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Karger CP, Elter A, Dorsch S, Mann P, Pappas E, Oldham M. Validation of complex radiotherapy techniques using polymer gel dosimetry. Phys Med Biol 2024; 69:06TR01. [PMID: 38330494 DOI: 10.1088/1361-6560/ad278f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
Modern radiotherapy delivers highly conformal dose distributions to irregularly shaped target volumes while sparing the surrounding normal tissue. Due to the complex planning and delivery techniques, dose verification and validation of the whole treatment workflow by end-to-end tests became much more important and polymer gel dosimeters are one of the few possibilities to capture the delivered dose distribution in 3D. The basic principles and formulations of gel dosimetry and its evaluation methods are described and the available studies validating device-specific geometrical parameters as well as the dose delivery by advanced radiotherapy techniques, such as 3D-CRT/IMRT and stereotactic radiosurgery treatments, the treatment of moving targets, online-adaptive magnetic resonance-guided radiotherapy as well as proton and ion beam treatments, are reviewed. The present status and limitations as well as future challenges of polymer gel dosimetry for the validation of complex radiotherapy techniques are discussed.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
| | - Stefan Dorsch
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Evangelos Pappas
- Radiology & Radiotherapy Sector, Department of Biomedical Sciences, University of West Attica, Athens, Greece
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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Valdetaro LB, Jensen MB, Muren LP, Skyt PS, Petersen JBB, Balling P. Technical note: Temporal and thermal stability of optical response for silicone-based 3D radiochromic dosimeters. Med Phys 2022; 50:2560-2564. [PMID: 36585852 DOI: 10.1002/mp.16193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 11/28/2022] [Accepted: 12/13/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Radiochromic silicone-based dosimeters are flexible 3D dosimeters, which at appropriate concentration of leucomalachite green (LMG) and curing agent are dose-rate independent for clinical photon beams. However, their dose response is based on chemical processes that can be influenced by temporal and thermal conditions, impacting measurement stability. PURPOSE The aim of this study was to investigate the temporal stability of the dose response of radiochromic dosimeters for different curing times and post-irradiation storage temperatures. METHODS Six cylindrical dosimeters (5 cm diameter, 5 cm length) were produced in a single batch and separated into two groups that were irradiated 72 and 118 h after production. The same photon plan, consisting of two 10 × 1.6 cm2 opposing fields, was delivered to all dosimeters. After irradiation, the dosimeters were separated into three groups, stored at 5°C, 15°C, and 20°C, and read out for five consecutive days. RESULTS Storage temperature influenced the measurement stability, and changes in the optical response with time differed between irradiated and non-irradiated parts of the dosimeters. The relative change between signal and background was greater than 10% for all measurements performed 24 h or more after irradiation, except for dosimeters stored at 5°C, which changed by 2%-5% after 24 h. The dosimeter temporal stability was not influenced by curing time. CONCLUSIONS For room temperature storage (15°C and 20°C), readout should take place as soon as possible after irradiation since the background color increased rapidly for both curing times (72 and 118 h), whereas the dosimeters are stored at 5°C, readout can be performed up to 24 h after.
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Affiliation(s)
- Lia Barbosa Valdetaro
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Morten Bjørn Jensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | - Ludvig Paul Muren
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Jørgen Breede Baltzer Petersen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Balling
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
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Moradi S, Hashemi B, Bakhshandeh M, Banaei A, Mofid B. Introducing new plan evaluation indices for prostate dose painting IMRT plans based on apparent diffusion coefficient images. Radiat Oncol 2022; 17:193. [PMID: 36419067 PMCID: PMC9685857 DOI: 10.1186/s13014-022-02163-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Dose painting planning would be more complicated due to different levels of prescribed doses and more complex evaluation with conventional plan quality indices considering uniform dose prescription. Therefore, we tried to introduce new indices for evaluating the dose distribution conformity and homogeneity of treatment volumes based on the tumoral cell density and relative volumes of each lesion in prostate IMRT. METHODS CT and MRI scans of 20 male patients having local prostate cancer were used for IMRT DP planning. Apparent diffusion coefficient (ADC) images were imported to a MATLAB program to identify lesion regions based on ADC values automatically. Regions with ADC values lower than 750 mm2/s and regions with ADC values higher than 750 and less than 1500 mm2/s were considered CTV70Gy (clinical tumor volume with 70 Gy prescribed dose), and CTV60Gy, respectively. Other regions of the prostate were considered as CTV53Gy. New plan evaluation indices based on evaluating the homogeneity (IOE(H)), and conformity (IOE(C)) were introduced, considering the relative volume of each lesion and cellular density obtained from ADC images. These indices were compared with conventional homogeneity and conformity indices and IOEs without considering cellular density. Furthermore, tumor control probability (TCP) was calculated for each patient, and the relationship of the assessed indices were evaluated with TCP values. RESULTS IOE (H) and IOE (C) with considering cellular density had significantly lower values compared to conventional indices and IOEs without considering cellular density. (P < 0.05). TCP values had a stronger relationship with IOE(H) considering cell density (R2 = -0.415), and IOE(C) without considering cell density (R2 = 0.624). CONCLUSION IOE plan evaluation indices proposed in this study can be used for evaluating prostate IMRT dose painting plans. We suggested to consider cell densities in the IOE(H) calculation formula and it's appropriate to calculate IOE(C) without considering cell density values.
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Affiliation(s)
- Saman Moradi
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Bijan Hashemi
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Mohsen Bakhshandeh
- grid.411600.2Department of Radiology Technology, Faculty of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, 1985717443 Iran
| | - Amin Banaei
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Bahram Mofid
- grid.411600.2Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, 1985717443 Iran
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4
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Valdetaro LB, Høye EM, Skyt PS, Petersen JBB, Balling P, Muren LP. Empirical quenching correction in radiochromic silicone-based three-dimensional dosimetry of spot-scanning proton therapy. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2021; 18:11-18. [PMID: 34258402 PMCID: PMC8254200 DOI: 10.1016/j.phro.2021.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 11/24/2022]
Abstract
Background and purpose Three-dimensional dosimetry of proton therapy (PT) with chemical dosimeters is challenged by signal quenching, which is a lower dose-response in regions with high ionization density due to high linear-energy-transfer (LET) and dose-rate. This study aimed to assess the viability of an empirical correction model for 3D radiochromic silicone-based dosimeters irradiated with spot-scanning PT, by parametrizing its LET and dose-rate dependency. Materials and methods Ten cylindrical radiochromic dosimeters (Ø50 and Ø75 mm) were produced in-house, and irradiated with different spot-scanning proton beam configurations and machine-set dose rates ranging from 56 to 145 Gy/min. Beams with incident energies of 75, 95 and 120 MeV, a spread-out Bragg peak and a plan optimized to an irregular target volume were included. Five of the dosimeters, irradiated with 120 MeV beams, were used to estimate the quenching correction factors. Monte Carlo simulations were used to obtain dose and dose-averaged-LET (LETd) maps. Additionally, a local dose-rate map was estimated, using the simulated dose maps and the machine-set dose-rate information retrieved from the irradiation log-files. Finally, the correction factor was estimated as a function of LETd and local dose-rate and tested on the different fields. Results Gamma-pass-rates of the corrected measurements were >94% using a 3%-3 mm gamma analysis and >88% using 2%-2 mm, with a dose deviation of <5.6 ± 1.8%. Larger dosimeters showed a 20% systematic increase in dose-response, but the same quenching in signal when compared to the smaller dosimeters. Conclusion The quenching correction model was valid for different dosimeter sizes to obtain relative dosimetric maps of complex dose distributions in PT.
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Affiliation(s)
- Lia Barbosa Valdetaro
- Danish Centre for Particle Therapy, Aarhus University Hospital, 8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
| | - Ellen Marie Høye
- Department of Oncology and Medical Physics, Haukeland University Hospital, 5021 Bergen, Norway
| | - Peter Sandegaard Skyt
- Danish Centre for Particle Therapy, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | | | - Peter Balling
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Ludvig Paul Muren
- Danish Centre for Particle Therapy, Aarhus University Hospital, 8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.,Medical Physics, Department of Oncology, Aarhus University Hospital, 8200 Aarhus N, Denmark
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5
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Al Kafi MA, Al Moussa A, Yousof MFM, Maryański MJ, Moftah B. Performance of a new commercial high-definition 3D patient specific quality assurance system for CyberKnife robotic radiotherapy and radiosurgery. RADIAT MEAS 2021. [DOI: 10.1016/j.radmeas.2021.106568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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De Roover R, Hansen R, Crijns W, Muurholm CG, Poels K, Skouboe S, Haustermans K, Poulsen PR, Depuydt T. Dosimetric impact of intrafraction prostate rotation and accuracy of gating, multi-leaf collimator tracking and couch tracking to manage rotation: An end-to-end validation using volumetric film measurements. Radiother Oncol 2020; 156:10-18. [PMID: 33264640 DOI: 10.1016/j.radonc.2020.11.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/30/2020] [Accepted: 11/24/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE Both gating and tracking can mitigate the deteriorating dosimetric impact of intrafraction translation during prostate stereotactic body radiotherapy (SBRT). However, their ability to manage intrafraction rotation has not yet been thoroughly investigated. The dosimetric accuracy of gating, MLC tracking and couch tracking to manage intrafraction prostate rotation was investigated. MATERIALS AND METHODS Treatment plans for end-to-end tests of prostate SBRT with focal boosting were generated for a dynamic anthropomorphic pelvis phantom. The phantom applied internal lateral rotation (up to 25°) and coupled vertical and longitudinal translation of a radiochromic film stack that was used for dose measurements. Dose was delivered for each plan while the phantom applied motion according to three typical prostate motion traces without compensation (i), with gating (ii), with MLC tracking (iii) or with couch tracking (iv). Measured doses for the four motion compensation strategies were compared with the planned dose in terms of γ-index analysis, target coverage and organs at risk (OAR) sparing. RESULTS Intrafraction rotation reduced the 3%(global)/2mm γ-index passing rate (γPR) for the prostate target volume by median (range) -33.2% (-68.6%, -4.1%) when no motion compensation was applied. The use of motion compensation improved the γPR by 13.2% (-0.4%, 32.9%) for gating, by 6.0% (-0.8%, 27.7%) for MLC tracking and by 11.1% (1.2%, 22.9%) for couch tracking. The three compensation techniques improved the target coverage in most cases. Gating showed better OAR sparing than MLC tracking or couch tracking. CONCLUSIONS Compensation of intrafraction prostate rotation with gating, MLC tracking and couch tracking was investigated experimentally for the first time. All three techniques improved the dosimetric accuracy, but residual motion-related dose errors remained due to the lack of rotation correction.
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Affiliation(s)
- Robin De Roover
- Department of Oncology, KU Leuven, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium.
| | - Rune Hansen
- Department of Medical Physics, Aarhus University Hospital, Denmark.
| | - Wouter Crijns
- Department of Oncology, KU Leuven, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium.
| | | | - Kenneth Poels
- Department of Oncology, KU Leuven, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium.
| | - Simon Skouboe
- Department of Oncology, Aarhus University Hospital, Denmark.
| | - Karin Haustermans
- Department of Oncology, KU Leuven, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium.
| | - Per Rugaard Poulsen
- Department of Oncology, Aarhus University Hospital, Denmark; Danish Center for Particle Therapy, Aarhus University Hospital, Denmark.
| | - Tom Depuydt
- Department of Oncology, KU Leuven, Belgium; Department of Radiation Oncology, University Hospitals Leuven, Belgium.
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7
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Gainey M, Carles M, Mix M, Meyer PT, Bock M, Grosu AL, Baltas D. Biological imaging for individualized therapy in radiation oncology: part I physical and technical aspects. Future Oncol 2018. [PMID: 29521520 DOI: 10.2217/fon-2017-0464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Recently, there has been an increase in the imaging modalities available for radiotherapy planning and radiotherapy prognostic outcome: dual energy computed tomography (CT), dynamic contrast enhanced CT, dynamic contrast enhanced magnetic resonance imaging (MRI), diffusion-weighted MRI, positron emission tomography-CT, dynamic contrast enhanced ultrasound, MR spectroscopy and positron emission tomography-MR. These techniques enable more precise gross tumor volume definition than CT alone and moreover allow subvolumes within the gross tumor volume to be defined which may be given a boost dose or an individual voxelized dose prescription may be derived. With increased plan complexity care must be taken to immobilize the patient in an accurate and reproducible manner. Moreover the physical and technical limitations of the entire treatment planning chain need to be well characterized and understood, interdisciplinary collaboration ameliorated (physicians and physicists within nuclear medicine, radiology and radiotherapy) and image protocols standardized.
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Affiliation(s)
- Mark Gainey
- Department of Radiation Oncology, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany.,German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany
| | - Montserrat Carles
- Department of Radiation Oncology, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany.,German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany
| | - Michael Mix
- German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany.,Department of Nuclear Medicine, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany
| | - Philipp T Meyer
- German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany.,Department of Nuclear Medicine, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany
| | - Michael Bock
- German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany.,Radiology - Medical Physics, Department of Radiology, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany
| | - Anca-Ligia Grosu
- Department of Radiation Oncology, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany.,German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany
| | - Dimos Baltas
- Department of Radiation Oncology, Faculty of Medicine, Medical Center, University of Freiburg, D-79106 Germany.,German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DFKZ), Heidelberg, D-69120 Germany
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8
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Ramm D. A fast dual wavelength laser beam fluid-less optical CT scanner for radiotherapy 3D gel dosimetry I: design and development. Phys Med Biol 2018; 63:045019. [PMID: 29363617 DOI: 10.1088/1361-6560/aaaa45] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three dimensional dosimetry by optical CT readout of radiosensitive gels or solids has previously been indicated as a solution for measurement of radiotherapy 3D dose distributions. The clinical uptake of these dosimetry methods has been limited, partly due to impracticalities of the optical readout such as the expertise and labour required for refractive index fluid matching. In this work a fast laser beam optical CT scanner is described, featuring fluid-less and dual wavelength operation. A second laser with a different wavelength is used to provide an alternative reference scan to the commonly used pre-irradiation scan. Transmission data for both wavelengths is effectively acquired simultaneously, giving a single scan process. Together with the elimination of refractive index fluid matching issues, scanning practicality is substantially improved. Image quality and quantitative accuracy were assessed for both dual and single wavelength methods. The dual wavelength scan technique gave improvements in uniformity of reconstructed optical attenuation coefficients in the sample 3D volume. This was due to a reduction of artefacts caused by scan to scan changes. Optical attenuation measurement accuracy was similar for both dual and single wavelength modes of operation. These results established the basis for further work on dosimetric performance.
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Affiliation(s)
- Daniel Ramm
- Department of Medical Physics, Royal Adelaide Hospital Cancer Centre, South Australia, Australia. School of Physical Sciences, University of Adelaide, South Australia, Australia
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9
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Kaplan LP, Høye EM, Balling P, Muren LP, Petersen JBB, Poulsen PR, Yates ES, Skyt PS. Determining the mechanical properties of a radiochromic silicone-based 3D dosimeter. Phys Med Biol 2017; 62:5612-5622. [PMID: 28467323 DOI: 10.1088/1361-6560/aa70cd] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
New treatment modalities in radiotherapy (RT) enable delivery of highly conformal dose distributions in patients. This creates a need for precise dose verification in three dimensions (3D). A radiochromic silicone-based 3D dosimetry system has recently been developed. Such a dosimeter can be used for dose verification in deformed geometries, which requires knowledge of the dosimeter's mechanical properties. In this study we have characterized the dosimeter's elastic behaviour under tensile and compressive stress. In addition, the dose response under strain was determined. It was found that the dosimeter behaved as an incompressible hyperelastic material with a non-linear stress/strain curve and with no observable hysteresis or plastic deformation even at high strains. The volume was found to be constant within a 2% margin at deformations up to 60%. Furthermore, it was observed that the dosimeter returned to its original geometry within a 2% margin when irradiated under stress, and that the change in optical density per centimeter was constant regardless of the strain during irradiation. In conclusion, we have shown that this radiochromic silicone-based dosimeter's mechanical properties make it a viable candidate for dose verification in deformable 3D geometries.
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Affiliation(s)
- L P Kaplan
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
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10
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Abedi I, Tavakkoli MB, Jabbari K, Amouheidari A, Yadegarfard G. Dosimetric and Radiobiological Evaluation of Multiparametric MRI-Guided Dose Painting in Radiotherapy of Prostate Cancer. JOURNAL OF MEDICAL SIGNALS AND SENSORS 2017; 7:114-121. [PMID: 28553585 PMCID: PMC5437763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Radiotherapy is one of the treatment options for locally advanced prostate cancer; however, with standard radiation doses, it is not always very effective. One of the strategies to improve the efficiency of radiotherapy is increasing the dose. In this study, to increase tumor local control rates, a new radiotherapy method, known as dose painting (DP), was investigated. To compare 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) plans with DP for prostate cancer. Twenty-four consecutive patients with locally advanced prostate cancer who underwent an multiparametric-magnetic resonance imaging (MP-MRI) (T2w, diffusion weighted image, dynamic contrast enhancement, and MRS) scan before a diagnostic biopsy from September 2015 to April 2016 were invited to take part in this study. The tumor local control probability (TCP) values for 3D-CRT, IMRT, and DP techniques were 45, 56, and 77%, respectively. The DP technique had a 37.5 and 71% higher TCP than IMRT and 3D-CRT, and these differences were statistically significant (P = 0.001). The mean normal tissue complication probability (NTCP) values of the organ at risks for 3D-CRT, IMRT, and DP showed that there were statistically significant differences among them in three plans (P = 0.01). DP by contours using MP-MRI is technically feasible. This study evaluated biological modeling based on both MP-MRI defined subvolumes and pathologically defined subvolumes. The MP-MRI-guided DP results in better TCP/NTCP than 3D-CRT and IMRT.
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Affiliation(s)
- Iraj Abedi
- Isfahan University of Medical Sciences, Isfahan, Iran
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11
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Watanabe Y, Warmington L, Gopishankar N. Three-dimensional radiation dosimetry using polymer gel and solid radiochromic polymer: From basics to clinical applications. World J Radiol 2017; 9:112-125. [PMID: 28396725 PMCID: PMC5368627 DOI: 10.4329/wjr.v9.i3.112] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/31/2016] [Accepted: 01/16/2017] [Indexed: 02/06/2023] Open
Abstract
Accurate dose measurement tools are needed to evaluate the radiation dose delivered to patients by using modern and sophisticated radiation therapy techniques. However, the adequate tools which enable us to directly measure the dose distributions in three-dimensional (3D) space are not commonly available. One such 3D dose measurement device is the polymer-based dosimeter, which changes the material property in response to radiation. These are available in the gel form as polymer gel dosimeter (PGD) and ferrous gel dosimeter (FGD) and in the solid form as solid plastic dosimeter (SPD). Those are made of a continuous uniform medium which polymerizes upon irradiation. Hence, the intrinsic spatial resolution of those dosimeters is very high, and it is only limited by the method by which one converts the dose information recorded by the medium to the absorbed dose. The current standard methods of the dose quantification are magnetic resonance imaging, optical computed tomography, and X-ray computed tomography. In particular, magnetic resonance imaging is well established as a method for obtaining clinically relevant dosimetric data by PGD and FGD. Despite the likely possibility of doing 3D dosimetry by PGD, FGD or SPD, the tools are still lacking wider usages for clinical applications. In this review article, we summarize the current status of PGD, FGD, and SPD and discuss the issue faced by these for wider acceptance in radiation oncology clinic and propose some directions for future development.
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12
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Thorwarth D, Notohamiprodjo M, Zips D, Müller AC. Personalized precision radiotherapy by integration of multi-parametric functional and biological imaging in prostate cancer: A feasibility study. Z Med Phys 2017; 27:21-30. [DOI: 10.1016/j.zemedi.2016.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/18/2015] [Accepted: 02/01/2016] [Indexed: 11/16/2022]
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13
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Høye EM, Skyt PS, Balling P, Muren LP, Taasti VT, Swakoń J, Mierzwińska G, Rydygier M, Bassler N, Petersen JBB. Chemically tuned linear energy transfer dependent quenching in a deformable, radiochromic 3D dosimeter. Phys Med Biol 2017; 62:N73-N89. [PMID: 28134130 DOI: 10.1088/1361-6560/aa512a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Most solid-state detectors, including 3D dosimeters, show lower signal in the Bragg peak than expected, a process termed quenching. The purpose of this study was to investigate how variation in chemical composition of a recently developed radiochromic, silicone-based 3D dosimeter influences the observed quenching in proton beams. The dependency of dose response on linear energy transfer, as calculated through Monte Carlo simulations of the dosimeter, was investigated in 60 MeV proton beams. We found that the amount of quenching varied with the chemical composition: peak-to-plateau ratios (1 cm into the plateau) ranged from 2.2 to 3.4, compared to 4.3 using an ionization chamber. The dose response, and thereby the quenching, was predominantly influenced by the curing agent concentration, which determined the dosimeter's deformation properties. The dose response was found to be linear at all depths. All chemical compositions of the dosimeter showed dose-rate dependency; however this was not dependent on the linear energy transfer. Track-structure theory was used to explain the observed quenching effects. In conclusion, this study shows that the silicone-based dosimeter has potential for use in measuring 3D-dose-distributions from proton beams.
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Affiliation(s)
- Ellen Marie Høye
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
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14
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Grau C, Overgaard J, Høyer M, Tanderup K, Lindegaard JC, Muren LP. Biology-guided adaptive radiotherapy (BiGART) is progressing towards clinical reality. Acta Oncol 2015; 54:1245-50. [PMID: 26390238 DOI: 10.3109/0284186x.2015.1076992] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Cai Grau
- a Department of Oncology , Aarhus University Hospital , Aarhus , Denmark
| | - Jens Overgaard
- b Department of Experimental Clinical Oncology , Aarhus University Hospital , Aarhus , Denmark
| | - Morten Høyer
- a Department of Oncology , Aarhus University Hospital , Aarhus , Denmark
| | - Kari Tanderup
- a Department of Oncology , Aarhus University Hospital , Aarhus , Denmark
- c Department of Medical Physics , Aarhus University Hospital , Aarhus , Denmark
| | | | - Ludvig Paul Muren
- a Department of Oncology , Aarhus University Hospital , Aarhus , Denmark
- c Department of Medical Physics , Aarhus University Hospital , Aarhus , Denmark
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Høye EM, Balling P, Yates ES, Muren LP, Petersen JBB, Skyt PS. Eliminating the dose-rate effect in a radiochromic silicone-based 3D dosimeter. Phys Med Biol 2015; 60:5557-70. [PMID: 26134268 DOI: 10.1088/0031-9155/60/14/5557] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Comprehensive dose verification, such as 3D dosimetry, may be required for safe introduction and use of advanced treatment modalities in radiotherapy. A radiochromic silicone-based 3D dosimetry system has recently been suggested, though its clinical use has so far been limited by a considerable dose-rate dependency of the dose response. In this study we have investigated the dose-rate dependency with respect to the chemical composition of the dosimeter. We found that this dependency was reduced with increasing dye concentration, and the dose response was observed to be identical for dosimeters irradiated with 2 and 6 Gy min(-1) at concentrations of 0.26% (w/w) dye and 1% (w/w) dye solvent. Furthermore, for the optimized dosimeter formulation, no dose-rate effect was observed due to the attenuation of the beam fluence with depth. However, the temporal stability of the dose response decreased with dye concentration; the response was reduced by (62 ± 1)% within approximately 20 h upon irradiation, at the optimal chemical composition and storage at room temperature. In conclusion, this study presents a chemical composition for a dose-rate independent silicone dosimeter which has considerably improved the clinical applicability of such dosimeters, but at the cost of a decreased stability.
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Affiliation(s)
- E M Høye
- Dept of Medical Physics, Aarhus University/Aarhus University Hospital, Aarhus, Denmark
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Skyt PS, Jensen GV, Wahlstedt I, Baltzer Petersen JB, Muren LP, Pedersen JS, Balling P. Investigation of nanoscale structures by small-angle X-ray scattering in a radiochromic dosimeter. RSC Adv 2014. [DOI: 10.1039/c3ra46605a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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