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Martin A, Carignan D, Beaudry M, Menard E, Foster W, Vigneault E, Magnan S, Lachance B, Poulin E, Archambault L, Lacroix F, Beaulieu L, Després P. Ultra-Hypo Fractionated Prostate IGRT with HDR Brachytherapy Boost as Compared to a Moderate-Hypo Fractionated Approach: Patient Reported Outcomes (PRO's) of a Phase Two Study Interim Analysis. Int J Radiat Oncol Biol Phys 2022. [DOI: 10.1016/j.ijrobp.2022.07.1189] [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: 11/30/2022]
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2
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Cloutier E, Beaulieu L, Archambault L. On the use of polychromatic cameras for high spatial resolution spectral dose measurements. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6b0e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/27/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. Despite the demonstrated benefits of hyperspectral formalism for stem effect corrections in the context of fiber dose measurements, this approach has not been yet translated into volumetric measurements where cameras are typically used for their distinguishing spatial resolution. This work investigates demosaicing algorithms for polychromatic cameras based spectral imaging. Approach. The scintillation and Cherenkov signals produced in a radioluminescent phantom are imaged by a polychromatic camera and isolated using the spectral formalism. To do so, five demosaicing algorithms are investigated from calibration to measurements: a clustering method and four interpolation algorithms. The resulting accuracy of scintillation and Cherenkov images is evaluated with measurements of the differences (mean ± standard deviation) between the obtained and expected signals from profiles drawn across a scintillation spot. Signal-to-noise ratio and signal-to-background ratio are further measured and compared in the resulting scintillation images. Finally, the resulting differences on the scintillation signal from a 0.2 × 0.2 cm2 region-of-interest (ROI) were reported. Main results. Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively yielded differences of 3 ± 5%, 1 ± 3%, 1 ± 3%, 1 ± 2% and 2 ± 4% in the resulting scintillation images. For the Cherenkov images, all algorithms provided differences below 1%. All methods enabled measurements over the detectability (SBR > 2) and sensitivity (SNR > 5) thresholds with the bilinear algorithm providing the best SNR value. Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively provided differences on the ROI analysis of 7 ± 5%, 3 ± 2%, 3 ± 2%, 4 ± 2%, 7 ± 3%. Significance. Radioluminescent signals can accurately be isolated using a single polychromatic camera. Moreover, demosaicing using a bilinear kernel provided the best results and enabled Cherenkov signal subtraction while preserving the full spatial resolution of the camera.
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Martin A, Carignan D, Beaudry M, Ménard É, Foster W, Vigneault É, Magnan S, Lachance B, Poulin É, Lacroix F, Archambault L, Beaulieu L, Després P. PD-0579 Ultra-hypo compared to moderate-hypo fractionated prostate IGRT with HDR brachytherapy boost. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02894-8] [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: 11/29/2022]
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Cloutier E, Beaulieu L, Archambault L. OC-0122 Accurate in water electron beam dose measurements using polarization imaging. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02498-7] [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: 11/16/2022]
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Perron-Gagnon L, Archambault L, Varfalvy N, Piron O, Theberge V. Breast Deformations Measured With Cone Beam Computed Tomography During Adjuvant Radiotherapy for Breast Cancer. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.1458] [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: 11/26/2022]
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Bertolini M, Vazquez Munoz R, Archambault L, Shah S, Souza JGS, Costa RC, Thompson A, Zhou Y, Sobue T, Dongari-Bagtzoglou A. Mucosal Bacteria Modulate Candida albicans Virulence in Oropharyngeal Candidiasis. mBio 2021; 12:e0193721. [PMID: 34399623 PMCID: PMC8406182 DOI: 10.1128/mbio.01937-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 07/09/2021] [Indexed: 01/12/2023] Open
Abstract
Oropharyngeal candidiasis (OPC) is the most prevalent oral infection in immunocompromised patients, primarily associated with Candida albicans. Increasing evidence points to a significant role of mucosal bacteria on the transition of C. albicans from commensal to pathogenic. In this work, we hypothesized that changes in the abundance or composition of the mucosal bacterial microbiota induced by dietary sucrose during the development of OPC can modulate C. albicans virulence. C. albicans burdens and mucosal lesions were evaluated in a mouse cortisone immunosuppression model amended with sucrose. We also analyzed the mucosal bacterial composition using 16S rRNA gene sequencing and culture methods. In immunocompetent mice, sucrose significantly increased total bacterial burdens and reduced alpha diversity, by increasing the relative abundance of mitis group streptococci. In immunocompromised mice, C. albicans infection was associated with a significantly reduced bacterial alpha diversity due to an increase in the relative abundance of enterococci. When exposed to dietary sucrose, these mice had reduced C. albicans burdens and reduced bacterial alpha diversity, associated with an increase in the relative abundance of Lactobacillus. SparCC correlation networks showed a significant negative correlation between Lactobacillus and Enterococcus in all Candida-infected mice. Depletion of lactobacilli with antibiotic treatment partially restored C. albicans burdens in mice receiving sucrose. In coculture in vitro experiments, mouse oral Lactobacillus johnsonii isolates inhibited growth of Enterococcus faecalis isolates and C. albicans. These results support the hypothesis that the sucrose-induced attenuation of C. albicans virulence was a result of changes in the mucosal bacterial microbiome characterized by a reduction in enterococci and an increase in lactobacilli. IMPORTANCE By comparing Candida albicans virulence and the mucosal bacterial composition in a mouse oral infection model, we were able to dissect the effects of the host environment (immunosuppression), infection with C. albicans, and local modulating factors (availability of sucrose as a carbon source) on the mucosal bacterial microbiome and its role on fungal virulence. We showed that changes in endogenous microbial communities in response to sucrose can lead to attenuation of fungal disease. We also showed that Lactobacillus johnsonii may curtail Candida virulence both by inhibiting its growth and by inhibiting the growth of potentially synergistic bacteria such as enterococci. Our results support the concept that Candida pathogenesis should be viewed in the contexts of both a susceptible host and a mucosal bacterial microbiota conducive to virulence.
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Affiliation(s)
- M. Bertolini
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
| | - R. Vazquez Munoz
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
| | - L. Archambault
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
| | - S. Shah
- Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - J. G. S. Souza
- Dental Research Division, Guarulhos University, Guarulhos, SP, Brazil
- Dental Science School (Faculdade de Ciências Odontológicas [FCO]), Montes Claros, MG, Brazil
| | - R. C. Costa
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, SP, Brazil
| | - A. Thompson
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
| | - Y. Zhou
- Department of Medicine, UConn Health, Connecticut, Farmington, Connecticut, USA
| | - T. Sobue
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
| | - A. Dongari-Bagtzoglou
- Department of Oral Health and Diagnostic Sciences, UConn Health, Farmington, Connecticut, USA
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Cloutier E, Beaulieu L, Archambault L. Deformable scintillation dosimeter: II. Real-time simultaneous measurements of dose and tracking of deformation vector fields. Phys Med Biol 2021; 66. [PMID: 34380121 DOI: 10.1088/1361-6560/ac1ca2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 01/21/2021] [Accepted: 08/11/2021] [Indexed: 12/29/2022]
Abstract
Anatomical motion and deformation pose challenges to the understanding of the delivered dose distribution during radiotherapy treatments. Hence, deformable image registration (DIR) algorithms are increasingly used to map contours and dose distributions from one image set to another. However, the lack of validation tools slows their clinical adoption, despite their commercial availability. This work presents a novel water-equivalent deformable dosimeter that simultaneously measures the dose distribution and tracks deformation vector fields (DVF). The dosimeter in made of an array of 19 scintillating fiber detectors embedded in a cylindrical elastomer matrix. It is imaged by two pairs of stereoscopic cameras tracking the position and angulation of the scintillators, while measuring the dose. The resulting system provides a precision of 0.3 mm on DVF measurements. The dosimeter was irradiated with 5 × 3, 4 × 3 and 3 × 3 cm26 MV photon beams in both fixed and deformed conditions. The measured DVF was compared to the one computed with a DIR algorithm (Plastimatch). The deviations between the computed and measured DVFs was below 1.5 mm. As for dose measurements, the dosimeter acquired the dose distribution in fixed and deformed conditions within 1% of the treatment planning system calculation and complementary dose validation using the Hyperscint dosimetry system. Using the demonstrated qualities of scintillating detectors, we developed a real-time, water-equivalent deformable dosimeter. Given it's sensor tracking position precision and dose measurements accuracy, the developed detector is a promising tools for the validation of DIR algorithms as well as dose distribution measurements under fixed and deformed conditions.
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Affiliation(s)
- E Cloutier
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
| | - L Beaulieu
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
| | - L Archambault
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
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Cloutier E, Archambault L, Beaulieu L. Deformable scintillation dosimeter I: challenges and implementation using computer vision techniques. Phys Med Biol 2021; 66. [PMID: 34380116 DOI: 10.1088/1361-6560/ac1ca1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 01/21/2021] [Accepted: 08/11/2021] [Indexed: 01/18/2023]
Abstract
Plastic scintillation detectors are increasingly used to measure dose distributions in the context of radiotherapy treatments. Their water-equivalence, real-time response and high spatial resolution distinguish them from traditional detectors, especially in complex irradiation geometries. Their range of applications could be further extended by embedding scintillators in a deformable matrix mimicking anatomical changes. In this work, we characterized signal variations arising from the translation and rotation of scintillating fibers with respect to a camera. Corrections are proposed using stereo vision techniques and two sCMOS complementing a CCD camera. The study was extended to the case of a prototype real-time deformable dosimeter comprising an array of 19 scintillating fibers. The signal to angle relationship follows a gaussian distribution (FWHM = 52°) whereas the intensity variation from radial displacement follows the inverse square law. Tracking the position and angle of the fibers enabled the correction of these spatial dependencies. The detecting system provides an accuracy and precision of respectively 0.08 mm and 0.3 mm on the position detection. This resulted in an uncertainty of 2° on the angle measurement. Displacing the dosimeter by ±3 cm in depth resulted in relative intensities of 100 ± 10% (mean ± standard deviation) to the reference position. Applying corrections reduced the variations thus resulting in relative intensities of 100 ± 1%. Similarly, for lateral displacements of ±3 cm, intensities went from 98 ± 3% to 100 ± 1% after the correction. Therefore, accurate correction of the signal collected by a camera imaging the output of scintillating elements in a 3D volume is possible. This work paves the way to the development of real-time scintillator-based deformable dosimeters.
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Affiliation(s)
- E Cloutier
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
| | - L Archambault
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
| | - L Beaulieu
- Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada.,Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancer, Université Laval, Québec, Canada
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Wolfs C, Varfalvy N, Canters R, Nijsten S, Archambault L, Verhaegen F. PH-0651: Validating a hidden Markov model for lung anatomical change classification using EPID dosimetry. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00673-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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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Lavoie-Gagnon H, Lacroix F, Poulin E, Martin A, Archambault L, Vigneault E, Foster W, Pilote L. The Advantages of Trus-Based HDR Prostate Treatment When Compared to CT Planning. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.900] [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: 11/30/2022]
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Lavoiegagnon H, Poulin E, Martin A, Pilote L, Vigneault E, Foster W, Archambault L, Lacroix F. OC-0400 Are prostate contours affected by the RO's clinical experience in prostate HDR brachytherapy? Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)30820-5] [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: 11/15/2022]
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Kroshko A, Morin O, Archambault L. PO-0945 Stochastic Frontier Analysis to predict sparing of organs-at-risk for VMAT-treated prostate cancer. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31365-9] [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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Beaulieu L, Gingras L, Bergeron M, Archambault L. SU-F-E-17: A Dedicated Teaching and Research Linac as a Stepping Stone to Introduce Medical Physics to Students. Med Phys 2016. [DOI: 10.1118/1.4955703] [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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Rilling M, Goulet M, Beaulieu L, Thibault S, Archambault L. SU-C-201-04: Noise and Temporal Resolution in a Near Real-Time 3D Dosimeter. Med Phys 2016. [DOI: 10.1118/1.4955544] [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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Archambault L, Papaconstadopoulos P, Seuntjens J, Bouchard H. TH-CD-201-04: A Study of Cherenkov Light Generated and Collected in Plastic Scintillation Detector. Med Phys 2016. [DOI: 10.1118/1.4958126] [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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Archambault L, Piron O, Varfalvy N. SU-D-BRA-05: Time Series Analysis of EPID Images to Identify Patients in Need of Treatment Adaptation. Med Phys 2016. [DOI: 10.1118/1.4955638] [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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Laberge S, Beauregard J, Archambault L. SU-F-R-28: Correction of FCh-PET Bladder Uptake Using Virtual Sinograms and Investigation of Its Impact On the Quantification of Prostate Textural Characteristics. Med Phys 2016. [DOI: 10.1118/1.4955800] [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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Piron O, Varfalvy N, Archambault L. EP-1818: Using ROIs projected on EPID as a predictor of plan deterioration due to anatomical changes. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)33069-9] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rilling M, Goulet M, Thibault S, Archambault L. SU-D-213-03: Towards An Optimized 3D Scintillation Dosimetry Tool for Quality Assurance of Dynamic Radiotherapy Techniques. Med Phys 2015. [DOI: 10.1118/1.4923855] [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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Fillion O, Gingras L, Archambault L. SU-E-J-106: The Use of Deformable Image Registration with Cone-Beam CT for a Better Evaluation of Cumulative Dose to Organs. Med Phys 2015. [DOI: 10.1118/1.4924193] [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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Laliberte-Houdeville C, Beaulieu L, Archambault L. TH-CD-304-09: Simple and Automatic Calibration Technique for Plastic Scintillation Dosimeters. Med Phys 2015. [DOI: 10.1118/1.4926215] [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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Papaconstadopoulos P, Archambault L, Seuntjens J. SU-C-304-03: Experimental Investigation On the Accuracy of Plastic Scintillation Dosimeters in Small Fields. Med Phys 2015. [DOI: 10.1118/1.4923791] [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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Piron O, Varfalvy N, Archambault L. MO-F-CAMPUS-J-05: Using 2D Relative Gamma Analysis From EPID Image as a Predictor of Plan Deterioration Due to Anatomical Changes. Med Phys 2015. [DOI: 10.1118/1.4925466] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Papaconstadopoulos P, Archambault L, Seuntjens J. OC-0149: On the accuracy of the Exradin W1 and the spectrum calibration method in scintillation dosimetry for small fields. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40147-1] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Gagne MC, Tremblay D, Varfalvy N, Archambault L. TU-C-17A-08: Improving IMRT Planning and Reducing Inter-Planner Variability Using the Stochastic Frontier Method: Validation Based On Clinical and Simulated Data. Med Phys 2014. [DOI: 10.1118/1.4889283] [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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Goulet M, Rilling M, Gingras L, Beddar S, Beaulieu L, Archambault L. SU-F-BRE-07: Experimental Validation of a Lung SBRT Technique Using a Novel, True Volumetric Plenoptic-Plastic-Scintillator Detector. Med Phys 2014. [DOI: 10.1118/1.4889045] [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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Fillion O, Gingras L, Archambault L. SU-F-BRF-14: Increasing the Accuracy of Dose Calculation On Cone-Beam Imaging Using Deformable Image Registration in the Case of Prostate Translation. Med Phys 2014. [DOI: 10.1118/1.4889083] [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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Gagne M, Tremblay D, Varfalvy N, Archambault L. OC-0391: Improving IMRT planning using the stochastic frontier method. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30496-5] [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: 11/28/2022]
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Bourgouin A, Varfalvy N, Beaulieu L, Archambault L. Reducing Radiation Doses Received by Cardiac Devices. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.1811] [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: 11/28/2022]
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Archambault L, Poenisch F, Sahoo N, Robertson D, Lee A, Gillin MT, Mohan R, Beddar S. Verification of proton range, position, and intensity in IMPT with a 3D liquid scintillator detector system. Med Phys 2013; 39:1239-46. [PMID: 22380355 DOI: 10.1118/1.3681948] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Intensity-modulated proton therapy (IMPT) using spot scanned proton beams relies on the delivery of a large number of beamlets to shape the dose distribution in a highly conformal manner. The authors have developed a 3D system based on liquid scintillator to measure the spatial location, intensity, and depth of penetration (energy) of the proton beamlets in near real-time. METHODS The detector system consists of a 20 × 20 × 20 cc liquid scintillator (LS) material in a light tight enclosure connected to a CCD camera. This camera has a field of view of 25.7 by 19.3 cm and a pixel size of 0.4 mm. While the LS is irradiated, the camera continuously acquires images of the light distribution produced inside the LS. Irradiations were made with proton pencil beams produced with a spot-scanning nozzle. Pencil beams with nominal ranges in water between 9.5 and 17.6 cm were scanned to irradiate an area of 10 × 10 cm square on the surface of the LS phantom. Image frames were acquired at 50 ms per frame. RESULTS The signal to noise ratio of a typical Bragg peak was about 170. Proton range measured from the light distribution produced in the LS was accurate to within 0.3 mm on average. The largest deviation seen between the nominal and measured range was 0.6 mm. Lateral position of the measured pencil beam was accurate to within 0.4 mm on average. The largest deviation seen between the nominal and measured lateral position was 0.8 mm; however, the accuracy of this measurement could be improved by correcting light scattering artifacts. Intensity of single proton spots were measured with precision ranging from 3 % for the smallest spot intensity (0.005 MU) to 0.5 % for the largest spot (0.04 MU). CONCLUSIONS Our LS detector system has been shown to be capable of fast, submillimeter spatial localization of proton spots delivered in a 3D volume. This system could be used for beam range, intensity and position verification in IMPT.
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Affiliation(s)
- L Archambault
- Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
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Archambault L, Gingras L. SU-D-WAB-04: Restoration of CBCT Images by Deformable Registration for Plan Evaluation and Replanning. Med Phys 2013. [DOI: 10.1118/1.4814028] [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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Goulet M, Gingras L, Beddar S, Beaulieu L, Archambault L. TU-C-108-02: Novel Full 3D Water-Equivalent Dosimetry Technique Using a Single Light-Field Camera for Photons, Electrons and Ion-Beams Dosimetry. Med Phys 2013. [DOI: 10.1118/1.4815366] [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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Cantin A, Octave N, Goudreault J, Foster W, Lachance B, Beaulieu L, Archambault L, Gingras L. SU-E-T-593: Comparison of Three IMRT Adaptive Methods: The Case of Prostate Cancer. Med Phys 2013. [DOI: 10.1118/1.4815021] [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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Vincent SD, Archambault L. SU-E-J-70: Intra and Intermodality Validation of Registration Algorithms On a Deformable Phantom. Med Phys 2013. [DOI: 10.1118/1.4814282] [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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37
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Archambault L, Beaulieu L, Klein D, Bourgouin A, Wootton L, Therriault-Proulx F, Beddar S. OC-0067: Performance of the first commercial miniature plastic scintillation detector. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)32373-2] [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: 11/30/2022]
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Wang LLW, Perles LA, Archambault L, Sahoo N, Mirkovic D, Beddar S. Determination of the quenching correction factors for plastic scintillation detectors in therapeutic high-energy proton beams. Phys Med Biol 2012; 57:7767-81. [PMID: 23128412 DOI: 10.1088/0031-9155/57/23/7767] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Plastic scintillation detectors (PSDs) have many advantages over other detectors in small field dosimetry due to their high spatial resolution, excellent water equivalence and instantaneous readout. However, in proton beams, the PSDs undergo a quenching effect which makes the signal level reduced significantly when the detector is close to the Bragg peak where the linear energy transfer (LET) for protons is very high. This study measures the quenching correction factor (QCF) for a PSD in clinical passive-scattering proton beams and investigates the feasibility of using PSDs in depth-dose measurements in proton beams. A polystyrene-based PSD (BCF-12, ϕ0.5 mm × 4 mm) was used to measure the depth-dose curves in a water phantom for monoenergetic unmodulated proton beams of nominal energies 100, 180 and 250 MeV. A Markus plane-parallel ion chamber was also used to get the dose distributions for the same proton beams. From these results, the QCF as a function of depth was derived for these proton beams. Next, the LET depth distributions for these proton beams were calculated by using the MCNPX Monte Carlo code, based on the experimentally validated nozzle models for these passive-scattering proton beams. Then the relationship between the QCF and the proton LET could be derived as an empirical formula. Finally, the obtained empirical formula was applied to the PSD measurements to get the corrected depth-dose curves and they were compared to the ion chamber measurements. A linear relationship between the QCF and LET, i.e. Birks' formula, was obtained for the proton beams studied. The result is in agreement with the literature. The PSD measurements after the quenching corrections agree with ion chamber measurements within 5%. PSDs are good dosimeters for proton beam measurement if the quenching effect is corrected appropriately.
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Affiliation(s)
- L L W Wang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Therriault-Proulx F, Beddar S, Archambault L, Beaulieu L. Sci-Thur PM: YIS - 10: A new optically encoded single-fiber plastic scintillation detector for multi-point radiation dosimetry. Med Phys 2012; 39:4623-4624. [PMID: 28516538 DOI: 10.1118/1.4740107] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To develop a new multi-point plastic scintillation detector (mPSD) that allows for simultaneous dose measurements at multiple points and uses a single optical guide. MATERIALS AND METHODS Two different prototypes were built. A two-point mPSD was built and light discrimination was based on the use of multiple color filters at the outputs of a network of optical fiber splitters. Light intensity was measured by an EMCCD camera. For the three-point mPSD, the light discrimination setup was replaced by a low-noise spectrometer. Depth-dose and profiles measurements were obtained on a 6 MV photon beam with the mPSDs inside a water phantom. An ion chamber was also used for comparison purpose. Finally, the three-point mPSD was tested under an Ir-192 high-dose-rate (HDR) brachytherapy dose delivery and compared to the treatment planning system. RESULTS A good agreement was found between the measured and expected dose for both mPSDs. The average relative differences to the ion chamber measurement for the two-point mPSD were of (2.4 ± 1.6)% and (1.3 ± 0.8)%. For the three-point mPSD, these differences were of (2.3±1.1)%, (1.6±0.4)% and (0.32±0.19)%. The latter mPSD was shown very versatile, being able to measure dose from HDR brachytherapy with an average accuracy of (2.3±1.0)% per catheter. CONCLUSIONS The practical feasibility of mPSDs using a single optical guide has been demonstrated under irradiation from a 6 MV photon beam and an Ir-192 HDR brachytherapy source. Their application for pre-treatment quality assurance and in vivo dosimetry will be various.
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Affiliation(s)
- F Therriault-Proulx
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,Département de Physique, de Génie Physique et d'Optique, Université Laval, Québec, QC, Canada
| | - S Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - L Archambault
- Département de Physique, de Génie Physique et d'Optique, Université Laval, Québec, QC, Canada.,Département de Radio-Oncologie, Hôtel-Dieu de Québec, CHUQ, Québec, QC, Canada
| | - L Beaulieu
- Département de Physique, de Génie Physique et d'Optique, Université Laval, Québec, QC, Canada.,Département de Radio-Oncologie, Hôtel-Dieu de Québec, CHUQ, Québec, QC, Canada
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Gauthier JF, Varfalvy N, Cyr MF, Archambault L. Poster - Thur Eve - 35: Characterization of performance of two deformable registration software. Med Phys 2012; 39:4631. [DOI: 10.1118/1.4740143] [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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Goulet M, Archambault L, Beaulieu L, Gingras L. Sci-Thur PM: YIS - 05: Tomographic dosimetry using scintillating fibers and its application to 2D and 3D dosimetry. Med Phys 2012; 39:4622-4623. [DOI: 10.1118/1.4740102] [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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Vincent SD, Archambault L. SU-E-J-85: Anthropomorphic Development for Intermodality Deformation Algorithms Validation. Med Phys 2012; 39:3672. [PMID: 28519777 DOI: 10.1118/1.4734920] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radiation therapy is often based on a single treatment plan calculated on patient's anatomy at the time of the simulation scan. Deformation algorithms offer the possibility to register initial treatment plan on a daily CBCT. This way, the planning can be adapted to the evolution of patient anatomy. Validation of deformable image registration algorithms (DRA) ideally requires the use of phantoms offering some deformation possibilitiesMethods: An anthropomorphic, pelvic phantom was built to test volume variation (bladder), deformation of contours (prostate) and translation (all organs). Algorithms must be able to perform intermodality registration. Therefore, images were acquired for both CT and CBCT. The phantom has been created in a way to allow total control of the deformation amplitude. Each of the three types of deformations studied were realized independently and scanned in a manner to have the same initial and deformed images set for each modality. RESULTS Two algorithm systems were use to compare their efficiency; an open-source software, a toolbox for registration that offers parameter adjustment and a commercial system with limited control for user. The phantom provides us usable images for DRA validation. For a 2 cm mass center organ translation, the first one reduced 98% of the distance while the other only performed 60%. For a 100 ml volume variation, we get 88% and 62%. CONCLUSIONS Comparison of each intermodal deformation registration performed by the two algorithm systems show how control on parameters improves registration quality. DRA allow the initial planning adaptation on different deformations which occur in human body.
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Affiliation(s)
- S D Vincent
- CHUQ Pavillon Hotel-Dieu de Quebec, Quebec, QC
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Bourgouin A, Varfalvy N, Beaulieu L, Archambault L. SU-E-T-265: Reducing Pacemaker Doses with a Lead Sheet: A Multi-Detector Study. Med Phys 2012; 39:3764. [DOI: 10.1118/1.4735332] [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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Therriault-Proulx F, Beaulieu L, Archambault L, Beddar S. WE-G-BRB-04: BEST IN PHYSICS (THERAPY) - A Novel Multi-Point Plastic Scintillation Detector for in Vivo Dosimetry and Quality Assurance in Radiation Therapy. Med Phys 2012; 39:3967. [DOI: 10.1118/1.4736190] [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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Goulet M, Archambault L, Beaulieu L, Gingras L. TU-A-BRB-01: Groundbreaking 2D and 3D Dosimetry Techniques Using Scintillating Fibers and Tomographic Reconstruction. Med Phys 2012. [DOI: 10.1118/1.4735858] [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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Goulet M, Gingras L, Depauw N, Archambault L, Seco J, Beaulieu L. WE-G-BRB-06: Real-Time Radiation Field Tracking Using Long Scintillating Fibers. Med Phys 2012; 39:3968. [DOI: 10.1118/1.4736192] [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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Therriault-Proulx F, Beaulieu L, Archambault L, Beddar S. WE-G-BRB-05: On the Importance of Fluorescence Within the Stem Effect of Scintillation Detectors. Med Phys 2012; 39:3967-3968. [DOI: 10.1118/1.4736191] [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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Archambault L, Theriault Proulx F, Beddar S, Beaulieu L. PO-0807 FORMALISM FOR HYPER-SPECTRAL, MULTI-POINT, PLASTIC SCINTILLATION DETECTORS. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71140-4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Goulet M, Archambault L, Beaulieu L, Gingras L. OC-0224 HIGH RESOLUTION 2D DOSIMETRY USING LONG SCINTILLATING FIBERS AND TOMOGRAPHIC RECONSTRUCTION. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)70563-7] [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: 10/28/2022]
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Bourgouin A, Bonde C, Adams E, Schmidt D, Beddar S, Beaulieu L, Archambault L. PO-0810 CHARACTERIZATION AND VALIDATION OF A COMMERCIAL PLASTIC SCINTILLATION DETECTOR PROTOTYPE. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71143-x] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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