1
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Kairn T, Talkhani S, Charles PH, Chua B, Lin CY, Livingstone AG, Maxwell SK, Poroa T, Simpson-Page E, Spelleken E, Vo M, Crowe SB. Determining tolerance levels for quality assurance of 3D printed bolus for modulated arc radiotherapy of the nose. Phys Eng Sci Med 2021; 44:1187-1199. [PMID: 34529247 DOI: 10.1007/s13246-021-01054-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/31/2021] [Indexed: 10/20/2022]
Abstract
Given the existing literature on the subject, there is obviously a need for specific advice on quality assurance (QA) tolerances for departments using or implementing 3D printed bolus for radiotherapy treatments. With a view to providing initial suggested QA tolerances for 3D printed bolus, this study evaluated the dosimetric effects of changes in bolus geometry and density, for a particularly common and challenging clinical situation: specifically, volumetric modulated arc therapy (VMAT) treatment of the nose. Film-based dose verification measurements demonstrated that both the AAA and the AXB algorithms used by the Varian Eclipse treatment planning system (Varian Medical Systems, Palo Alto, USA) were capable of providing sufficiently accurate dose calculations to allow this planning system to be used to evaluate the effects of bolus errors on dose distributions from VMAT treatments of the nose. Thereafter, the AAA and AXB algorithms were used to calculate the dosimetric effects of applying a range of simulated errors to the design of a virtual bolus, to identify QA tolerances that could be used to avoid clinically significant effects from common printing errors. Results were generally consistent, whether the treatment target was superficial and treated with counter-rotating coplanar arcs or more-penetrating and treated with noncoplanar arcs, and whether the dose was calculated using the AAA algorithm or the AXB algorithm. The results of this study suggest the following QA tolerances are advisable, when 3D printed bolus is fabricated for use in photon VMAT treatments of the nose: bolus relative electron density variation within [Formula: see text] (although an action level at [Formula: see text] may be permissible); bolus thickness variation within [Formula: see text] mm (or 0.5 mm variation on opposite sides); and air gap between bolus and skin [Formula: see text] mm. These tolerances should be investigated for validity with respect to other treatment modalities and anatomical sites. This study provides a set of baselines for future comparisons and a useful method for identifying additional or alternative 3D printed bolus QA tolerances.
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Affiliation(s)
- T Kairn
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia. .,Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, QLD, Australia. .,School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia. .,School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia.
| | - S Talkhani
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia
| | - P H Charles
- Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, QLD, Australia.,School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia
| | - B Chua
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - C Y Lin
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - A G Livingstone
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - S K Maxwell
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - T Poroa
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - E Simpson-Page
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - E Spelleken
- GenesisCare Rockhampton, Rockhampton Hospital, Rockhampton, QLD, Australia
| | - M Vo
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - S B Crowe
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, QLD, Australia.,School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia
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2
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Spelleken E, Hellyer J, Crowe S, Kairn T. PO-1579 Dosimetric effects of small fields and air gaps when using 3D printed bolus. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)08030-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Kairn T, Maxwell SK, Trapp JV, Crowe SB. ASSESSMENT OF INTEGRITY AND LEAD-EQUIVALENCE OF SHIELDED GARMENTS USING TWO-DIMENSIONAL X-RAY IMAGES FROM A COMPUTED TOMOGRAPHY SCANNER. Radiat Prot Dosimetry 2021; 193:155-164. [PMID: 33822208 DOI: 10.1093/rpd/ncab037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/13/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Shielded garments are widely recommended for occupational radiation protection in diagnostic and interventional radiology. This study investigated a novel method for efficiently verifying shielded garment integrity while simultaneously acquiring data for lead-equivalence measurements, using two-dimensional topogram images from computed tomography (CT) scanners. This method was tested against more-conventional measurements with superficial and orthovoltage radiotherapy treatment beams, for 12 shielded garments containing 3 different lead-free shielding materials. Despite some energy-dependent results, all shielded garments approximately achieved their specified lead-equivalence for the energy range expected during clinical use for fluoroscopy procedures, except for three shielded skirts that required two layers of material to be overlapped at the front. All lead-equivalence measurements from CT topograms agreed with or conservatively underestimated the kV narrow-beam results. This method is potentially useful for independently assessing the shielding properties of new shielded garments and performing annual checks for damage or degradation of existing shielded garments.
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Affiliation(s)
- T Kairn
- Cancer Care Services, Royal Brisbane and Women's Hospital, Butterfield St, Herston 4029, Qld, Australia
- School of Chemistry and Physics, Queensland University of Technology, 2 George St, Brisbane 4000, Qld, Australia
- Herston Biofabrication Institute, Metro North Hospital and Health Service, Butterfield St, Herston 4029, Qld, Australia
- School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - S K Maxwell
- Cancer Care Services, Royal Brisbane and Women's Hospital, Butterfield St, Herston 4029, Qld, Australia
| | - J V Trapp
- School of Chemistry and Physics, Queensland University of Technology, 2 George St, Brisbane 4000, Qld, Australia
| | - S B Crowe
- Cancer Care Services, Royal Brisbane and Women's Hospital, Butterfield St, Herston 4029, Qld, Australia
- School of Chemistry and Physics, Queensland University of Technology, 2 George St, Brisbane 4000, Qld, Australia
- Herston Biofabrication Institute, Metro North Hospital and Health Service, Butterfield St, Herston 4029, Qld, Australia
- School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Qld 4072, Australia
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4
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Aland T, Jarema T, Trapp JV, Kairn T. Patient-specific quality assurance on a Varian Halcyon linear accelerator using a PTW Octavius 4D device. Phys Eng Sci Med 2021; 44:565-572. [PMID: 33704691 DOI: 10.1007/s13246-021-00986-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/25/2021] [Indexed: 11/25/2022]
Abstract
This study investigates and validates the use of the Octavius 4D system for patient specific quality assurance on Halcyon, which is capable of rotating at 4 revolutions per minute (RPM). A commercially available PTW Octavius 4D system was used for this study which had a maximum rotation speed of 3 RPM. Initial validation included testing the accuracy of the inclinometer, percent depth doses (PDD), output factors, and dose profiles for selected static square fields. The same static fields were also subject to a gamma comparison with the TPS. This was followed by an evaluation of twelve clinical treatment plans and seven non-clinical plans with varying gantry rotation speeds. All testing was completed using detector array measurement times of 200 ms and 100 ms. Inclinometer accuracy was within 0.3° of actual gantry angle. Output factors varied less than 0.6%, PDD differences were no greater than 1.4%, and dose profile differences were less than 2.2%. Gamma pass rates for the static fields were 96.7% (2%/2mm) and 99.7% (3%/3mm). A prototype control unit, which had a maximum rotation speed of 4 RPM was also used to test the clinical and non-clinical plans. For the clinical plans, the mean gamma pass rates (2%/2mm) were 86.1% and 88.1% for the commercial unit and prototype unit respectively. Results using a measurement time of 200 ms were superior to those using 100 ms. For Halcyon deliveries greater than 3 RPM, worst case gamma results for the commercial unit were 28.6% compared to 98.5% using the prototype unit. Accurate patient specific quality assurance results can be obtained using the Octavius 4D system with a Halcyon linac, provided that the system measurement time is kept at 200 ms and the rotation speed of Halycon does not exceed 3 RPM. For higher RPM deliveries, an Octavius 4D unit with 4 RPM rotation capability is recommended.
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Affiliation(s)
- T Aland
- Icon Group, 22 Cordelia Street, South Brisbane, QLD, 4101, Australia.
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD, 4000, Australia.
| | - T Jarema
- Icon Group, 22 Cordelia Street, South Brisbane, QLD, 4101, Australia
| | - J V Trapp
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD, 4000, Australia
| | - T Kairn
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD, 4000, Australia
- Cancer Care Services, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
- School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, QLD, 4072, Australia
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5
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Kairn T, Lathouras M, Sylvander S, Crowe S. PO-1421: Investigating dose calculation accuracy around gas-filled tissue expanders using 3D-printed phantoms. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01439-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Stephens H, Deans C, Schlect D, Kairn T. Development of a method for treating lower-eyelid carcinomas using superficial high dose rate brachytherapy. Phys Eng Sci Med 2020; 43:1317-1325. [PMID: 33123861 DOI: 10.1007/s13246-020-00935-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 10/03/2020] [Indexed: 11/26/2022]
Abstract
In this study, a method was developed for delivering high dose rate (HDR) brachytherapy treatments to basal cell carcinomas (BCCs) as well as squamous cell carcinomas (SCCs) of the lower eyelid via superficial catheters. Clinically-realistic BCC/SCC treatment areas were marked in the lower-eyelid region on a head phantom and several arrangements of catheters and bolus were trialled for treating those areas. The use of one or two catheters of different types was evaluated, and sources of dosimetric uncertainty (including air gaps) were evaluated and mitigated. Test treatments were planned for delivery with an iridium-192 source, using the Oncentra Brachy treatment planning system (Elekta AB, Stockholm, Sweden). Dose distributions were evaluated using radiochromic film. The proposed method was shown to be clinically viable, for using superficial HDR brachytherapy to overcome anatomical difficulties and create non-surgical treatments for BCC and SCC of the lower eyelid.
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Affiliation(s)
- H Stephens
- Chermside Medical Complex, Ground Floor, 956 Gympie Road, Chermside, Qld, 4032, Australia.
- School of Physical Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia.
| | - C Deans
- Chermside Medical Complex, Ground Floor, 956 Gympie Road, Chermside, Qld, 4032, Australia
- Icon Integrated Cancer Centre, 9 McLennan Ct, North Lakes, Qld, 4509, Australia
| | - D Schlect
- Chermside Medical Complex, Ground Floor, 956 Gympie Road, Chermside, Qld, 4032, Australia
| | - T Kairn
- Cancer Care Services, Royal Brisbane and Women's Hospital, Herston, Qld, 4029, Australia
- Science and Engineering Faculty, Queensland University of Technology, Gardens Point, Qld, 4001, Australia
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7
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Livingstone AG, Crowe SB, Sylvander S, Kairn T. Clinical implementation of a Monte Carlo based independent TPS dose checking system. Phys Eng Sci Med 2020; 43:1113-1123. [PMID: 32780274 DOI: 10.1007/s13246-020-00907-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/20/2020] [Indexed: 11/26/2022]
Abstract
The increase in complexity of treatment plans over time through modalities such as intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) has often not been met with an increase in capability of the secondary dose calculation checking systems typically used to verify the treatment planning system. Monte Carlo (MC) codes such as EGSnrc have become easily available and are capable of performing calculations of highly complex radiotherapy treatments. This educational note demonstrates a method for implementing and using a fully automated system for performing and analysing full MC calculations of conformal, IMRT and VMAT radiotherapy plans. Example calculations were based on BEAMnrc/DOSXYZnrc and are performed automatically after either uploading exported plan DICOM data through a Python-based web interface, or exporting DICOM data to a monitored network location. This note demonstrates how completed MC calculations can then be analysed using an automatically generated dose point comparison report, or easily re-imported back into the treatment planning system. Agreement between the TPS and MC calculation was an improvement on agreement between RadCalc and the TPS, with differences ranging from 1.2 to 5.5% between RadCalc and the treatment planning system (TPS), and 0.1-1.7% between MC and TPS. Comparison of the dose-volume histogram (DVH) parameters [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the example VMAT plans showed agreement for the mean planning target volume dose within [Formula: see text], [Formula: see text] and [Formula: see text] generally within [Formula: see text] with the exception of a brain case, and [Formula: see text] within [Formula: see text]. Overall, this note provides a demonstration of a system that has been integrated well into existing clinical workflow, and has been shown to be a valuable additional tool in the secondary checking of treatment plan calculations.
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Affiliation(s)
- A G Livingstone
- Royal Brisbane and Women's Hospital, Herston, QLD, Australia.
| | - S B Crowe
- Royal Brisbane and Women's Hospital, Herston, QLD, Australia
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
| | - S Sylvander
- Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - T Kairn
- Royal Brisbane and Women's Hospital, Herston, QLD, Australia
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
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8
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Maxwell SK, Charles PH, Cassim N, Kairn T, Crowe SB. Assessing the fit of 3D printed bolus from CT, optical scanner and photogrammetry methods. Phys Eng Sci Med 2020; 43:601-607. [PMID: 32524442 DOI: 10.1007/s13246-020-00861-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 03/17/2020] [Indexed: 11/30/2022]
Abstract
Bolus plays an important role in the radiation therapy of superficial lesions and the application of 3D printing to its design can improve fit and dosimetry. This study quantitatively compares the fits of boluses designed from different imaging modalities. A head phantom was imaged using three systems: a CT simulator, a 3D optical scanner, and an interchangeable lens camera. Nose boluses were designed and 3D printed from each modality. A 3D printed phantom with air gaps of known thicknesses was used to calibrate mean HU to measure air gaps of unknown thickness and assess the fit of each bolus on the head phantom. The bolus created from the optical scanner data resulted in the best fit, with a mean air gap of 0.16 mm. Smoothing of the CT bolus resulted in a more clinically suitable model, comparable to that from the optical scanner method. The bolus produced from the photogrammetry method resulted in air gaps larger than 1 mm in thickness. The use of optical scanner and photogrammetry models have many advantages over the conventional bolus-from-CT method, however workflow should be refined to ensure accuracy if implemented clinically.
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Affiliation(s)
- S K Maxwell
- Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.
| | - P H Charles
- Herston Biofabrication Institute, Brisbane, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| | - N Cassim
- Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - T Kairn
- Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| | - S B Crowe
- Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
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9
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Smith ST, Boase NRB, Masters KS, Hosokawa K, Asena A, Crowe SB, Kairn T, Trapp JV. A very low diffusion Fricke gel dosimeter with functionalised xylenol orange-PVA (XOPVA). Phys Med Biol 2019; 64:205017. [PMID: 31505477 DOI: 10.1088/1361-6560/ab430c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A gel dosimeter has been developed utilising a recently reported system for reducing Fe3+ diffusion in a Fricke gel dosimeter which chelates xylenol orange to the gelling agent poly(vinyl alcohol) (PVA). Formulations were investigated using both gelatin and PVA as the gelling agent, along with the inclusion of glyoxal. The resulting gel had an optical density dose response of 0.0031 Gy-1, an auto-oxidation rate of 0.000 23 h-1, and a diffusion rate of 0.132 mm2 h-1 which is a significant improvement over previously reported gelatin based Fricke gel dosimeters. The gel was also shown to be energy and dose-rate independent and could be reused after irradiation. Thus, this gel dosimeter has the potential to provide a safe and practical solution to three dimensional radiation dosimetry in the medical environment.
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Affiliation(s)
- S T Smith
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia
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10
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Kairn T, Wilks R, Yu L, Crowe S. EP-1763 Monitoring total skin electron therapy using optically stimulated luminescence dosimeters. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)32183-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Kairn T, Ikeda Y, West M, Schlect D, Crowe S. EP-1855 Retrospective review of brain dose from cranial stereotactic radiosurgery treatments of metastases. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)32275-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Kairn T, Crowe SB. Application of retrospective data analysis to clinical protocol design: can the potential benefits of breath-hold techniques for breast radiotherapy be assessed without testing on patients? Australas Phys Eng Sci Med 2019; 42:227-233. [DOI: 10.1007/s13246-019-00725-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/12/2019] [Indexed: 12/25/2022]
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13
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Kakakhel MB, Jirasek A, Johnston H, Kairn T, Trapp JV. Improving the quality of reconstructed X-ray CT images of polymer gel dosimeters: zero-scan coupled with adaptive mean filtering. Australas Phys Eng Sci Med 2017; 40:159-165. [PMID: 28168587 DOI: 10.1007/s13246-017-0523-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 01/12/2017] [Indexed: 11/25/2022]
Abstract
This study evaluated the feasibility of combining the 'zero-scan' (ZS) X-ray computed tomography (CT) based polymer gel dosimeter (PGD) readout with adaptive mean (AM) filtering for improving the signal to noise ratio (SNR), and to compare these results with available average scan (AS) X-ray CT readout techniques. NIPAM PGD were manufactured, irradiated with 6 MV photons, CT imaged and processed in Matlab. AM filter for two iterations, with 3 × 3 and 5 × 5 pixels (kernel size), was used in two scenarios (a) the CT images were subjected to AM filtering (pre-processing) and these were further employed to generate AS and ZS gel images, and (b) the AS and ZS images were first reconstructed from the CT images and then AM filtering was carried out (post-processing). SNR was computed in an ROI of 30 × 30 for different pre and post processing cases. Results showed that the ZS technique combined with AM filtering resulted in improved SNR. Using the previously-recommended 25 images for reconstruction the ZS pre-processed protocol can give an increase of 44% and 80% in SNR for 3 × 3 and 5 × 5 kernel sizes respectively. However, post processing using both techniques and filter sizes introduced blur and a reduction in the spatial resolution. Based on this work, it is possible to recommend that the ZS method may be combined with pre-processed AM filtering using appropriate kernel size, to produce a large increase in the SNR of the reconstructed PGD images.
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Affiliation(s)
- M B Kakakhel
- Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences, Nilore, 45450, Islamabad, Pakistan
| | - A Jirasek
- I.K. Barber School of Arts and Science, University of British Columbia, Okanagan Campus, Vancouver, BC, Canada
| | - H Johnston
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - T Kairn
- Genesis Cancer Care Queensland, Brisbane, QLD, Australia.
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia.
| | - J V Trapp
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
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14
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Smith ST, Masters KS, Hosokawa K, Blinco JP, Crowe SB, Kairn T, Trapp JV. Technical Note: Preliminary investigations into the use of a functionalised polymer to reduce diffusion in Fricke gel dosimeters. Med Phys 2016; 42:6798-803. [PMID: 26632037 DOI: 10.1118/1.4934827] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE A modification of the existing PVA-FX hydrogel has been made to investigate the use of a functionalised polymer in a Fricke gel dosimetry system to decrease Fe(3+) diffusion. METHODS The chelating agent, xylenol orange, was chemically bonded to the gelling agent, polyvinyl alcohol (PVA) to create xylenol orange functionalised PVA (XO-PVA). A gel was created from the XO-PVA (20% w/v) with ferrous sulfate (0.4 mM) and sulfuric acid (50 mM). RESULTS This resulted in an optical density dose sensitivity of 0.014 Gy(-1), an auto-oxidation rate of 0.0005 h(-1), and a diffusion rate of 0.129 mm(2) h(-1); an 8% reduction compared to the original PVA-FX gel, which in practical terms adds approximately 1 h to the time span between irradiation and accurate read-out. CONCLUSIONS Because this initial method of chemically bonding xylenol orange to polyvinyl alcohol has inherently low conversion, the improvement on existing gel systems is minimal when compared to the drawbacks. More efficient methods of functionalising polyvinyl alcohol with xylenol orange must be developed for this system to gain clinical relevance.
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Affiliation(s)
- S T Smith
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia
| | - K-S Masters
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia
| | - K Hosokawa
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia
| | - J P Blinco
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia
| | - S B Crowe
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia and Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane 4006, Australia
| | - T Kairn
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia and Genesis Cancer Care Queensland, Brisbane 4066, Australia
| | - J V Trapp
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, Australia
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15
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Kairn T, Asena A, Charles PH, Hill B, Langton CM, Middlebrook ND, Moylan R, Trapp JV. Field size consistency of nominally matched linacs. Australas Phys Eng Sci Med 2015; 38:289-97. [DOI: 10.1007/s13246-015-0349-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 05/15/2015] [Indexed: 11/29/2022]
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16
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Crowe SB, Kairn T, Middlebrook N, Sutherland B, Hill B, Kenny J, Langton CM, Trapp JV. Examination of the properties of IMRT and VMAT beams and evaluation against pre-treatment quality assurance results. Phys Med Biol 2015; 60:2587-601. [DOI: 10.1088/0031-9155/60/6/2587] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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17
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Asena A, Kairn T, Crowe SB, Trapp JV. Establishing the impact of temporary tissue expanders on electron and photon beam dose distributions. Phys Med 2015; 31:281-5. [PMID: 25693908 DOI: 10.1016/j.ejmp.2015.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 01/16/2015] [Accepted: 01/19/2015] [Indexed: 10/24/2022] Open
Abstract
PURPOSE This study investigates the effects of temporary tissue expanders (TTEs) on the dose distributions in breast cancer radiotherapy treatments under a variety of conditions. METHODS Using EBT2 radiochromic film, both electron and photon beam dose distribution measurements were made for different phantoms, and beam geometries. This was done to establish a more comprehensive understanding of the implant's perturbation effects under a wider variety of conditions. RESULTS The magnetic disk present in a tissue expander causes a dose reduction of approximately 20% in a photon tangent treatment and 56% in electron boost fields immediately downstream of the implant. The effects of the silicon elastomer are also much more apparent in an electron beam than a photon beam. CONCLUSIONS Evidently, each component of the TTE attenuates the radiation beam to different degrees. This study has demonstrated that the accuracy of photon and electron treatments of post-mastectomy patients is influenced by the presence of a tissue expander for various beam orientations. The impact of TTEs on dose distributions establishes the importance of an accurately modelled high-density implant in the treatment planning system for post-mastectomy patients.
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Affiliation(s)
- A Asena
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia.
| | - T Kairn
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia; Genesis CancerCare Queensland, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, QLD 4066, Australia
| | - S B Crowe
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia
| | - J V Trapp
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia
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Smith ST, Kairn T, Crowe SB, Asena A, Trapp JV. Characterisation of the half-field beam penumbra for a variety of blocking set-ups. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1742-6596/573/1/012073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kairn T, Ibrahim S, Inness E, Crowe SB, Trapp JV. Suitability of Diodes for Point Dose Measurements in IMRT/VMAT Beams. IFMBE Proceedings 2015. [DOI: 10.1007/978-3-319-19387-8_160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Charles PH, Cranmer-Sargison G, Thwaites DI, Kairn T, Crowe SB, Pedrazzini G, Aland T, Kenny J, Langton CM, Trapp JV. Design and experimental testing of air slab caps which convert commercial electron diodes into dual purpose, correction-free diodes for small field dosimetry. Med Phys 2014; 41:101701. [DOI: 10.1118/1.4894728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Crowe SB, Kairn T, Kenny J, Knight RT, Hill B, Langton CM, Trapp JV. Treatment plan complexity metrics for predicting IMRT pre-treatment quality assurance results. Australas Phys Eng Sci Med 2014; 37:475-82. [DOI: 10.1007/s13246-014-0274-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 04/22/2014] [Indexed: 10/25/2022]
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Kairn T, Crowe SB, Charles PH, Trapp JV. Using narrow beam profiles to quantify focal spot size, for accurate Monte Carlo simulations of SRS/SRT systems. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/489/1/012014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Charles PH, Crowe SB, Kairn T, Knight R, Hill B, Kenny J, Langton CM, Trapp JV. The influence of Monte Carlo source parameters on detector design and dose perturbation in small field dosimetry. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/489/1/012006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Charles PH, Cranmer-Sargison G, Thwaites DI, Crowe SB, Kairn T, Knight RT, Kenny J, Langton CM, Trapp JV. A practical and theoretical definition of very small field size for radiotherapy output factor measurements. Med Phys 2014; 41:041707. [DOI: 10.1118/1.4868461] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kairn T, Crowe SB, Trapp JV. Correcting radiation survey data to account for increased leakage during intensity modulated radiotherapy treatments. Med Phys 2013; 40:111708. [DOI: 10.1118/1.4823776] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Charles PH, Crowe SB, Kairn T, Knight RT, Hill B, Kenny J, Langton CM, Trapp JV. Monte Carlo-based diode design for correction-less small field dosimetry. Phys Med Biol 2013; 58:4501-12. [DOI: 10.1088/0031-9155/58/13/4501] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kakakhel M, Kairn T, Kenny J, Seet K, Fielding A, Trapp J. Interplay effects during enhanced dynamic wedge deliveries. Phys Med 2013; 29:323-32. [DOI: 10.1016/j.ejmp.2012.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/01/2012] [Accepted: 04/24/2012] [Indexed: 12/25/2022] Open
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Crowe SB, Kairn T, Trapp JV, Fielding AL. Monte Carlo evaluation of collapsed-cone convolution calculations in head and neck radiotherapy treatment plans. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/978-3-642-29305-4_474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Charles PH, Crowe SB, Kairn T, Kenny J, Lehmann J, Lye J, Dunn L, Hill B, Knight RT, Langton CM, Trapp JV. The effect of very small air gaps on small field dosimetry. Phys Med Biol 2012; 57:6947-60. [DOI: 10.1088/0031-9155/57/21/6947] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kairn T, Warne D, Kenny J, Fielding A, Trapp J, Dwyer M. Corrigendum to “Accurately simulating the production of radiotherapy portal images using non-zero beam angles” [Radiat. Meas. 46 (2011) 1967–1970]. RADIAT MEAS 2012. [DOI: 10.1016/j.radmeas.2012.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kairn T, Taylor ML, Crowe SB, Dunn L, Franich RD, Kenny J, Knight RT, Trapp JV. Monte Carlo verification of gel dosimetry measurements for stereotactic radiotherapy. Phys Med Biol 2012; 57:3359-69. [DOI: 10.1088/0031-9155/57/11/3359] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Kairn T, Aland T, Hardcastle N, Hill B, Kenny J, Knight R, Meldrum R, Middlebrook N, Tome W. SU-E-T-143: Quality Assurance of Complex Rotational and Stereotactic IMRT Treatments Using Gafchromic EBT2 Film. Med Phys 2011. [DOI: 10.1118/1.3612094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Taylor M, Kairn T, Kron T, Dunn L, Franich R. 1136 poster THE INFLUENCE OF SPECTRAL CHANGES IN NON-REFERENCE CONDITIONS ON STOPPING POWER RATIOS IN SMALL-FIELD DOSIMETRY. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)71258-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kakakhel MB, Baveas ES, Fielding AL, Kairn T, Kenny J, Trapp JV. Validation and automation of the DYNJAWS component module of the BEAMnrc Monte Carlo code. Australas Phys Eng Sci Med 2011; 34:83-90. [PMID: 21424376 DOI: 10.1007/s13246-011-0060-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 02/21/2011] [Indexed: 12/17/2022]
Abstract
The purpose of this work is to validate and automate the use of DYNJAWS; a new component module (CM) in the BEAMnrc Monte Carlo (MC) user code. The DYNJAWS CM simulates dynamic wedges and can be used in three modes; dynamic, step-and-shoot and static. The step-and-shoot and dynamic modes require an additional input file defining the positions of the jaw that constitutes the dynamic wedge, at regular intervals during its motion. A method for automating the generation of the input file is presented which will allow for the more efficient use of the DYNJAWS CM. Wedged profiles have been measured and simulated for 6 and 10 MV photons at three field sizes (5 cm × 5 cm, 10 cm × 10 cm and 20 cm × 20 cm), four wedge angles (15°, 30°, 45° and 60°), at d (max) and at 10 cm depth. Results of this study show agreement between the measured and the MC profiles to within 3% of absolute dose or 3 mm distance to agreement for all wedge angles at both energies and depths. The gamma analysis suggests that dynamic mode is more accurate than the step-and-shoot mode. The DYNJAWS CM is an important addition to the BEAMnrc code and will enable the MC verification of patient treatments involving dynamic wedges.
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Affiliation(s)
- M B Kakakhel
- Physics, Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, QLD, 4001, Australia
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Kairn T, Khoei S, Markwell TS, Fielding AL, Trapp JV. Contrast enhancement of EPID images via difference imaging: a feasibility study. Phys Med Biol 2010; 55:N533-45. [DOI: 10.1088/0031-9155/55/22/n02] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kairn T, Aland T, Franich RD, Johnston PN, Kakakhel MB, Kenny J, Knight RT, Langton CM, Schlect D, Taylor ML, Trapp JV. Adapting a generic BEAMnrc model of the BrainLAB m3 micro-multileaf collimator to simulate a local collimation device. Phys Med Biol 2010; 55:N451-63. [DOI: 10.1088/0031-9155/55/17/n01] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
To enhance the utility of radiochromic films for high-resolution dosimetry of small and modulated radiotherapy fields, we propose a means to negate the effects of heterogeneities in EBT2 (and other) films. The results of using our simple procedure for evaluating radiation dose in EBT2 film are compared with the results of using the manufacturer's recommended procedure as well as a procedure previously established for evaluating dose in older EBT film. It is shown that Newton's ring-like scanning artefacts can be avoided through the use of a plastic frame, to elevate the film above the scanner's surface. The effects of film heterogeneity can be minimized by evaluating net optical density, pixelwise, as the logarithm of the ratio of the red-channel pixel value in each pixel of each irradiated film to the red-channel pixel value in the same pixel in the same film prior to irradiation. The application of a blue-channel correction was found to result in increased noise. It is recommended that, when using EBT2 film for radiotherapy quality assurance, the films should be scanned before and after irradiation and analysed using the method proposed herein, without the use of the blue-channel correction, in order to produce dose images with minimal film heterogeneity effects.
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Kairn T, Kenny J, Crowe SB, Fielding AL, Franich RD, Johnston PN, Knight RT, Langton CM, Schlect D, Trapp JV. Technical Note: Modeling a complex micro-multileaf collimator using the standard BEAMnrc distribution. Med Phys 2010; 37:1761-7. [DOI: 10.1118/1.3355873] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kairn T, Crowe SB, Poole CM, Fielding AL. Effects of collimator backscatter in an Elekta linac by Monte Carlo simulation. ACTA ACUST UNITED AC 2009; 32:129-35. [DOI: 10.1007/bf03178640] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kairn T, Cassidy D, Sandford PM, Fielding AL. Radiotherapy treatment verification using radiological thickness measured with an amorphous silicon electronic portal imaging device: Monte Carlo simulation and experiment. Phys Med Biol 2008; 53:3903-19. [DOI: 10.1088/0031-9155/53/14/012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kairn T, Daivis PJ, Ivanov I, Bhattacharya SN. Molecular-dynamics simulation of model polymer nanocomposite rheology and comparison with experiment. J Chem Phys 2007; 123:194905. [PMID: 16321111 DOI: 10.1063/1.2110047] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The shear-rate dependence of viscosity is studied for model polymer melts containing various concentrations of spherical filler particles by molecular-dynamics simulations, and the results are compared with the experimental results for calcium-carbonate-filled polypropylene. Although there are some significant differences in scale between the simulated model polymer composite and the system used in the experiments, some important qualitative similarities in shear behavior are observed. The trends in the steady-state shear viscosities of the simulated polymer-filler system agree with those seen in the experimental results; shear viscosities, zero-shear viscosities, and the rate of shear thinning are all seen to increase with filler content in both the experimental and simulated systems. We observe a significant difference between the filler volume fraction dependence of the zero-shear viscosity of the simulated system and that of the experimental system that can be attributed to a large difference in the ratio of the filler particle radius to the radius of gyration of the polymer molecules. In the simulated system, the filler particles are so small that they only have a weak effect on the viscosity of the composite at low filler volume fraction, but in the experimental system, the viscosity of the composite increases rapidly with increasing filler volume fraction. Our results indicate that there exists a value of the ratio of the filler particle radius to the polymer radius of gyration such that the zero-shear-rate viscosity of the composite becomes approximately independent of the filler particle volume fraction.
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Affiliation(s)
- T Kairn
- Department of Applied Physics, School of Applied Sciences, Royal Melbourne Institute of Technology (RMIT) University, G.P.O. Box 2476V, Melbourne, Victoria 3001, Australia
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