20 Gy/s. The temperature rise from this beam was measured by a calibrated thermistor embedded in the core which was then converted to absorbed dose to graphite by multiplying the rise in temperature by the specific heat capacity for graphite and the ratio of cross-sectional areas of the core and beam. Conversion of the measured absorbed dose to graphite to absorbed dose to water was achieved using Monte Carlo calculations with the EGSnrc code. The air kerma measurements from the free-air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. Absolute measurements of the IMBL dose rate were made using the graphite calorimeter and compared to measurements with the free-air chamber. The measurements were at three different depths in graphite and two different filtrations. The calorimetry measurements at depths in graphite show agreement within 1% with free-air chamber measurements, when converted to absorbed dose to water. The calorimetry at the surface and free-air chamber results show agreement of order 3% when converted to absorbed dose to water. The combined standard uncertainty is 3.9%. The good agreement of the graphite calorimeter and free-air chamber results indicates that both devices are performing as expected. Further investigations at higher dose rates than 50 Gy/s are planned. At higher dose rates, recombination effects for the free-air chamber are much higher and expected to lead to much larger uncertainties. Since the graphite calorimeter does not have problems associated with dose rate, it is an appropriate primary standard detector for the synchrotron IMBL x rays and is the more accurate dosimeter for the higher dose rates expected in radiotherapy applications.
Estimating the absolute flux distribution for a synchrotron X-ray beam using ionization-chamber measurements with various filters
Publisher: International Union of Crystallography (IUCr)
Date: 11-08-2017
DOI: 10.1107/S1600577517009274
Abstract: It is shown that an extensive set of accurate ionization-chamber measurements with a primary polychromatic synchrotron X-ray beam transmitted through various filter combinations/thicknesses can be used to quite effectively estimate the absolute flux distribution. The basic technique is simple but the `inversion' of the raw data to extract the flux distribution is a fundamentally ill-posed problem. It is demonstrated, using data collected at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron, that the absolute flux can be quickly and reliably estimated if a suitable choice of filters is made. Results are presented as a function of the magnetic field (from 1.40 to 4.00 T) of the superconducting multi-pole wiggler insertion device installed at IMBL. A non-linear least-squares refinement of the data is used to estimate the incident flux distribution and then comparison is made with calculations from the programs SPECTRA , XOP and spec.exe . The technique described is important not only in estimating flux itself but also for a variety of other, derived, X-ray properties such as beam quality, power density and absorbed-dose rate. The applicability of the technique with a monochromatic X-ray beam for which there is significant harmonic contamination is also demonstrated. Whilst absolute results can also be derived in this monochromatic beam case, relative (integrated) flux values are sufficient for our primary aim of establishing reliable determinations of the percentages of the various harmonic components.
Analysis and interpretation of the first monochromatic X-ray tomography data collected at the Australian Synchrotron Imaging and Medical beamline
Publisher: International Union of Crystallography (IUCr)
Date: 11-07-2012
Absorbed dose determination in kilovoltage X-ray synchrotron radiation using alanine dosimeters
Publisher: Springer Science and Business Media LLC
Date: 09-2016
DOI: 10.1007/S13246-016-0479-1
Abstract: Alanine dosimeters from the National Physical Laboratory (NPL) in the UK were irradiated using kilovoltage synchrotron radiation at the imaging and medical beam line (IMBL) at the Australian Synchrotron. A 20 × 20 mm
Characterization of a synthetic single crystal diamond detector for dosimetry in spatially fractionated synchrotron X-ray fields
Publisher: Wiley
Date: 16-06-2016
DOI: 10.1118/1.4953833
Abstract: Modern radiotherapy modalities often use small or nonstandard fields to ensure highly localized and precise dose delivery, challenging conventional clinical dosimetry protocols. The emergence of preclinical spatially fractionated synchrotron radiotherapies with high dose-rate, sub-millimetric parallel kilovoltage x-ray beams, has pushed clinical dosimetry to its limit. A commercially available synthetic single crystal diamond detector designed for small field dosimetry has been characterized to assess its potential as a dosimeter for synchrotron microbeam and minibeam radiotherapy. Experiments were carried out using a synthetic diamond detector on the imaging and medical beamline (IMBL) at the Australian Synchrotron. The energy dependence of the detector was characterized by cross-referencing with a calibrated ionization chamber in monoenergetic beams in the energy range 30-120 keV. The dose-rate dependence was measured in the range 1-700 Gy/s. Dosimetric quantities were measured in filtered white beams, with a weighted mean energy of 95 keV, in broadbeam and spatially fractionated geometries, and compared to reference dosimeters. The detector exhibits an energy dependence however, beam quality correction factors (kQ) have been measured for energies in the range 30-120 keV. The kQ factor for the weighted mean energy of the IMBL radiotherapy spectrum, 95 keV, is 1.05 ± 0.09. The detector response is independent of dose-rate in the range 1-700 Gy/s. The percentage depth dose curves measured by the diamond detector were compared to ionization chambers and agreed to within 2%. Profile measurements of microbeam and minibeam arrays were performed. The beams are well resolved and the full width at halfmaximum agrees with the nominal width of the beams. The peak to valley dose ratio (PVDR) calculated from the profiles at various depths in water agrees within experimental error with PVDR calculations from Gafchromic film data. The synthetic diamond detector is now well characterized and will be used to develop an experimental dosimetry protocol for spatially fractionated synchrotron radiotherapy.
Applications of heterogeneous computing in computational and simulation science
Publisher: Inderscience Publishers
Date: 2013
High spatial resolution dosimetric response maps for radiotherapy ionization chambers measured using kilovoltage synchrotron radiation
Publisher: IOP Publishing
Date: 28-10-2015
DOI: 10.1088/0031-9155/60/22/8625
Abstract: Small circular beams of synchrotron radiation (0.1 mm and 0.4 mm in diameter) were used to irradiate ionization chambers of the types commonly used in radiotherapy. By scanning the chamber through the beam and measuring the ionization current, a spatial map of the dosimetric response of the chamber was recorded. The technique is able to distinguish contributions to the large-field ionization current from the chamber walls, central electrode and chamber stem. Scans were recorded for the NE 2571 Farmer chamber, the PTW 30013, IBA FC65-G Farmer-type chambers, the NE 2611A and IBA CC13 thimble chambers, the PTW 31006 and 31014 pinpoint chambers, the PTW Roos and Advanced Markus plane-parallel chambers, and the PTW 23342 thin-window soft x-ray chamber. In all cases, large contributions to the response arise from areas where the incident beam grazes the cavity surfaces. Quantitative as well as qualitative information about the relative chamber response was extracted from the maps, including the relative contribution of the central electrode. Line scans using monochromatic beams show the effect of the photon energy on the chamber response. For Farmer-type chambers, a simple Monte Carlo model was in good agreement with the measured response.
X-ray beam hardening based material recognition in micro-imaging
Publisher: IOP Publishing
Date: 30-08-2011
Characterizing Grain-Oriented Silicon Steel Sheet Using Automated High-Resolution Laue X-ray Diffraction
Publisher: Springer Science and Business Media LLC
Date: 11-09-2017
On the evolution and relative merits of hard X-ray phase-contrast imaging methods
Publisher: The Royal Society
Date: 06-03-2014
Abstract: This review provides a brief overview, albeit from a somewhat personal perspective, of the evolution and key features of various hard X-ray phase-contrast imaging (PCI) methods of current interest in connection with translation to a wide range of imaging applications. Although such methods have already found wide-ranging applications using synchrotron sources, application to dynamic studies in a laboratory/clinical context, for ex le for in vivo imaging, has been slow due to the current limitations in the brilliance of compact laboratory sources and the availability of suitable high-performance X-ray detectors. On the theoretical side, promising new PCI methods are evolving which can record both components of the phase gradient in a single exposure and which can accept a relatively large spectral bandpass. In order to help to identify the most promising paths forward, we make some suggestions as to how the various PCI methods might be compared for performance with a particular view to identifying those which are the most efficient, given the fact that source performance is currently a key limiting factor on the improved performance and applicability of PCI systems, especially in the context of dynamic s le studies. The rapid ongoing development of both suitable improved sources and detectors gives strong encouragement to the view that hard X-ray PCI methods are poised for improved performance and an even wider range of applications in the near future.
Image guidance protocol for synchrotron microbeam radiation therapy
Publisher: International Union of Crystallography (IUCr)
Date: 28-01-2016
DOI: 10.1107/S1600577515022894
Abstract: The protocol for image-guided microbeam radiotherapy (MRT) developed for the Australian Synchrotron's Imaging and Medical Beamline (IMBL) is described. The protocol has been designed for the small-animal MRT station of IMBL to enable future preclinical trials on rodents. The image guidance procedure allows for low-dose monochromatic imaging at 50 keV and subsequent semi-automated s le alignment in 3D with sub-100 µm accuracy. Following the alignment, a beamline operation mode change is performed and the relevant beamline components are automatically aligned for the treatment (pink) beam to be delivered on the s le. Here, the small-animal MRT station, the parameters and procedures for the image guidance protocol, as well as the experimental imaging results using phantoms are described. Furthermore, the experimental validation of the protocol using 3D PRESAGE ® dosimeters is reported. It is demonstrated that the s le alignment is maintained after the mode change and the treatment can be delivered within the same spatial accuracy of 100 µm. The results indicate that the proposed approach is viable for preclinical trials of small-animal MRT.
X-ray microbeam measurements with a high resolution scintillator fibre-optic dosimeter
Publisher: Springer Science and Business Media LLC
Date: 29-09-2017
DOI: 10.1038/S41598-017-12697-6
Abstract: Synchrotron microbeam radiation therapy is a novel external beam therapy under investigation, that uses highly brilliant synchrotron x-rays in microbeams 50 μ m width, with separation of 400 μ m, as implemented here. Due to the fine spatial fractionation dosimetry of these beams is a challenging and complicated problem. In this proof-of-concept work, we present a fibre optic dosimeter that uses plastic scintillator as the radiation conversion material. We claim an ideal one-dimensional resolution of 50 μ m. Using plastic scintillator and fibre optic makes this dosimeter water-equivalent, a very desirable dosimetric property. The dosimeter was tested at the Australian Synchrotron, on the Imaging and Medical Beam-Line. The in idual microbeams were able to be resolved and the peak-to-valley dose ratio and the full width at half maximum of the microbeams was measured. These results are compared to a semiconductor strip detector of the same spatial resolution. A percent depth dose was measured and compared to data acquired by an ionisation chamber. The results presented demonstrate significant steps towards the development of an optical dosimeter with the potential to be applied in quality assurance of microbeam radiation therapy, which is vital if clinical trials are to be performed on human patients.
X-TREAM protocol for in vitro microbeam radiation therapy at the Australian Synchrotron
Publisher: AIP Publishing
Date: 28-06-2021
DOI: 10.1063/5.0040013
Abstract: Recommendations for an experimental protocol for beam alignment/optimization and dosimetry relating to in vitro studies at the Imaging and Medical Beam Line of the Australian Synchrotron are presented. An evaluation of the protocol, based upon the consistency and reproducibility of in vitro experiments performed over several years at the Australian Synchrotron, is provided for the community.
Reference dosimetry at the Australian Synchrotron's imaging and medical beamline using free-air ionization chamber measurements and theoretical predictions of air kerma rate and half value layer
Publisher: Wiley
Date: 20-05-2013
DOI: 10.1118/1.4803675
Abstract: Novel, preclinical radiotherapy modalities are being developed at synchrotrons around the world, most notably stereotactic synchrotron radiation therapy and microbeam radiotherapy at the European Synchrotron Radiation Facility in Grenoble, France. The imaging and medical beamline (IMBL) at the Australian Synchrotron has recently become available for preclinical radiotherapy and imaging research with clinical trials, a distinct possibility in the coming years. The aim of this present study was to accurately characterize the synchrotron-generated x-ray beam for the purposes of air kerma-based absolute dosimetry. The authors used a theoretical model of the energy spectrum from the wiggler source and validated this model by comparing the transmission through copper absorbers (0.1-3.0 mm) against real measurements conducted at the beamline. The authors used a low energy free air ionization chamber (LEFAC) from the Australian Radiation Protection and Nuclear Safety Agency and a commercially available free air chamber (ADC-105) for the measurements. The dimensions of these two chambers are different from one another requiring careful consideration of correction factors. Measured and calculated half value layer (HVL) and air kerma rates differed by less than 3% for the LEFAC when the ion chamber readings were corrected for electron energy loss and ion recombination. The agreement between measured and predicted air kerma rates was less satisfactory for the ADC-105 chamber, however. The LEFAC and ADC measurements produced a first half value layer of 0.405 ± 0.015 and 0.412 ± 0.016 mm Cu, respectively, compared to the theoretical prediction of 0.427 ± 0.012 mm Cu. The theoretical model based upon a spectrum calculator derived a mean beam energy of 61.4 keV with a first half value layer of approximately 30 mm in water. The authors showed in this study their ability to verify the predicted air kerma rate and x-ray attenuation curve on the IMBL using a simple experimental method, namely, HVL measurements. The HVL measurements strongly supports the x-ray beam spectrum, which in turn has a profound effect on x-ray dosimetry.
Spatial response of synthetic microDiamond and diode detectors measured with kilovoltage synchrotron radiation
Publisher: Wiley
Date: 18-01-2018
DOI: 10.1002/MP.12733
Abstract: To map the spatial response of four solid-state radiation detectors of types commonly used for radiotherapy dosimetry. PTW model 60016 Diode P, 60017 Diode E, 60018 Diode SRS, and 60019 microDiamond detectors were radiographed using a high resolution conventional X-ray system. Their spatial response was then investigated using a 0.1 mm diameter beam of 95 keV average energy photons generated by a synchrotron. The detectors were scanned through the beam while their signal was recorded as a function of position, to map the response. These 2D response maps were created in both the end-on and side-on orientations. The results show the location and size of the active region. End-on, the active area was determined to be centrally located and within 0.2 mm of the manufacturer's specified diameter. The active areas of the 60016 Diode P, 60017 Diode E, 60018 Diode SRS detectors are uniform to within approximately 5%. The 60019 microDiamond showed local variations up to 30%. The extra-cameral signal in the microDiamond was calculated from the side-on scan to be approximately 8% of the signal from the active element. The spatial response of four solid-state detectors has been measured. The technique yielded information about the location and uniformity of the active area, and the extra-cameral signal, for the beam quality used.
Detectors for the imaging and medical beam line at the Australian Synchrotron
Publisher: IOP Publishing
Date: 27-06-2013
Child Protection in Europe: Development of an International Cross-Comparison Model to Inform National Policies and Practices
Publisher: Oxford University Press (OUP)
Date: 09-10-2014
DOI: 10.1093/BJSW/BCU109
Localized Synchrotron Irradiation of Mouse Skin Induces Persistent Systemic Genotoxic and Immune Responses.
Publisher: American Association for Cancer Research (AACR)
Date: 14-11-2017
DOI: 10.1158/0008-5472.CAN-17-1066
Abstract: The importance of nontargeted (systemic) effects of ionizing radiation is attracting increasing attention. Exploiting synchrotron radiation generated by the Imaging and Medical Beamline at the Australian Synchrotron, we studied radiation-induced nontargeted effects in C57BL/6 mice. Mice were locally irradiated with a synchrotron X-ray broad beam and a multiplanar microbeam radiotherapy beam. To assess the influence of the beam configurations and variations in peak dose and irradiated area in the response of normal tissues outside the irradiated field at 1 and 4 days after irradiation, we monitored oxidatively induced clustered DNA lesions (OCDL), DNA double-strand breaks (DSB), apoptosis, and the local and systemic immune responses. All radiation settings induced pronounced persistent systemic effects in mice, which resulted from even short exposures of a small irradiated area. OCDLs were elevated in a wide variety of unirradiated normal tissues. In out-of-field duodenum, there was a trend for elevated apoptotic cell death under most irradiation conditions however, DSBs were elevated only after exposure to lower doses. These genotoxic events were accompanied by changes in plasma concentrations of macrophage-derived cytokine, eotaxin, IL10, TIMP1, VEGF, TGFβ1, and TGFβ2, along with changes in tissues in frequencies of macrophages, neutrophils, and T lymphocytes. Overall, our findings have implications for the planning of therapeutic and diagnostic radiation treatments to reduce the risk of radiation-related adverse systemic effects. Cancer Res 77(22) 6389–99. ©2017 AACR.
Modulating Synchrotron Microbeam Radiation Therapy Doses for Preclinical Brain Cancer
Publisher: MDPI AG
Date: 14-10-2023
Impact of magnetic fields on dose measurement with small ion chambers illustrated in high‐resolution response maps
Publisher: Wiley
Date: 11-06-2019
DOI: 10.1002/MP.13591
An Evaluation of Dose Equivalence between Synchrotron Microbeam Radiation Therapy and Conventional Broadbeam Radiation Using Clonogenic and Cell Impedance Assays
Publisher: Public Library of Science (PLoS)
Date: 19-06-2014
A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron
Publisher: International Union of Crystallography (IUCr)
Date: 16-10-2015
DOI: 10.1107/S160057751501766X
Abstract: Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, s le-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 µm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses.
X-ray Phase-Contrast Computed Tomography for Soft Tissue Imaging at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron
Publisher: MDPI AG
Date: 03-04-2021
DOI: 10.3390/APP11094120
Abstract: The Imaging and Medical Beamline (IMBL) is a superconducting multipole wiggler-based beamline at the 3 GeV Australian Synchrotron operated by the Australian Nuclear Science and Technology Organisation (ANSTO). The beamline delivers hard X-rays in the 25–120 keV energy range and offers the potential for a range of biomedical X-ray applications, including radiotherapy and medical imaging experiments. One of the imaging modalities available at IMBL is propagation-based X-ray phase-contrast computed tomography (PCT). PCT produces superior results when imaging low-density materials such as soft tissue (e.g., breast mastectomies) and has the potential to be developed into a valuable medical imaging tool. We anticipate that PCT will be utilized for medical breast imaging in the near future with the advantage that it could provide better contrast than conventional X-ray absorption imaging. The unique properties of synchrotron X-ray sources such as high coherence, energy tunability, and high brightness are particularly well-suited for generating PCT data using very short exposure times on the order of less than 1 min. The coherence of synchrotron radiation allows for phase-contrast imaging with superior sensitivity to small differences in soft-tissue density. Here we also compare the results of PCT using two different detectors, as these unique source characteristics need to be complemented with a highly efficient detector. Moreover, the application of phase retrieval for PCT image reconstruction enables the use of noisier images, potentially significantly reducing the total dose received by patients during acquisition. This work is part of ongoing research into innovative tomographic methods aimed at the introduction of 3D X-ray medical imaging at the IMBL to improve the detection and diagnosis of breast cancer. Major progress in this area at the IMBL includes the characterization of a large number of mastectomy s les, both normal and cancerous, which have been scanned at clinically acceptable radiation dose levels and evaluated by expert radiologists with respect to both image quality and cancer diagnosis.
Validation of a Monte Carlo simulation for Microbeam Radiation Therapy on the Imaging and Medical Beamline at the Australian Synchrotron
Publisher: Springer Science and Business Media LLC
Date: 27-11-2019
DOI: 10.1038/S41598-019-53991-9
Abstract: Microbeam Radiation Therapy (MRT) is an emerging cancer treatment modality characterised by the use of high-intensity synchrotron-generated x-rays, spatially fractionated by a multi-slit collimator (MSC), to ablate target tumours. The implementation of an accurate treatment planning system, coupled with simulation tools that allow for independent verification of calculated dose distributions are required to ensure optimal treatment outcomes via reliable dose delivery. In this article we present data from the first Geant4 Monte Carlo radiation transport model of the Imaging and Medical Beamline at the Australian Synchrotron. We have developed the model for use as an independent verification tool for experiments in one of three MRT delivery rooms and therefore compare simulation results with equivalent experimental data. The normalised x-ray spectra produced by the Geant4 model and a previously validated analytical model, SPEC, showed very good agreement using wiggler magnetic field strengths of 2 and 3 T. However, the validity of absolute photon flux at the plane of the Phase Space File (PSF) for a fixed number of simulated electrons was unable to be established. This work shows a possible limitation of the G 4 SynchrotronRadiation process to model synchrotron radiation when using a variable magnetic field. To account for this limitation, experimentally derived normalisation factors for each wiggler field strength determined under reference conditions were implemented. Experimentally measured broadbeam and microbeam dose distributions within a Gammex RMI457 Solid Water ® phantom were compared to simulated distributions generated by the Geant4 model. Simulated and measured broadbeam dose distributions agreed within 3% for all investigated configurations and measured depths. Agreement between the simulated and measured microbeam dose distributions agreed within 5% for all investigated configurations and measured depths.
Synchrotron radiation external beam rotational radiotherapy of breast cancer: proof of principle.
Publisher: International Union of Crystallography (IUCr)
Date: 25-04-2018
DOI: 10.1107/S1600577518003788
Abstract: The principle of rotational summation of the absorbed dose for breast cancer treatment with orthovoltage X-ray beams was proposed by J. Boone in 2012. Here, use of X-ray synchrotron radiation for image guided external beam rotational radiotherapy treatment of breast cancer is proposed. Tumor irradiation occurs with the patient in the prone position hosted on a rotating bed, with her breast hanging from a hole in the bed, which rotates around a vertical axis passing through the tumor site. Horizontal collimation of the X-ray beam provides for whole breast or partial breast irradiation, while vertical translation of the bed and successive rotations allow for irradiation of the full tumor volume, with dose rates which permit also hypofractionated treatments. In this work, which follows a previous preliminary report, results are shown of a full series of measurements on polyethylene and acrylic cylindrical phantoms carried out at the Australian Synchrotron, confirmed by Geant4 Monte Carlo simulations, intended to demonstrate the proof of principle of the technique. Dose measurements were carried out with calibrated ion chambers, radiochromic films and thermoluminescence dosimeters. The photon energy investigated was 60 keV. Image guidance may occur with the transmitted beam for contrast-enhanced breast computed tomography. For a horizontal beam collimation of 1.5 cm and rotation around the central axis of a 14 cm-diameter polyethylene phantom, a periphery-to-center dose ratio of 14% was measured. The simulations showed that under the same conditions the dose ratio decreases with increasing photon energy down to 10% at 175 keV. These values are comparable with those achievable with conventional megavoltage radiotherapy of breast cancer with a medical linear accelerator. Dose painting was demonstrated with two off-center `cancer foci' with 1.3 Gy and 0.6 Gy target doses. The use of a radiosensitizing agent for dose enhancement is foreseen.
A Functional Immune System Is Required for the Systemic Genotoxic Effects of Localized Irradiation.
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.IJROBP.2018.11.066
Abstract: Nontargeted effects of ionizing radiation, by which unirradiated cells and tissues are also damaged, are a relatively new paradigm in radiobiology. We recently reported radiation-induced abscopal effects (RIAEs) in normal tissues namely, DNA damage, apoptosis, and activation of the local and systemic immune responses in C57BL6/J mice after irradiation of a small region of the body. High-dose-rate, synchrotron-generated broad beam or multiplanar x-ray microbeam radiation therapy was used with various field sizes and doses. This study explores components of the immune system involved in the generation of these abscopal effects. The following mice with various immune deficiencies were irradiated with the microbeam radiation therapy beam: (1) SCID/IL2γR Wild-type mice accumulated double-strand breaks, oxidatively induced clustered DNA lesions, and apoptosis, enforcing our RIAE model. However, these effects were completely or partially abrogated in mice with immune disruption, highlighting the pivotal role of the immune system in propagation of systemic genotoxic effects after localized irradiation. These results underline the importance of not only delineating the best strategies for tumor control but also mitigating systemic radiation toxicity.
Toolbox for advanced X-ray image processing
Publisher: SPIE
Date: 08-09-2011
DOI: 10.1117/12.893252
In situ study of plastic deformation in a Mg-Ce alloy using polychromatic micro X-ray diffraction
Publisher: Elsevier BV
Date: 07-2012
In-line phase-contrast X-ray imaging and tomography for materials science
Publisher: MDPI AG
Date: 24-05-2012
DOI: 10.3390/MA5050937
X-Tream dosimetry of highly brilliant X-ray microbeams in the MRT hutch of the Australian Synchrotron
Publisher: Elsevier BV
Date: 2016
Related Organisations
Commonwealth Scientific And Industrial Research Organisation
Location: Australia
Related Funding Activities
Discovery Projects - Grant ID: DP200100727
Start Date: 07-2020
End Date: 12-2023
Amount: $361,640.00
Funder: Australian Research Council
View Funded ActivityIndustrial Transformation Training Centres - Grant ID: IC180100008
Start Date: 07-2019
End Date: 06-2025
Amount: $3,981,223.00
Funder: Australian Research Council
View Funded Activity