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Experimental Investigation Of The 100 Kev X-Ray Dose Response Of The High-Temperature Thermoluminescence In Lif: Mg, Ti (Tld-100): Theoretical Interpretation Using The Unified Interaction Model, Jayde Livingstone, Y Horowitz, L Oster, H Datz, Michael Lerch, Anatoly Rosenfeld, A Horowitz
Experimental Investigation Of The 100 Kev X-Ray Dose Response Of The High-Temperature Thermoluminescence In Lif: Mg, Ti (Tld-100): Theoretical Interpretation Using The Unified Interaction Model, Jayde Livingstone, Y Horowitz, L Oster, H Datz, Michael Lerch, Anatoly Rosenfeld, A Horowitz
Michael L.F. Lerch
The dose response of LiF:Mg,Ti (TLD-100) chips was measured from 1 to 50 000 Gy using 100 keV X rays at the European Synchroton Radiation Facility. Glow curves were deconvoluted into component glow peaks using a computerised glow curve deconvolution (CGCD) code based on first-order kinetics. The normalised dose response, f(D), of glow peaks 4 and 5 and 5b (the major components of composite peak 5), as well as peaks 7 and 8 (two of the major components of the high-temperature thermoluminescence (HTTL) at high levels of dose) was separately determined and theoretically interpreted using the unified interaction model (UNIM). …
A Silicon Strip Detector Dose Magnifying Glass For Imrt Dosimetry, J.H.D Wong, Martin Carolan, Michael Lerch, Marco Petasecca, Sutinder Khanna, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
A Silicon Strip Detector Dose Magnifying Glass For Imrt Dosimetry, J.H.D Wong, Martin Carolan, Michael Lerch, Marco Petasecca, Sutinder Khanna, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
Michael L.F. Lerch
Purpose: Intensity modulated radiation therapy (IMRT) allows the delivery of escalated radiation dose to tumor while sparing adjacent critical organs. In doing so, IMRT plans tend to incorporate steep dose gradients at interfaces between the target and the organs at risk. Current quality assurance (QA) verification tools such as 2D diode arrays, are limited by their spatial resolution and conventional films are nonreal time. In this article, the authors describe a novel silicon strip detector (CMRP DMG) of high spatial resolution (200 μm) suitable for measuring the high dose gradients in an IMRT delivery. Methods: A full characterization of the …
From Hep To Medical Radiation Dosimetry - The Silicon Strip Detector Dose Magnifying Glass, J.H.D Wong, Dean Cutajar, Michael Lerch, Marco Petasecca, T Knittel, Martin Carolan, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
From Hep To Medical Radiation Dosimetry - The Silicon Strip Detector Dose Magnifying Glass, J.H.D Wong, Dean Cutajar, Michael Lerch, Marco Petasecca, T Knittel, Martin Carolan, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
Michael L.F. Lerch
High energy physics (HEP) experiments and research gave rise to the development of high spatial resolution tracking vertex detectors and the accompanying data acquisition systems (DAQ) capable of high temporal resolution measurements. The technology translation from HEP to the day to day medical radiation dosimetry is gradual but certain. This paper discusses the design and development of a high spatial resolution (0.2 mm pitch) silicon strip detector referred to as the Dose Magnifying Glass designed and prototyped by the Centre for Medical Radiation Physics (CMRP), University of Wollongong. The DMG has 128 phosphor implanted n+ strips on a p-type silicon …
Solid State Diode - Ionization Chamber Method For Measuring Out-Of-Field Neutron Dose In Proton Therapy, Amy Ziebell, B Clasie, Andrew Wroe, Reinhard Schulte, Mark Reinhard, Stephen Dowdell, Michael Lerch, Marco Petasecca, V Perevertaylo, Oleg Zinets, Igor Anokhin, Anatoly Rosenfeld
Solid State Diode - Ionization Chamber Method For Measuring Out-Of-Field Neutron Dose In Proton Therapy, Amy Ziebell, B Clasie, Andrew Wroe, Reinhard Schulte, Mark Reinhard, Stephen Dowdell, Michael Lerch, Marco Petasecca, V Perevertaylo, Oleg Zinets, Igor Anokhin, Anatoly Rosenfeld
Michael L.F. Lerch
In proton therapy neutrons are introduced to out-of-field regions inside the patient. Clinicians would like to know the absorbed dose being deposited by neutrons separately to that from protons, so as to be able to directly apply their own dose equivalent weighting factors based on their opinion of the biological risk posed by neutrons in this region. The purpose of this study is to investigate a novel approach to experimentally separating the proton and neutron contributions to the absorbed dose in out-of-field regions. The method pairs specially designed silicon PIN diodes with a standard clinical ionization chamber. The sensitivity of …
In Vivo Verification Of Superficial Dose For Head And Neck Treatments Using Intensity-Modulated Techniques, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Li Zhang, Zhi-Chun He, X. Allen Li, Ian Kwan, Michael Lerch, Dean Cutajar, Peter Metcalfe, Anatoly Rosenfeld
In Vivo Verification Of Superficial Dose For Head And Neck Treatments Using Intensity-Modulated Techniques, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Li Zhang, Zhi-Chun He, X. Allen Li, Ian Kwan, Michael Lerch, Dean Cutajar, Peter Metcalfe, Anatoly Rosenfeld
Michael L.F. Lerch
Skin dose is one of the key issues for clinical dosimetry in radiation therapy. Currently planning computer systems are unable to accurately predict dose in the buildup region, leaving ambiguity as to the dose levels actually received by the patient’s skin during radiotherapy. This is one of the prime reasons why in vivo measurements are necessary to estimate the dose in the buildup region. A newly developed metal-oxide-semiconductor-field-effect-transistor (MOSFET) detector designed specifically for dose measurements in rapidly changing dose gradients was introduced for accurate in vivo skin dosimetry. The feasibility of this detector for skin dose measurements was verified in …
Measurement Of Rectal Dose During Hdr Brachytherapy Using The New Moskin Dosimeter, Ian Kwan, Andrew Howie, Michael Lerch, Bong Soo Lee, Yaw Sinn Chin, Joseph Bucci, V Perevertaylo, Anatoly Rosenfeld
Measurement Of Rectal Dose During Hdr Brachytherapy Using The New Moskin Dosimeter, Ian Kwan, Andrew Howie, Michael Lerch, Bong Soo Lee, Yaw Sinn Chin, Joseph Bucci, V Perevertaylo, Anatoly Rosenfeld
Michael L.F. Lerch
In HDR prostate brachytherapy, post-treatment complications occur due to overdosing the rectum wall and urethra. An area of concern regarding treatment is related to how the rectal wall dose is calculated using treatment planning systems. Treatment planning systems can calculate the dose delivered to the rectal wall, assuming that the rectum is filled with water equivalent material. This assumption is not always correct, as the rectum is emptied before treatment begins. The aim of this research is to quantify the difference in the dose measured in an ‘empty’ rectal phantom, and in a rectal phantom filled with water equivalent material. …
Verification Of The Plan Dosimetry For High Dose Rate Brachytherapy Using Metal-Oxide-Semiconductor Field Effect Transistor Detectors, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Jie Lu, Michael Lerch, Dean Cutajar, Anatoly Rosenfeld
Verification Of The Plan Dosimetry For High Dose Rate Brachytherapy Using Metal-Oxide-Semiconductor Field Effect Transistor Detectors, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Jie Lu, Michael Lerch, Dean Cutajar, Anatoly Rosenfeld
Michael L.F. Lerch
The feasibility of a recently designed metal–oxide–semiconductor field effect transistor (MOSFET) dosimetry system for dose verification of high dose rate (HDR) brachytherapy treatment planning was investigated. MOSFET detectors were calibrated with a 0.6 cm3 NE-2571 Farmer-type ionization chamber in water. Key characteristics of the MOSFET detectors, such as the energy dependence, that will affect phantom measurements with HDR 192Ir sources were measured. The MOSFET detector was then applied to verify the dosimetric accuracy of HDR brachytherapy treatments in a custom-made water phantom. Three MOSFET detectors were calibrated independently, with the calibration factors ranging from 0.187 to 0.215 cGy∕mV. A distance …
Independent Quality Assurance Of A Helical Tomotherapy Machine Using The Dose Magnifying Glass, Jeannie Wong, Nick Hardcastle, Wolfgang Tome, A Bayliss, R Tolakanahalli, Michael Lerch, Marco Petasecca, Martin Carolan, Peter Metcalfe, Anatoly Rosenfeld
Independent Quality Assurance Of A Helical Tomotherapy Machine Using The Dose Magnifying Glass, Jeannie Wong, Nick Hardcastle, Wolfgang Tome, A Bayliss, R Tolakanahalli, Michael Lerch, Marco Petasecca, Martin Carolan, Peter Metcalfe, Anatoly Rosenfeld
Michael L.F. Lerch
Purpose: Helical tomotherapy is a complex delivery technique, integrating CT image guidance and intensity modulated radiotherapy in a single system. The integration of the CT detector ring on the gantry not only allows patient position verification but is also often used to perform various QA procedures. This convenience lacks the rigor of a machine-independent QA process. Methods: In this article, a Si strip detector, known as the Dose Magnifying Glass (DMG), was used to perform machine-independent QA measurements of the multileaf collimator alignment, leaf open time threshold, and leaf fluence output factor (LFOF). Results: The DMG measurements showed good agreements …
Verification Of The Plan Dosimetry For High Dose Rate Brachytherapy Using Metal-Oxide-Semiconductor Field Effect Transistor Detectors, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Jie Lu, Michael Lerch, Dean Cutajar, Anatoly Rosenfeld
Verification Of The Plan Dosimetry For High Dose Rate Brachytherapy Using Metal-Oxide-Semiconductor Field Effect Transistor Detectors, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Jie Lu, Michael Lerch, Dean Cutajar, Anatoly Rosenfeld
Dean Cutajar
The feasibility of a recently designed metal–oxide–semiconductor field effect transistor (MOSFET) dosimetry system for dose verification of high dose rate (HDR) brachytherapy treatment planning was investigated. MOSFET detectors were calibrated with a 0.6 cm3 NE-2571 Farmer-type ionization chamber in water. Key characteristics of the MOSFET detectors, such as the energy dependence, that will affect phantom measurements with HDR 192Ir sources were measured. The MOSFET detector was then applied to verify the dosimetric accuracy of HDR brachytherapy treatments in a custom-made water phantom. Three MOSFET detectors were calibrated independently, with the calibration factors ranging from 0.187 to 0.215 cGy∕mV. A distance …
In Vivo Verification Of Superficial Dose For Head And Neck Treatments Using Intensity-Modulated Techniques, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Li Zhang, Zhi-Chun He, X. Allen Li, Ian Kwan, Michael Lerch, Dean Cutajar, Peter Metcalfe, Anatoly Rosenfeld
In Vivo Verification Of Superficial Dose For Head And Neck Treatments Using Intensity-Modulated Techniques, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Li Zhang, Zhi-Chun He, X. Allen Li, Ian Kwan, Michael Lerch, Dean Cutajar, Peter Metcalfe, Anatoly Rosenfeld
Dean Cutajar
Skin dose is one of the key issues for clinical dosimetry in radiation therapy. Currently planning computer systems are unable to accurately predict dose in the buildup region, leaving ambiguity as to the dose levels actually received by the patient’s skin during radiotherapy. This is one of the prime reasons why in vivo measurements are necessary to estimate the dose in the buildup region. A newly developed metal-oxide-semiconductor-field-effect-transistor (MOSFET) detector designed specifically for dose measurements in rapidly changing dose gradients was introduced for accurate in vivo skin dosimetry. The feasibility of this detector for skin dose measurements was verified in …
From Hep To Medical Radiation Dosimetry - The Silicon Strip Detector Dose Magnifying Glass, J.H.D Wong, Dean Cutajar, Michael Lerch, Marco Petasecca, T Knittel, Martin Carolan, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
From Hep To Medical Radiation Dosimetry - The Silicon Strip Detector Dose Magnifying Glass, J.H.D Wong, Dean Cutajar, Michael Lerch, Marco Petasecca, T Knittel, Martin Carolan, V Perevertaylo, Peter Metcalfe, Anatoly Rosenfeld
Dean Cutajar
High energy physics (HEP) experiments and research gave rise to the development of high spatial resolution tracking vertex detectors and the accompanying data acquisition systems (DAQ) capable of high temporal resolution measurements. The technology translation from HEP to the day to day medical radiation dosimetry is gradual but certain. This paper discusses the design and development of a high spatial resolution (0.2 mm pitch) silicon strip detector referred to as the Dose Magnifying Glass designed and prototyped by the Centre for Medical Radiation Physics (CMRP), University of Wollongong. The DMG has 128 phosphor implanted n+ strips on a p-type silicon …