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Abtahi SMM, Habibi F. Investigation of the beam quality and dose rate dependence of PAKAG polymer gel dosimeter in optical readout technique. Biomed Phys Eng Express 2024; 10:055041. [PMID: 39151446 DOI: 10.1088/2057-1976/ad7032] [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: 04/05/2024] [Accepted: 08/16/2024] [Indexed: 08/19/2024]
Abstract
This study aims to evaluate the optical response dependence of the PAKAG polymer gel dosimeter on photon energy and dose rate. The produced gel dosimeters were irradiated using a Varian CL 21EX medical linear accelerator with delivered doses of 0, 2, 4, 6, 8, and 10 Gy. To examine the response dependence on the delivered dose rate, dose rates of 50, 100, 200, and 350 cGy min-1were investigated. Additionally, two incident beam qualities of 6 and 18 MV were examined to study the response dependence on the incident beam energy. The irradiated polymer gel dosimeters were readout using a UV-vis spectrophotometer in the 300 to 800 nm scan range. The results reveal that a wide variation in dose rate (50-350 cGy.min-1) influences the absorbance-dose response and the sensitivity of PAKAG gel. However, smaller variations did not show a significant effect on the response. Furthermore, the response changed insignificantly with beam quality for investigated energies. It was concluded that the optical reading response of the PAKAG polymer gel dosimeter is satisfactorily independent of external parameters, including dose rate and incident beam quality.
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Affiliation(s)
| | - Fatemeh Habibi
- Department of Physics, Imam Khomeini International University, Qazvin, 3414896818, Iran
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2
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Kunkyab T, Lakrad K, Jirasek A, Oldham M, Quinn B, Hyde D, Adamson J. Clinical applicability of Linac-integrated CBCT based NIPAM 3D dosimetry: a dual-institutional investigation. Phys Med Biol 2024; 69:155002. [PMID: 38959910 DOI: 10.1088/1361-6560/ad5eef] [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: 11/18/2023] [Accepted: 07/03/2024] [Indexed: 07/05/2024]
Abstract
Objective.To develop and benchmark a novel 3D dose verification technique consisting of polymer gel dosimetry (PGD) with cone-beam-CT (CBCT) readout through a two-institution study. The technique has potential for wide and robust applicability through reliance on CBCT readout.Approach. Three treatment plans (3-field, TG119-C-shape spine, 4-target SRS) were created by two independent institutions (Institutions A and B). A Varian Truebeam linear accelerator was used to deliver the plans to NIPAM polymer gel dosimeters produced at both institutions using an identical approach. For readout, a slow CBCT scan mode was used to acquire pre- and post-irradiation images of the gel (1 mm slice thickness). Independent gel analysis tools were used to process the PGD images (A: VistaAce software, B: in-house MATLAB code). Comparing planned and measured doses, the analysis involved a combination of 1D line profiles, 2D contour plots, and 3D global gamma maps (criteria ranging between 2%1 mm and 5%2 mm, with a 10% dose threshold).Main results. For all gamma criteria tested, the 3D gamma pass rates were all above 90% for 3-field and 88% for the SRS plan. For the C-shape spine plan, we benchmarked our 2% 2 mm result against previously published work using film analysis (93.4%). For 2%2 mm, 99.4% (Institution A data), and 89.7% (Institution B data) were obtained based on VistaAce software analysis, 83.7% (Institution A data), and 82.9% (Institution B data) based on MATLAB.Significance. The benchmark data demonstrate that when two institutions follow the same rigorous procedures gamma passing rates up to 99%, for 2%2 mm criteria can be achieved for substantively different treatment plans. The use of different software and calibration techniques may have contributed to the variation in the 3D gamma results. By sharing the data across institutions, we observe the gamma passing rate is more consistent within each pipeline, indicating the need for standardized analysis methods.
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Affiliation(s)
- Tenzin Kunkyab
- Department of Physics, University of British Columbia-Okanagan Campus, Kelowna, British Columbia, Canada
- BC Cancer Center, Kelowna, British Columbia
| | - Kawtar Lakrad
- Department of Physics, Hassan II University, Casablanca, Morocco
- Duke University Medical Center, Durham, NC
| | - Andrew Jirasek
- Department of Physics, University of British Columbia-Okanagan Campus, Kelowna, British Columbia, Canada
| | | | - Benjamin Quinn
- Modus Medical Devices Inc./IBA Dosimetry, London, Ontario, Canada
| | - Derek Hyde
- Department of Physics, University of British Columbia-Okanagan Campus, Kelowna, British Columbia, Canada
- BC Cancer Center, Kelowna, British Columbia
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Rabaeh KA, Qawouq RKA, Eyadeh MM, Shatnawi MTM. Optimizing the feasibility of polyvinyl alcohol-potassium iodine gel for medical dosimeter. Biomed Phys Eng Express 2024; 10:055006. [PMID: 38955138 DOI: 10.1088/2057-1976/ad5db0] [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: 01/27/2024] [Accepted: 07/02/2024] [Indexed: 07/04/2024]
Abstract
This work aims to improve the post stabilty of reusable potassium iodide hydrogel dosimter. A reusable and low-cost radiochromic dosimeter containing a gel matrix of polyvinyl alcohol, potassium iodide dye, froctose as reducing agent and glutaraldehyde as cross-linking agent was developed for dose calibration in radiotherapy. The gel samples were exposed to different absorbed doses using a medical linear acceleration. UV-vis Spectrophotometry was utilized to investigate the changes in optical-properties of irradiated gels with regard to peak wavelength of 353 nm. The stability of the gel (one of the most limitation of using this dosimeter) was improved significantly by the addition of certain concentrations of dimethyl sulfoxide. The two-dimensional optical imaging system of charge-coupled-device (CCD) camera with a uniform RGB light-emitting-diode (LED) array source was used for diffusion coefficient purpose using two dimensional gel template. The value of diffusion coefficient reported is significant and highly reduced compared with other dosimeters reported in the literatures. Moreover, heating the improved gels to certain temperatures results in resetting their optical properties, which makes it possible to reuse for multiple times.
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Affiliation(s)
- Khalid A Rabaeh
- Medical Imaging Department, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, 13115, Jordan
| | - Ruba K A Qawouq
- Physics Department, School of Science, The University of Jordan, Amman, 11942, Jordan
| | - Molham M Eyadeh
- Physics Department, Faculty of Science, Yarmouk University, Irbid, 21163, Jordan
| | - Moneeb T M Shatnawi
- Physics Department, School of Science, The University of Jordan, Amman, 11942, Jordan
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Silveira MA, Pavoni JF, Baffa O. A cone-beam optical CT based on a convergent light source - Characterization and optimization. Phys Med 2024; 123:103415. [PMID: 38901143 DOI: 10.1016/j.ejmp.2024.103415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/18/2024] [Accepted: 06/16/2024] [Indexed: 06/22/2024] Open
Abstract
PURPOSE Employing a Fresnel lens and a point-like light source to create a convergent light beam for the camera effectively minimizes stray light and enhances image quality in optical computed tomography (OCT), benefiting 3D dosimetry applications. This study outlines the development of an economical cone-beam optical computed scanner for 3D dosimetry. METHODS Optical performance was assessed by calculating modulation transfer function (MTF) with pattern charts. Stray light was evaluated by imaging a cylinder flask and a square grid with 5 mm diameter holes to determine the stray-to-primary ratio. Reconstruction quality was determined using SIRT-TV and compared with spectrophotometry attenuation coefficients, with the best regularization parameter (λ = 0.01) chosen based on contrast-to-noise ratio (CNR). Dosimetry performance was assessed by determining percentage dose depth (PDD) for a 6MV beam with a 5 × 5 cm2 field using FXO-f gel dosimeter, compared with ionization chamber data. RESULTS MTF evaluation yielded ≥ 50 % agreement with pattern charts. Stray-to-primary ratio was less than 0.1 or 10 % of the total signal. Reconstruction showed low noise and artifacts, with optimal CNR at λ = 0.01. Attenuation coefficients from optical CT aligned with spectrometer measurements within 1.2 %. PDD calculated with FXO-f gel dosimeter closely matched ionization chamber data (<1.2 % difference), achieving a dose resolution of 0.1 Gy. CONCLUSION The built and optimization the de optical-CT based on a convergent beam is read to perform the 3D quality assurance in clinical applications.
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Affiliation(s)
- M A Silveira
- Departamento de Física, FFCLRP, University of São Paulo-USP, Ribeirão Preto, SP, Brazil.
| | - J F Pavoni
- Departamento de Física, FFCLRP, University of São Paulo-USP, Ribeirão Preto, SP, Brazil
| | - O Baffa
- Departamento de Física, FFCLRP, University of São Paulo-USP, Ribeirão Preto, SP, Brazil
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Carlier B, Heymans SV, Nooijens S, Collado-Lara G, Toumia Y, Delombaerde L, Paradossi G, D’hooge J, Van Den Abeele K, Sterpin E, Himmelreich U. A Preliminary Investigation of Radiation-Sensitive Ultrasound Contrast Agents for Photon Dosimetry. Pharmaceuticals (Basel) 2024; 17:629. [PMID: 38794199 PMCID: PMC11125270 DOI: 10.3390/ph17050629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/28/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024] Open
Abstract
Radiotherapy treatment plans have become highly conformal, posing additional constraints on the accuracy of treatment delivery. Here, we explore the use of radiation-sensitive ultrasound contrast agents (superheated phase-change nanodroplets) as dosimetric radiation sensors. In a series of experiments, we irradiated perfluorobutane nanodroplets dispersed in gel phantoms at various temperatures and assessed the radiation-induced nanodroplet vaporization events using offline or online ultrasound imaging. At 25 °C and 37 °C, the nanodroplet response was only present at higher photon energies (≥10 MV) and limited to <2 vaporization events per cm2 per Gy. A strong response (~2000 vaporizations per cm2 per Gy) was observed at 65 °C, suggesting radiation-induced nucleation of the droplet core at a sufficiently high degree of superheat. These results emphasize the need for alternative nanodroplet formulations, with a more volatile perfluorocarbon core, to enable in vivo photon dosimetry. The current nanodroplet formulation carries potential as an innovative gel dosimeter if an appropriate gel matrix can be found to ensure reproducibility. Eventually, the proposed technology might unlock unprecedented temporal and spatial resolution in image-based dosimetry, thanks to the combination of high-frame-rate ultrasound imaging and the detection of individual vaporization events, thereby addressing some of the burning challenges of new radiotherapy innovations.
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Affiliation(s)
- Bram Carlier
- Department of Oncology, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (B.C.); (L.D.); (E.S.)
- Department of Imaging and Pathology, KU Leuven-University of Leuven, 3000 Leuven, Belgium
- Molecular Small Animal Imaging Center (MoSAIC), KU Leuven-University of Leuven, 3000 Leuven, Belgium
| | - Sophie V. Heymans
- Department of Physics, KU Leuven Campus Kortrijk—KULAK, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium; (S.V.H.); (K.V.D.A.)
- Department of Cardiovascular Sciences, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (S.N.); (J.D.)
| | - Sjoerd Nooijens
- Department of Cardiovascular Sciences, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (S.N.); (J.D.)
| | - Gonzalo Collado-Lara
- Department of Cardiology, Erasmus MC University Medical Center, 3015 GD Rotterdam, The Netherlands;
| | - Yosra Toumia
- National Institute for Nuclear Physics, INFN Sezione di Roma Tor Vergata, 00133 Rome, Italy;
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Laurence Delombaerde
- Department of Oncology, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (B.C.); (L.D.); (E.S.)
- Department of Radiotherapy, UH Leuven, 3000 Leuven, Belgium
| | - Gaio Paradossi
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Jan D’hooge
- Department of Cardiovascular Sciences, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (S.N.); (J.D.)
| | - Koen Van Den Abeele
- Department of Physics, KU Leuven Campus Kortrijk—KULAK, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium; (S.V.H.); (K.V.D.A.)
| | - Edmond Sterpin
- Department of Oncology, KU Leuven-University of Leuven, 3000 Leuven, Belgium; (B.C.); (L.D.); (E.S.)
- Particle Therapy Interuniversity Center Leuven—PARTICLE, 3000 Leuven, Belgium
| | - Uwe Himmelreich
- Department of Imaging and Pathology, KU Leuven-University of Leuven, 3000 Leuven, Belgium
- Molecular Small Animal Imaging Center (MoSAIC), KU Leuven-University of Leuven, 3000 Leuven, Belgium
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Collins S, Ogilvy A, Hare W, Hilts M, Jirasek A. Iterative image reconstruction algorithm analysis for optical CT radiochromic gel dosimetry. Biomed Phys Eng Express 2024; 10:035031. [PMID: 38579691 DOI: 10.1088/2057-1976/ad3afe] [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: 12/22/2023] [Accepted: 04/05/2024] [Indexed: 04/07/2024]
Abstract
Background.Modern radiation therapy technologies aim to enhance radiation dose precision to the tumor and utilize hypofractionated treatment regimens. Verifying the dose distributions associated with these advanced radiation therapy treatments remains an active research area due to the complexity of delivery systems and the lack of suitable three-dimensional dosimetry tools. Gel dosimeters are a potential tool for measuring these complex dose distributions. A prototype tabletop solid-tank fan-beam optical CT scanner for readout of gel dosimeters was recently developed. This scanner does not have a straight raypath from source to detector, thus images cannot be reconstructed using filtered backprojection (FBP) and iterative techniques are required.Purpose.To compare a subset of the top performing algorithms in terms of image quality and quantitatively determine the optimal algorithm while accounting for refraction within the optical CT system. The following algorithms were compared: Landweber, superiorized Landweber with the fast gradient projection perturbation routine (S-LAND-FGP), the fast iterative shrinkage/thresholding algorithm with total variation penalty term (FISTA-TV), a monotone version of FISTA-TV (MFISTA-TV), superiorized conjugate gradient with the nonascending perturbation routine (S-CG-NA), superiorized conjugate gradient with the fast gradient projection perturbation routine (S-CG-FGP), superiorized conjugate gradient with with two iterations of CG performed on the current iterate and the nonascending perturbation routine (S-CG-2-NA).Methods.A ray tracing simulator was developed to track the path of light rays as they traverse the different mediums of the optical CT scanner. Two clinical phantoms and several synthetic phantoms were produced and used to evaluate the reconstruction techniques under known conditions. Reconstructed images were analyzed in terms of spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), signal non-uniformity (SNU), mean relative difference (MRD) and reconstruction time. We developed an image quality based method to find the optimal stopping iteration window for each algorithm. Imaging data from the prototype optical CT scanner was reconstructed and analysed to determine the optimal algorithm for this application.Results.The optimal algorithms found through the quantitative scoring metric were FISTA-TV and S-CG-2-NA. MFISTA-TV was found to behave almost identically to FISTA-TV however MFISTA-TV was unable to resolve some of the synthetic phantoms. S-CG-NA showed extreme fluctuations in the SNR and CNR values. S-CG-FGP had large fluctuations in the SNR and CNR values and the algorithm has less noise reduction than FISTA-TV and worse spatial resolution than S-CG-2-NA. S-LAND-FGP had many of the same characteristics as FISTA-TV; high noise reduction and stability from over iterating. However, S-LAND-FGP has worse SNR, CNR and SNU values as well as longer reconstruction time. S-CG-2-NA has superior spatial resolution to all algorithms while still maintaining good noise reduction and is uniquely stable from over iterating.Conclusions.Both optimal algorithms (FISTA-TV and S-CG-2-NA) are stable from over iterating and have excellent edge detection with ESF MTF 50% values of 1.266 mm-1and 0.992 mm-1. FISTA-TV had the greatest noise reduction with SNR, CNR and SNU values of 424, 434 and 0.91 × 10-4, respectively. However, low spatial resolution makes FISTA-TV only viable for large field dosimetry. S-CG-2-NA has better spatial resolution than FISTA-TV with PSF and LSF MTF 50% values of 1.581 mm-1and 0.738 mm-1, but less noise reduction. S-CG-2-NA still maintains good SNR, CNR, and SNU values of 168, 158 and 1.13 × 10-4, respectively. Thus, S-CG-2-NA is a well rounded reconstruction algorithm that would be the preferable choice for small field dosimetry.
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Affiliation(s)
- Steve Collins
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Andy Ogilvy
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Warren Hare
- Dept. Mathematics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Michelle Hilts
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
- Medical Physics, BC Cancer-Kelowna, Kelowna BC V1Y 5L3, Canada
| | - Andrew Jirasek
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
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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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Kozicki M, Sąsiadek-Andrzejczak E, Wach R, Maras P. Flexible Cotton Fabric-Based Ionizing Radiation Dosimeter for 2D Dose Distribution Measurements over a Wide Dose Range at High Dose Rates. Int J Mol Sci 2024; 25:2916. [PMID: 38474163 DOI: 10.3390/ijms25052916] [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: 02/08/2024] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
This work presents an ecological, flexible 2D radiochromic dosimeter for measuring ionizing radiation in the kilogray dose range. Cotton woven fabric made of cellulose was volume-modified with nitrotetrazolium blue chloride as a radiation-sensitive compound. Its features include a color change during exposure from yellowish to purple-brown and flexibility that allows it to adapt to various shapes. It was found that (i) the dose response is up to ~80 kGy, (ii) it is independent of the dose rate for 1.1-73.1 kGy/min, (iii) it can be measured in 2D using a flatbed scanner, (iv) the acquired images can be filtered using a mean filter, which improves its dose resolution, (v) the dose resolution is -0.07 to -0.4 kGy for ~0.6 to ~75.7 kGy for filtered images, and (vi) two linear dose subranges can be distinguished: ~0.6 to ~7.6 kGy and ~9.9 to ~62.0 kGy. The dosimeter combined with flatbed scanner reading and data processing using dedicated software packages constitutes a comprehensive system for measuring dose distributions for objects with complex shapes.
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Affiliation(s)
- Marek Kozicki
- Department of Mechanical Engineering, Informatics and Chemistry of Polymer Materials, Faculty of Materials Technologies and Textile Design, Lodz University of Technology, Żeromskiego 116, 90-543 Lodz, Poland
| | - Elżbieta Sąsiadek-Andrzejczak
- Department of Mechanical Engineering, Informatics and Chemistry of Polymer Materials, Faculty of Materials Technologies and Textile Design, Lodz University of Technology, Żeromskiego 116, 90-543 Lodz, Poland
| | - Radosław Wach
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Wroblewskiego 15, 93-590 Lodz, Poland
| | - Piotr Maras
- Department of Radiotherapy Planning, Copernicus Hospital, Pabianicka 62, 93-513 Lodz, Poland
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9
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Ceberg S, Olding T, Baldock C. Gel dosimetry has a viable future for dosimetry in the radiation oncology clinic. Phys Eng Sci Med 2024; 47:1-5. [PMID: 38112936 DOI: 10.1007/s13246-023-01365-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Affiliation(s)
- Sofie Ceberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Tim Olding
- Cancer Centre of Southeastern Ontario at Kingston Health Sciences Centre, Kingston, Canada
- Department of Physics, Queen's University, Kingston, Canada
- Department of Oncology, Queen's University, Kingston, Canada
| | - Clive Baldock
- Graduate Research School, Western Sydney University, Penrith, NSW, 2747, Australia.
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10
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Jensen ML, Julsgaard B, Turtos RM, Skyt PS, Jensen MB, Muren LP, Balling P. High-resolution three-dimensional dosimetry in clinically relevant volumes utilizing optically stimulated luminescence. Med Phys 2024; 51:2200-2209. [PMID: 37929802 DOI: 10.1002/mp.16796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 08/29/2023] [Accepted: 09/21/2023] [Indexed: 11/07/2023] Open
Abstract
BACKGROUND The continued development of new radiotherapy techniques requires dosimetry systems that satisfy increasingly rigorous requirements, such as high sensitivity, wide dose range, and high spatial resolution. An emerging requirement is the ability to read out doses in three dimensions (3D) with high precision and spatial resolution. A few dosimetry systems with 3D capabilities are available, but their application in a clinical workflow is limited for various reasons, primarily originating from their chemical nature. The search for a 3D dosimetry system with potential for clinical implementation is thus ongoing. PURPOSE To demonstrate the capabilities of a novel optically-stimulated-luminescence (OSL)-based 3D dosimetry system capable of measuring radiation doses in clinically relevant volumes. METHODS A laser-based readout system was used to measure dose distributions delivered by both photons and protons, utilizing the OSL from a50 × 50 × 50 $50\times 50\times 50$ mm3 $^3$ YSO:Ce crystal. A homogeneous treatment plan consisting of two opposing photon fields was used to establish an inhomogeneity correction map of the crystal response and demonstrated the accuracy and precision of the system. The crystal was additionally irradiated with a photon treatment plan consisting of three overlapping10 × 10 $10\times 10$ mm2 $^2$ fields delivered from different angles, and a proton treatment plan consisting of four pencil beams with energies 90 MeV (× 2 $\times 2$ ), 115 MeV, and 140 MeV. The system abilities were quantified by comparing the 3D-resolved measurements to Monte Carlo simulations. RESULTS The dose map reproducibility of the system was found to be within 2% including both statistical and systematic errors. The measurements yielded integrated doses from a volume of50 × 50 × 40 $50\times 50\times 40$ mm3 $^3$ with voxel volumes of just0.28 × 0.28 × 0.50 $0.28\times 0.28\times 0.50$ mm3 $^3$ . An excellent agreement between the 3D-resolved measurements and the simulations was found for both photon- and proton-irradiation. CONCLUSIONS The capabilities of the devised system for measuring clinically relevant fields of photons and proton pencil beams within a clinically relevant volume were demonstrated. The system poses as a promising candidate for clinical applications, and enables future research in the field of OSL-based tissue-equivalent 3D dosimetry.
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Affiliation(s)
- Mads L Jensen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Brian Julsgaard
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Rosana M Turtos
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Peter S Skyt
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Morten B Jensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | - Ludvig P Muren
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Peter Balling
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
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Lee M, Noh S, Shin JB, Kwak J, Jeong C. Evaluation of Fused Deposition Modeling Materials for 3D-Printed Container of Dosimetric Polymer Gel. Gels 2024; 10:146. [PMID: 38391476 PMCID: PMC10888196 DOI: 10.3390/gels10020146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
Accurate dosimetric verification is becoming increasingly important in radiotherapy. Although polymer gel dosimetry may be useful for verifying complex 3D dose distributions, it has limitations for clinical application due to its strong reactivity with oxygen and other contaminants. Therefore, it is important that the material of the gel storage container blocks reaction with external contaminants. In this study, we tested the effect of air and the chemical permeability of various polymer-based 3D printing materials that can be used as gel containers. A methacrylic acid, gelatin, and tetrakis (hydroxymethyl) phosphonium chloride gel was used. Five types of printing materials that can be applied to the fused deposition modeling (FDM)-type 3D printer were compared: acrylonitrile butadiene styrene (ABS), co-polyester (CPE), polycarbonate (PC), polylactic acid (PLA), and polypropylene (PP) (reference: glass vial). The map of R2 (1/T2) relaxation rates for each material, obtained from magnetic resonance imaging scans, was analyzed. Additionally, response histograms and dose calibration curves from the R2 map were evaluated. The R2 distribution showed that CPE had sharper boundaries than the other materials, and the profile gradient of CPE was also closest to the reference vial. Histograms and dose calibration showed that CPE provided the most homogeneous and the highest relative response of 83.5%, with 8.6% root mean square error, compared with the reference vial. These results indicate that CPE is a reasonable material for the FDM-type 3D printing gel container.
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Affiliation(s)
- Minsik Lee
- Department of Radiation Oncology, Kangwon National University Hospital, 157 Baengnyeong-ro, Chuncheon-si 24290, Republic of Korea
| | - Seonyeong Noh
- Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Jun-Bong Shin
- Department of Radiation Oncology, Kangwon National University Hospital, 157 Baengnyeong-ro, Chuncheon-si 24290, Republic of Korea
| | - Jungwon Kwak
- Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Chiyoung Jeong
- Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
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12
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Liu B, Haithem Zaki S, García E, Bonilla A, Thabit D, Hussein Adab A. The investigation of dose rate and photon beam energy dependence of optimized PASSAG polymer gel dosimeter using magnetic resonance imaging. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2024; 32:751-764. [PMID: 38217634 DOI: 10.3233/xst-230282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
OBJECTIVE It seems that dose rate (DR) and photon beam energy (PBE) may influence the sensitivity and response of polymer gel dosimeters. In the current project, the sensitivity and response dependence of optimized PASSAG gel dosimeter (OPGD) on DR and PBE were assessed. MATERIALS AND METHODS We fabricated the OPGD and the gel samples were irradiated with various DRs and PBEs. Then, the sensitivity and response (R2) of OPGD were obtained by MRI at various doses and post-irradiation times. RESULTS Our analysis showed that the sensitivity and response of OPGD are not affected by the evaluated DRs and PBEs. It was also found that the dose resolution values of OPGD ranged from 9 to 33 cGy and 12 to 34 cGy for the evaluated DRs and PBEs, respectively. Additionally, the data demonstrated that the sensitivity and response dependence of OPGD on DR and PBE do not vary over various times after the irradiation. CONCLUSIONS The findings of this research project revealed that the sensitivity and response dependence of OPGD are independent of DR and PBE.
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Affiliation(s)
- Bo Liu
- Magnetic Resonance Imaging Room, Henan Province Hospital of Traditional Chinese Medicine, Zhengzhou, China
| | - Shaima Haithem Zaki
- Department of Anesthesia Techniques, Al-Noor University College, Nineveh, Iraq
| | - Eduardo García
- Facultad de Mecánica, Escuela Superior Politécnica de Chimborazo (ESPOCH), Riobamba, Ecuador
| | - Amanda Bonilla
- Facultad de Ciencias, Escuela Superior Politécnica de Chimborazo (ESPOCH), Sede Orellana, El Coca, Ecuador
| | - Daha Thabit
- Medical Technical College, Al-Farahidi University, Baghdad, Iraq
| | - Aya Hussein Adab
- Department of Pharmacy, Al-Zahrawi University College, Karbala, Iraq
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13
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Wegener S, Abu Rashed R, Sauer OA, Razinskas G. Sensitivity and specificity of secondary dose calculation for head and neck treatment plans. J Appl Clin Med Phys 2023; 24:e14139. [PMID: 37690124 PMCID: PMC10691627 DOI: 10.1002/acm2.14139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/10/2023] [Accepted: 08/16/2023] [Indexed: 09/12/2023] Open
Abstract
PURPOSE Secondary dose calculation (SDC) with an independent algorithm is one option to perform plan-specific quality assurance (QA). While measurement-based QA can potentially detect errors in plan delivery, the dose values are typically only compared to calculations on homogeneous phantom geometries instead of patient CT data. We analyzed the sensitivity and specificity of an SDC software by purposely introducing different errors and determined thresholds for optimal decisions. METHODS Thirty head and neck VMAT plans and 30 modifications of those plans, including errors related to density and beam modelling, were recalculated using RadCalc with a Monte Carlo algorithm. Decision thresholds were obtained by receiver operating characteristics (ROC) analysis. For comparison, measurement-based QA using the ArcCHECK phantom was carried out and evaluated in the same way. RESULTS Despite optimized decision thresholds, none of the systems was able to reliably detect all errors. ArcCHECK analysis using a 2%/2 mm criterion with a threshold of 91.1% had an area under the curve (AUC) of 0.80. Evaluating differences in recalculated and planned DVH parameter of the target structures in RadCalc with a 2% threshold an AUC of 0.86 was achieved. Out-of-field deviations could be attributed to weaknesses in the beam model. CONCLUSIONS Secondary dose calculation with RadCalc is an alternative to established measurement-based phantom QA. Different tools catch different errors; therefore, a combination of approaches should be preferred.
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Affiliation(s)
- Sonja Wegener
- University Hospital WurzburgDepartment of Radiation OncologyWuerzburgGermany
| | - Ruaa Abu Rashed
- University Hospital WurzburgDepartment of Radiation OncologyWuerzburgGermany
- Ernst‐Abbe‐Hochschule JenaJenaGermany
| | - Otto A. Sauer
- University Hospital WurzburgDepartment of Radiation OncologyWuerzburgGermany
| | - Gary Razinskas
- University Hospital WurzburgDepartment of Radiation OncologyWuerzburgGermany
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14
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Sevcik A, Rinkevicius Z, Adliene D. Radiation-Driven Polymerisation of Methacrylic Acid in Aqueous Solution: A Chemical Events Monte Carlo Study. Gels 2023; 9:947. [PMID: 38131933 PMCID: PMC10742901 DOI: 10.3390/gels9120947] [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: 11/12/2023] [Revised: 11/24/2023] [Accepted: 11/26/2023] [Indexed: 12/23/2023] Open
Abstract
This study employed a coarse-grained Monte Carlo (MC) simulation to investigate the radiation-induced polymerisation of methacrylic acid (MAA) in an aqueous solution. This method provides an alternative to traditional kinetic models, enabling a detailed examination of the micro-structure and growth patterns of MAA polymers, which are often not captured in other approaches. In this work, we generated multiple clones of a simulation box, each containing a specific chemical composition. In these simulations, every coarse-grained (CG) bead represents an entire monomer. The growth function, defined by the chemical behaviour of interacting substances, was determined through repeated random sampling. This approach allowed us to simulate the complex process of radiation-induced polymerisation, enhancing our understanding of the formation of poly(methacrylic acid) hydrogels at a microscopic level; while Monte Carlo simulations have been applied in various contexts of polymerisation, this study's specific approach to modelling the radiation-induced polymerisation of MAA in an aqueous environment, utilising the data obtained by quantum chemistry modelling, with an emphasis on micro-structural growth, has not been extensively explored in existing studies. This understanding is important for advancing the synthesis of these hydrogels, which have potential applications in diverse fields such as materials science and medicine.
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Affiliation(s)
- Aleksandras Sevcik
- Department of Physics, Kaunas University of Technology, Studentu 50, 51368 Kaunas, Lithuania;
| | - Zilvinas Rinkevicius
- Department of Physics, Kaunas University of Technology, Studentu 50, 51368 Kaunas, Lithuania;
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, Brinellvägen 8, 11428 Stockholm, Sweden
| | - Diana Adliene
- Department of Physics, Kaunas University of Technology, Studentu 50, 51368 Kaunas, Lithuania;
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15
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Collins S, Ogilvy A, Huang D, Hare W, Hilts M, Jirasek A. Iterative image reconstruction with polar coordinate discretized system matrix for optical CT radiochromic gel dosimetry. Med Phys 2023; 50:6334-6353. [PMID: 37190786 DOI: 10.1002/mp.16459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/30/2023] [Accepted: 04/16/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Gel dosimeters are a potential tool for measuring the complex dose distributions that characterize modern radiotherapy. A prototype tabletop solid-tank fan-beam optical CT scanner for readout of gel dosimeters was recently developed. This scanner does not have a straight raypath from source to detector, thus images cannot be reconstructed using filtered backprojection (FBP) and iterative techniques are required. Iterative image reconstruction requires a system matrix that describes the geometry of the imaging system. Stored system matrices can become immensely large, making them impractical for storage on a typical desktop computer. PURPOSE Here we develop a method to reduce the storage size of optical CT system matrices through use of polar coordinate discretization while accounting for the refraction in optical CT systems. METHODS A ray tracing simulator was developed to track the path of light rays as they traverse the different mediums of the optical CT scanner. Cartesian coordinate discretized system matrices (CCDSMs) and polar coordinate discretized system matrices (PCDSMs) were generated by discretizing the reconstruction area of the optical CT scanner into a Cartesian pixel grid and a polar coordinate pixel grid, respectively. The length of each ray through each pixel was calculated and used to populate the system matrices. To ensure equal weighting during iterative reconstruction, the radial rings of PCDSMs were asymmetrically spaced such that the area of each polar pixel was constant. Two clinical phantoms and several synthetic phantoms were produced and used to evaluate the reconstruction techniques under known conditions. Reconstructed images were analyzed in terms of spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), signal nonuniformity (SNU), and Gamma map pass percentage. RESULTS A storage size reduction of 99.72% was found when comparing a PCDSM to a CCDSM with the same total number of pixels. Images reconstructed with a PCDSM were found to have superior SNR, CNR, SNU, and Gamma (1 mm, 1%) pass percentage compared to those reconstructed with a CCDSM. Increasing spatial resolution in the radial direction with increasing radial distance was found in both PCDSM and CCDSM reconstructions due to the outer regions refracting light more severely. Images reconstructed with a PCDSM showed a decrease in spatial resolution in the azimuthal directions as radial distance increases, due to the widening of the polar pixels. However, this can be mitigated with only a slight increase in storage size by increasing the number of projections. A loss of spatial resolution in the radial direction within 5 mm radially from center was found when reconstructing with a PCDSM, due to the large innermost pixels. However, this was remedied by increasing the number of radial rings within the PCDSM, yielding radial spatial resolution on par with images reconstructed with a CCDSM and a storage size reduction of 99.26%. CONCLUSIONS Discretizing the image pixel elements in polar coordinates achieved a system matrix storage size reduction of 99.26% with only minimal reduction in the image quality.
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Affiliation(s)
- Steve Collins
- Department of Physics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Andy Ogilvy
- Department of Physics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Dominic Huang
- Department of Mathematics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Warren Hare
- Department of Mathematics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Michelle Hilts
- Department of Physics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
- Medical Physics, BC Cancer-Kelowna, Kelowna, British Columbia, Canada
| | - Andrew Jirasek
- Department of Physics, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
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16
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Maeyama T, Hayashi K, Watanabe Y, Ohara M, Nakagawa S. Development of a silicone-based radio-fluorogenic dosimeter using dihydrorhodamine 6G. Phys Med 2023; 114:102684. [PMID: 37778206 DOI: 10.1016/j.ejmp.2023.102684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/24/2023] [Accepted: 09/11/2023] [Indexed: 10/03/2023] Open
Abstract
A silicon-based three-dimensional dosimeter can be formed in a free shape without a container and deformed because of its flexibility. Several studies have focused on enhancing its radiological characteristics and assessing its applicability as a quality assurance tool for image-guided and adaptive radiation therapy, considering motion and deformation. Here, we applied a fluorescence probe (dihydrorhodamine 6G, DHR6G) to a silicon elastomer as a new radiosensitive compound that converts nonfluorescent into fluorescent dyes using irradiation, and its fluorescence intensity increases linearly with the absorbed dose. In this study, we demonstrated a cost-effective synthesis method and optimized the composition conditions. The results showed that the DHR6G-SE prepared from 2.2 × 10-3 wt% DHR6G, 0.024 wt% pyridine, and a silicone elastomer (SE) (SILPOT TM 184, base/curing agent = 10/1) exhibited a linear increase in fluorescence with radiation exposure within a dose range of 0-8 Gy and a highly stable sensitivity for as long as 64 h. To demonstrate its container-less characteristics, the possibility of dosimetry for low-energy X-rays using DHR6G-SE was investigated.
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Affiliation(s)
- Takuya Maeyama
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan; RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
| | - Kiichiro Hayashi
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Yusuke Watanabe
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Maki Ohara
- National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-City, Chiba 263-8555, Japan
| | - Seiko Nakagawa
- Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064, Japan
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17
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Magugliani G, Marranconi M, Liosi GM, Locatelli F, Gambirasio A, Trombetta L, Hertsyk V, Torri V, Galluccio F, Macerata E, Mossini E, Santi A, Mariani M, Bombardieri E, Vavassori V, Salmoiraghi P. Pilot scale validation campaign of gel dosimetry for pre-treatment quality assurance in stereotactic radiotherapy. Phys Med 2023; 114:103158. [PMID: 37806152 DOI: 10.1016/j.ejmp.2023.103158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/10/2023] Open
Abstract
PURPOSE Complex stereotactic radiotherapy treatment plans require prior verification. A gel dosimetry system was developed and tested to serve as a high-resolution 3D dosimeter for Quality Assurance (QA) purposes. MATERIALS AND METHODS A modified version of a polyacrylamide polymer gel dosimeter based on chemical response inhibition was employed. Different sample geometries (cuvettes and phantoms) were manufactured for calibration and QA acquisitions. Irradiations were performed with a Varian Trilogy linac, and analyses of irradiated gel dosimeters were performed via MRI with a 1.5 T Philips Achieva at 1 mm3 or 2 mm3 isotropic spatial resolution. To assess reliability of polymer gel data, 54 stereotactic clinical treatment plans were delivered both on dosimetric gel phantoms and on the Delta4 dosimeter. Results from the two devices were evaluated through a global gamma index over a range of acceptance criteria and compared with each other. RESULTS A quantitative and tunable control of dosimetric gel response sensitivity was achieved through chemical inhibition. An optimized MRI analysis protocol allowed to acquire high resolution phantom dose data in timeframes of ≈ 1 h. Conversion of gel dosimeter data into absorbed dose was achieved through internal calibration. Polymer gel dosimeters (2 mm3 resolution) and Delta4 presented an agreement within 4.8 % and 2.7 % at the 3 %/1 mm and 2 %/2 mm gamma criteria, respectively. CONCLUSIONS Gel dosimeters appear as promising tools for high resolution 3D QA. Added complexity of the gel dosimetry protocol may be justifiable in case of small target volumes and steep dose gradients.
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Affiliation(s)
- G Magugliani
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy.
| | - M Marranconi
- U. O. Medical Physics, Humanitas Gavazzeni, Bergamo, Italy
| | - G M Liosi
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - F Locatelli
- U. O. Medical Physics, Humanitas Gavazzeni, Bergamo, Italy
| | - A Gambirasio
- U. O. Medical Physics, Humanitas Gavazzeni, Bergamo, Italy
| | - L Trombetta
- U. O. Medical Physics, Humanitas Gavazzeni, Bergamo, Italy
| | - V Hertsyk
- Fondazione Humanitas per la Ricerca, Milano, Italy
| | - V Torri
- Department of Oncologic Research, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - F Galluccio
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - E Macerata
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - E Mossini
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - A Santi
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - M Mariani
- Department of Energy, Nuclear Engineering Division, Politecnico di Milano, Milano, Italy
| | - E Bombardieri
- Scientific Direction, Humanitas Gavazzeni, Bergamo, Italy
| | - V Vavassori
- U. O. Radiotherapy, Humanitas Gavazzeni, Bergamo, Italy
| | - P Salmoiraghi
- U. O. Medical Physics, Humanitas Gavazzeni, Bergamo, Italy
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18
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Goosheh A, Abtahi SMM, Mahdavi SR. Response investigation of a new polymer gel dosimeter based on ammonium salt through MRI technique. Appl Radiat Isot 2023; 200:110956. [PMID: 37531731 DOI: 10.1016/j.apradiso.2023.110956] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/28/2023] [Accepted: 07/20/2023] [Indexed: 08/04/2023]
Abstract
Increasing the use of polymer gel dosimetry (PGD) in radiotherapy requires reducing its toxicity. The toxicity of the PGD components causes risks for the users as well as the environment. The aim of this study is to produce a new PGD called PAGBIT (Polymer, Amps ammonium salt, Gelatin, BIs, Thpc) based on the nontoxic monomer of 2-acrylamido-2-methylpropanesulfonic acid ammonium salt. Furthermore, this monomer is ecofriendly. The PAGBIT PGD was prepared in the laboratory in ambient conditions. PGDs were irradiated using a clinical accelerator with a dose range of 0-10 Gy. The incident photon energy and dose rate were 6-MV and 300 cGy/min, respectively. The irradiated PGDs were imaged using a 1.5T MRI scanner 9 times in a time range of 12-720 h post-irradiation. The maximum obtained sensitivity was 0.115 ± 0.005 Gy-1s-1 at 36 h post-irradiation time. The average sensitivity change as a function of post-irradiation time was 0.0017 Gy-1s-1h-1. However, the average sensitivity change as a function of scanning temperature was 0.0006 Gy-1s-1°C-1. Results showed that the differences of effective atomic number and electron density between PAGBIT and soft tissue were 2.3% and 0.3%, respectively. It was concluded that the PAGBIT is a low toxic, water equivalent PGD with noticeable temporal and temperature stabilities.
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Affiliation(s)
| | | | - Seied Rabi Mahdavi
- Department of Medical Physics, School of Medicine, Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
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19
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Yao CH, Huang EY, Juan KJ, Juang PJ, Juan YH, Chang YJ. Feasibility evaluation of N-Isopropyl Acrylamide 3D gel dosimeters for proton therapy. PLoS One 2023; 18:e0291507. [PMID: 37699042 PMCID: PMC10497135 DOI: 10.1371/journal.pone.0291507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023] Open
Abstract
This study aimed to investigate the feasibility of applying 3D gel dosimeters for proton therapy. Two different formulations (5-5-3-5, 5-3-3-10) for the N-Isopropyl Acrylamide (NIPAM) polymer gel were used to find the best composition for the application of NIPAM polymer gels for proton therapy. The reaction of the gel under different physical conditions, including dependence on energy and dependence on the dose rate of the NIPAM gel under proton irradiation, was also explored. A NIPAM gel dosimeter was used to record the 3D dose distribution, and a self-developed parallel beam optical computed tomography scanner was used to obtain non-irradiated and post-irradiated gel phantom images. The NIPAM gel was filled into a cylindrical acrylic phantom. The results showed that the optical density of the irradiated NIPAM dosimeter was linear in the dose range of 0 to 6 Gy, and the linearity of the two NIPAM gel formulations at the depth of the dose point (2 cm) was 0.98 to 0.89. The dose depth curves showed different patterns with different gel sensitivities. This study demonstrated that the NIPAM gel dosimeter with the 5-3-3-10 formulation is suitable for verifying the dosimetry dose of proton beams.
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Affiliation(s)
- Chun-Hsu Yao
- Department of Master Program for Biomedical Engineering / School of Chinese Medicine, China Medical University, Taichung City, Taiwan, R.O.C
- Biomaterials Translational Research Center, China Medical University Hospital, Taichung City, Taiwan, R.O.C
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan, R.O.C
- School of Chinese Medicine, China Medical University, Taichung City, Taiwan, R.O.C
- Department of Biomedical Informatics, Asia University, Taichung City, Taiwan, R.O.C
| | - Eng-Yen Huang
- Department of Radiation Oncology, Chang Gung Memorial Hospital Kaohsiung Branch, Niao-Sung District, Kaohsiung, Taiwan, R.O.C
| | - Kuo-Jung Juan
- Department of Radiation Oncology, Chang Gung Memorial Hospital Kaohsiung Branch, Niao-Sung District, Kaohsiung, Taiwan, R.O.C
| | - Pei-Jiuan Juang
- Department of Radiation Oncology, Chang Gung Memorial Hospital Kaohsiung Branch, Niao-Sung District, Kaohsiung, Taiwan, R.O.C
| | - Ying-Hsuan Juan
- Department of Master Program for Biomedical Engineering / School of Chinese Medicine, China Medical University, Taichung City, Taiwan, R.O.C
| | - Yuan-Jen Chang
- Department of Aerospace and Systems Engineering, Feng-Chia University, Taichung, Taiwan, R.O.C
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20
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Qin D, Han Y, Hu L. Enhanced X-ray Dose Response of Radio-fluorescent Hydrogels Enabled by Persulfate Salts. J Fluoresc 2023; 33:2015-2021. [PMID: 36964847 PMCID: PMC10039678 DOI: 10.1007/s10895-023-03205-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/08/2023] [Indexed: 03/26/2023]
Abstract
Coumarin 3-carboxylic acid (CCA)-loaded radio-fluorescent hydrogels have attracted interest for ionizing radiation dosimeters, but their sensitivity needs to be improved. In this study, we added ammonium persulfate (APS) to a polyacrylamide (PAAm)-CCA hydrogel. The introduction of APS improved the hydrogel dose sensitivity to 336.02 Gy- 1, which is 1.8 times that of the counterpart without APS. Our hydrogel can measure the X-ray dose in a range of 0 - 15 Gy with a lower limit of detection (LOD) of 0.1 Gy. Additionally, the hydrogel can sense X-ray doses within a wide range of the dose rate and temperature, and the dose‒response can be well retained 7 days postirradiation. Therefore, we think this study provides a simple and robust method to improve the sensitivity of CCA hydrogel dosimeters, presenting great potential in clinical radiotherapy.
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Affiliation(s)
- Danni Qin
- State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, School for Radiological and Interdisciplinary Sciences (RAD-X), Suzhou Medical College of Soochow University, Soochow University, Suzhou, China
| | - Yaqi Han
- State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, School for Radiological and Interdisciplinary Sciences (RAD-X), Suzhou Medical College of Soochow University, Soochow University, Suzhou, China
| | - Liang Hu
- State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, School for Radiological and Interdisciplinary Sciences (RAD-X), Suzhou Medical College of Soochow University, Soochow University, Suzhou, China.
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21
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Ogilvy A, Collins S, Hilts M, Hare W, Jirasek A. Commissioning of a solid tank design for fan-beam optical CT based 3D radiation dosimetry. Phys Med Biol 2023; 68:175034. [PMID: 37451252 DOI: 10.1088/1361-6560/ace7aa] [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: 02/13/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Objective.Optical computed tomography (CT) is one of the leading modalities for imaging gel dosimeters used in the verification of complex radiotherapy treatments. In previous work, a novel fan-beam optical CT scanner design was proposed that could significantly reduce the volume of the refractive index baths that are commonly found in optical CT systems. Here, the proposed scanner has been manufactured and commissioned.Approach.Image reconstruction is performed through algebraic reconstruction technique and iterated using the fast iterative shrinkage-thresholding algorithm (FISTA) algorithm. Ray tracing for algebraic reconstruction was performed using an in-house developed ray tracing simulator. A set of Sylgard® 184 phantoms were created to commission spatial resolution, geometric deformity, contrast-to-noise ratio (CNR), and scan settings.Main Results.The scanner is capable of a 0.929 mm-1spatial resolution, observed at 200 iterations, although the spatial resolution is highly dependent on the number of iterations. The geometric distortion, measured by scanning a needle phantom with the prototype scanner as well as a conventional x-ray CT was found to be within <0.25 mm. The CNR was found to peak between 65 and 190 occurring between 50 and 100 iterations and was highly dependent on the region chosen for background noise calculation. The proposed scanner is capable of scanning and reading out slices in less than 1 min per slice.Significance.This work displays the viability of a fan-beam optical CT scanner with minimal index matching using ray-traced algebraic reconstruction.
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Affiliation(s)
- A Ogilvy
- Department of Physics, University of British Columbia-Okanagan campus, Kelowna BC V1V 1V7, Canada
| | - S Collins
- Department of Physics, University of British Columbia-Okanagan campus, Kelowna BC V1V 1V7, Canada
| | - M Hilts
- Department of Physics, University of British Columbia-Okanagan campus, Kelowna BC V1V 1V7, Canada
- Medical Physics, BC Cancer-Kelowna, Kelowna BC V1Y 5L3, Canada
| | - W Hare
- Department of Mathematics, University of British Columbia-Okanagan campus, Kelowna BC V1V 1V7, Canada
| | - A Jirasek
- Department of Physics, University of British Columbia-Okanagan campus, Kelowna BC V1V 1V7, Canada
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22
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Zhang T, Almajidi YQ, Awad SA, Alhachami FR, Gatea MA, Kadhum WR. Dosimetric properties of PASSAG polymer gel dosimeter in electron beam radiotherapy using magnetic resonance imaging. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2023:XST230073. [PMID: 37212060 DOI: 10.3233/xst-230073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND Several physical factors such as photon beam energy, electron beam energy, and dose rate may affect the dosimetric properties of polymer gel dosimeters. The photon beam energy and dose rate dependence of PASSAG gel dosimeter were previously evaluated. OBJECTIVE This study aims to assess the dosimetric properties of the optimized PASSAG gel samples in various electron beam energies. METHODS The optimized PASSAG gel samples are first fabricated and irradiated to various electron energies (5, 7, 10 and 12 MeV). Then, the response (R2) and sensitivity of gel samples are analyzed by magnetic resonance imaging technique at a dose range of 0 to 10 Gy, scanning room temperature range of 15 to 22 °C, and post-irradiation time range of 1 to 30 days. RESULTS The R2-dose response and sensitivity of gel samples do not change under the evaluated electron beam energies (the differences are less than 5%). Furthermore, a dose resolution range of 11 to 38 cGy is obtained for the gel samples irradiated to different electron beam energies. Moreover, the findings show that the R2-dose response and sensitivity dependence of gel samples on electron beam energy varies over different scanning room temperatures and post-irradiation times. CONCLUSION The dosimetric assessment of the optimized PASSAG gel samples provides the promising data for this dosimeter during electron beam radiotherapy.
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Affiliation(s)
- Tiancheng Zhang
- Department of Radiology, The First People's Hospital of Lianyungang, Lianyungang, China
| | | | - Sameer A Awad
- Department of Medical Laboratory Techniques, Al-Maarif University College, Al-Anbar-Ramadi, Iraq
| | - Firas Rahi Alhachami
- Radiology Department, College of Health and Medical Technology, Al-Ayen University, Thi-Qar, Iraq
| | - Maher Abdulfadhil Gatea
- Technical Engineering Department College of Technical Engineering, The Islamic University, Najaf, Iraq
| | - Wesam R Kadhum
- Department of Pharmacy, Kut University College, Kut, Wasit, Iraq
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23
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Penev KI, Mulligan M, Mequanint K. Optimization of the Dose Rate Effect in Tetrazolium Gellan Gel Dosimeters. Gels 2023; 9:gels9040334. [PMID: 37102946 PMCID: PMC10137491 DOI: 10.3390/gels9040334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/28/2023] Open
Abstract
Tetrazolium salts provide an appealing candidate for 3D gel dosimeters as they exhibit a low intrinsic color, no signal diffusion and excellent chemical stability. However, a previously developed commercial product (the ClearView 3D Dosimeter) based on a tetrazolium salt dispersed within a gellan gum matrix presented a noticeable dose rate effect. The goal of this study was to find out whether ClearView could be reformulated in order to minimize the dose rate effect by optimizing of the tetrazolium salt and gellan gum concentrations and by the addition a thickening agent, ionic crosslinkers, and radical scavengers. To that goal, a multifactorial design of experiments (DOE) was conducted in small-volume samples (4-mL cuvettes). It showed that the dose rate could be effectively minimized without sacrificing the integrity, chemical stability, or dose sensitivity of the dosimeter. The results from the DOE were used to prepare candidate formulations for larger-scale testing in 1-L samples to allow for fine-tuning the dosimeter formulation and conducting more detailed studies. Finally, an optimized formulation was scaled-up to a clinically relevant volume of 2.7 L and tested against a simulated arc treatment delivery with three spherical targets (diameter 3.0 cm), requiring different doses and dose rates. The results showed excellent geometric and dosimetric registration, with a gamma passing rate (at 10% minimum dose threshold) of 99.3% for dose difference and distance to agreement criteria of 3%/2 mm, compared to 95.7% in the previous formulation. This difference may be of clinical importance, as the new formulation may allow the quality assurance of complex treatment plans, relying on a variety of doses and dose rates; thus, expanding the potential practical application of the dosimeter.
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Affiliation(s)
- Kalin I Penev
- Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, ON N6A 5B9, Canada
- Modus Medical Devices Inc., London, ON N6H 5L6, Canada
| | - Matt Mulligan
- London Regional Cancer Program, London, ON N6A 5W9, Canada
| | - Kibret Mequanint
- Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, ON N6A 5B9, Canada
- Biomedical Engineering Graduate Program, The University of Western Ontario, London, ON N6A 5B9, Canada
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24
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Gallo S, Locarno S. Gel Dosimetry. Gels 2023; 9:gels9040311. [PMID: 37102923 PMCID: PMC10138228 DOI: 10.3390/gels9040311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/28/2023] Open
Abstract
The purpose of radiation therapy (RT) is to cover tumor tissue homogeneously with a planned dose while minimizing the dose to the surrounding healthy tissue [...].
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Affiliation(s)
- Salvatore Gallo
- Dipartimento di Fisica "Aldo Pontremoli", Università di Milano, 20133 Milano, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Milano, 20133 Milano, Italy
| | - Silvia Locarno
- Dipartimento di Fisica "Aldo Pontremoli", Università di Milano, 20133 Milano, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Milano, 20133 Milano, Italy
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25
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Kumahara N, Takemura A, Ishihara S, Noto K, Kojima H, Isomura N, Yokoyama H, Goto I. Sensitivity of a bone-equivalent polymer gel dosimeter for measuring the dose to bone during radiation therapy. Radiol Phys Technol 2023; 16:227-234. [PMID: 36947352 DOI: 10.1007/s12194-023-00710-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/23/2023]
Abstract
Treatment planning systems that use the Monte Carlo algorithm can calculate the dose to the medium (Dm) in non-water-equivalent tissues such as bones. However, Dm cannot be verified using actual measurements; therefore, it is necessary to develop tissue-equivalent dosimeters. In this study, we developed a bone-equivalent polymer gel dosimeter (BPGD) that can measure the dose absorbed by the bone and investigated its sensitivity. The BPGDs were prepared by adding 3.0 mol of calcium hydrogen phosphate dihydrate as a component of bone to an improved dose-sensitive polyacrylamide gelatin and tetrakis hydroxymethyl phosphonium chloride (iPAGAT). One day after preparation, the BPGDs were irradiated with a field size of 15 × 15 cm2 using a 10 MV X-ray beam to evaluate the dose sensitivity, dose-rate dependence, and dose-integration dependence. One day after dose exposure, the BPGDs were scanned using a 0.4 T MRI APERTO Eterna (Hitachi, Tokyo, Japan) to obtain R2 values. The difference between the R2 values of 6 Gy and 0 Gy was up to 5 s-1, and the R2 curve plateaued in the high-dose region. Moreover, the BPGD did not depend on the integration of the dose and dose rates. Therefore, the BPGDs that we developed can determine the radiation dose to bones.
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Affiliation(s)
- Narumi Kumahara
- Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan.
| | - Akihiro Takemura
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Shouta Ishihara
- Department of Clinical Examination, Ogaki Municipal Hospital, Ogaki, Japan
| | - Kimiya Noto
- Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan
| | - Hironori Kojima
- Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan
| | - Naoki Isomura
- Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan
| | - Haruna Yokoyama
- Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan
| | - Itsuki Goto
- Divisions of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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26
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Zhu L, Du Y, Peng Y, Xiang X, Wang X. End-to-End QA with Polymer Gel Dosimeter for Photon Beam Radiation Therapy. Gels 2023; 9:gels9030212. [PMID: 36975661 PMCID: PMC10048457 DOI: 10.3390/gels9030212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/14/2023] Open
Abstract
With the complexity and high demands on quality assurance (QA) of photon beam radiation therapy, end-to-end (E2E) QA is necessary to validate the entire treatment workflow from pre-treatment imaging to beam delivery. A polymer gel dosimeter is a promising tool for three-dimensional (3D) dose distribution measurement. The purpose of this study is to design a fast “one delivery” polymethyl methacrylate (PMMA) phantom with a polymer gel dosimeter for the E2E QA test of the photon beam. The one delivery phantom is composed of ten calibration cuvettes for the calibration curve measurement, two 10 cm gel dosimeter inserts for the dose distribution measurement, and three 5.5 cm gel dosimeters for the square field measurement. The one delivery phantom holder is comparable in size and shape to that of a human thorax and abdomen. In addition, an anthropomorphic head phantom was employed to measure the patient-specific dose distribution of a VMAT plan. The E2E dosimetry was verified by undertaking the whole RT procedure (immobilization, CT simulation, treatment planning, phantom set-up, imaged-guided registration, and beam delivery). The calibration curve, field size, and patient-specific dose were measured with a polymer gel dosimeter. The positioning error can be mitigated with the one-delivery PMMA phantom holder. The delivered dose measured with a polymer gel dosimeter was compared with the planned dose. The gamma passing rate is 86.64% with the MAGAT-f gel dosimeter. The results ascertain the feasibility of the one delivery phantom with a polymer gel dosimeter for a photon beam in E2E QA. The QA time can be reduced with the designed one delivery phantom.
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Affiliation(s)
- Libing Zhu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Yi Du
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Yahui Peng
- School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Xincheng Xiang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Xiangang Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
- Correspondence:
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27
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Abtahi SMM, Bahrami F, Sardari D. An investigation into the dose rate and photon energy dependence of the GENA gel dosimeter in the MeV range. Phys Med 2023; 106:102522. [PMID: 36603480 DOI: 10.1016/j.ejmp.2022.102522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/05/2023] Open
Abstract
PURPOSE In the current study, the energy and dose rate dependence of a new genipin-based gel dosimeter, named GENA gel dosimeter, were investigated. METHODS Prepared gel dosimeters exposed using a Varian clinical linac. Beam qualities of 6 and 18 MV were applied to investigate the GENA gel dosimeter's energy dependence. Furthermore, the gel dosimeters were exposed to 50, 100, 200, and 350 cGy/min dose rates, ranging from 0 to 8 Gy. The irradiated gel dosimeters were read out using a double beam UV-Visible spectrophotometer. The absorbance peak (AP) and area under spectrum (AUS) were evaluated. RESULTS Absorbance-dose sensitivities of (8.0 ± 0.18) × 10-3 cm-1Gy-1 and (7.8 ± 0.15) × 10-3 cm-1Gy-1 were obtained for GENA gel dosimeter for 6 and 18 MV beam qualities, respectively. Results specified no significant difference (p > 0.05) between the GENA gel dosimeter's sensitivities irradiated using the two energies mentioned above. For the mentioned dose rates, AP-dose sensitivities of (8.2 ± 0.22) × 10-3, (8.1 ± 0.21) × 10-3, (8.1 ± 0.2) × 10-3 and (8.0 ± 0.18) × 10-3 cm-1Gy-1 were obtained, respectively. Results showed no significant difference (p > 0.05) between the GENA gel dosimeter's sensitivities for the investigated dose rates and energies. In addition, results revealed that when the incident photon energy and dose rate changed, there were no significant differences (p > 0.05) between the GENA gel dosimeter's dose resolution values. CONCLUSIONS It is concluded that the response of the GENA gel dosimeter is not dependent on the energy and dose rate (p > 0.05) within the studied energy and dose rate ranges.
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Affiliation(s)
| | - Farbod Bahrami
- Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
| | - Dariush Sardari
- Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
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28
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Small field output factor measurement and verification for CyberKnife robotic radiotherapy and radiosurgery system using 3D polymer gel, ionization chamber, diode, diamond and scintillator detectors, Gafchromic film and Monte Carlo simulation. Appl Radiat Isot 2023; 192:110576. [PMID: 36473319 DOI: 10.1016/j.apradiso.2022.110576] [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: 08/22/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022]
Abstract
The dosimetry of small fields has become tremendously important with the advent of intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery, where small field segments or very small fields are used to treat tumors. With high dose gradients in the stereotactic radiosurgery or radiotherapy treatment, small field dosimetry becomes challenging due to the lack of lateral electronic equilibrium in the field, x-ray source occlusion, and detector volume averaging. Small volume and tissue-equivalent detectors are recommended to overcome the challenges. With the lack of a perfect radiation detector, studies on available detectors are ongoing with reasonable disagreement and uncertainties. The joint IAEA and AAPM international code of practice (CoP) for small field dosimetry, TRS 483 (Alfonso et al., 2017) provides guidelines and recommendations for the dosimetry of small static fields in external beam radiotherapy. The CoP provides a methodology for field output factor (FOF) measurements and use of field output correction factors for a series of small field detectors and strongly recommends additional measurements, data collection and verification for CyberKnife (CK) robotic stereotactic radiotherapy/radiosurgery system using the listed detectors and more new detectors so that the FOFs can be implemented clinically. The present investigation is focused on using 3D gel along with some other commercially available detectors for the measurement and verification of field output factors (FOFs) for the small fields available in the CK system. The FOF verification was performed through a comparison with published data and Monte Carlo simulation. The results of this study have proved the suitability of an in-house developed 3D polymer gel dosimeter, several commercially available detectors, and Gafchromic films as a part of small field dosimetric measurements for the CK system.
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29
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Nemoto M. [[Radiation Therapy] 3. Fabrication and Evaluation of Gel Dosimeters as 3D-Dose Distribution Phantom]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023; 79:65-70. [PMID: 36682780 DOI: 10.6009/jjrt.2023-2139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Mikio Nemoto
- Department of Radiotherapy, Jichi Medical University hospital
- Emergent Bioinspired Soft Matter Research Team, Center for Emergent Matter Science, RIKEN
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30
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Průšová H, Dudáš D, Spěváček V, Průša P. Dose-response dependencies of Turnbull blue, modified Fricke, VIPET, and Presage® gel dosimeters in high-dose-rate radiation fields. RADIAT MEAS 2023. [DOI: 10.1016/j.radmeas.2023.106910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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31
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El-Kelany MA, Khozemy EE, Goda H, Boshra Awad. Preparation of polymer gel dosimeters for low gamma irradiation dose. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2022-0106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
In this study, two separate hydrogel dosimeters were prepared for low-dose measurement. The first system is based on Congo Red (CR) dye and a blend of natural polymers (gelatin/CMC) while the second system is based on 2,6-dichlorophenol indophenol (DCP) blue dye and a hybrid polymer blend (PVA/gelatin/CMC). The sensitivity of Congo red (CR)–(gelatin/CMC) gel dosimeter and 2, 6 – di choro phenol indophenols(DCP)-(PVA/gelatin/CMC) gel dosimetry systems were examined by studying the comparative results between the two different systems through the change in optical properties upon exposure to different gamma radiation doses, which showed the sensitivity of the second system (DCP)-(PVA/gelatin/CMC) to radiation is more than the first system(CR)–(gelatin/CMC) (CR) and (DCP)dyes have absorbance crest at 492 and 622 nm respectively. With the increase of the radiation dose, the decomposition of the dyes increases, and thus the color of the prepared hydrogel changes from orange to colorless in the case of (CR) dye at the dose (0–3.5 kGy) and from blue to colorless in the case (DCP) dye at the absorbed doses ranged from (0–1000 Gy). Dose-response curves, sensitivity, FTIR analysis, and the relative stability of the prepared hydrogel before and after irradiation were studied.
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Affiliation(s)
- Moushera A. El-Kelany
- Radiation Protection and Dosimetry Department , National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority , Cairo , Egypt
| | - Ehab E. Khozemy
- Polymer Chemistry Department , National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority , Cairo , Egypt
| | - Heba Goda
- Chemistry Department, Faculty of Women for Arts, Science and Education , Ain Shams University , Cairo , Egypt
| | - Boshra Awad
- Chemistry Department, Faculty of Women for Arts, Science and Education , Ain Shams University , Cairo , Egypt
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32
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Watanabe Y, Maeyama T, Mizukami S, Tachibana H, Terazaki T, Takei H, Muraishi H, Gomi T, Hayashi SI. Verification of dose distribution in high dose-rate brachytherapy for cervical cancer using a normoxic N-vinylpyrrolidone polymer gel dosimeter. JOURNAL OF RADIATION RESEARCH 2022; 63:838-848. [PMID: 36109319 PMCID: PMC9726700 DOI: 10.1093/jrr/rrac053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/14/2022] [Indexed: 05/10/2023]
Abstract
The polymer gel dosimeter has been proposed for use as a 3D dosimeter for complex dose distribution measurement of high dose-rate (HDR) brachytherapy. However, various shapes of catheter/applicator for sealed radioactive source transport used in clinical cases must be placed in the gel sample. The absorbed dose readout for the magnetic resonance (MR)-based polymer gel dosimeters requires calibration data for the dose-transverse relaxation rate (R2) response. In this study, we evaluated in detail the dose uncertainty and dose resolution of three calibration methods, the multi-sample and distance methods using the Ir-192 source and the linear accelerator (linac) method using 6MV X-rays. The use of Ir-192 sources increases dose uncertainty with steep dose gradients. We clarified that the uniformly irradiated gel sample improved the signal-to-noise ratio (SNR) due to the large slice thickness of MR images and could acquire an accurate calibration curve using the linac method. The curved tandem and ovoid applicator used for intracavitary irradiation of HDR brachytherapy for cervical cancer were reproduced with a glass tube to verify the dose distribution. The results of comparison with the treatment planning system (TPS) calculation by gamma analysis on the 3%/2 mm criterion were in good agreement with a gamma pass rate of 90%. In addition, the prescription dose could be evaluated accurately. We conclude that it is easy to place catheter/applicator in the polymer gel dosimeters, making them a useful tool for verifying the 3D dose distribution of HDR brachytherapy with accurate calibration methods.
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Affiliation(s)
- Yusuke Watanabe
- Corresponding author. School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan. E-mail:
| | - Takuya Maeyama
- School of Science, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shinya Mizukami
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hidenobu Tachibana
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan
| | - Tsuyoshi Terazaki
- Department of Radiology, Yokohama City Minato Red Cross Hospital, 3-12-1 Shinyamashita, Naka-ku, Yokohama, Kanagawa, 231-8682, Japan
| | - Hideyuki Takei
- Quantum Life and Medical Science Directorate, National Institute for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
| | - Hiroshi Muraishi
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Tsutomu Gomi
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shin-ichiro Hayashi
- Faculty of Health Sciences, Hiroshima International University, 555-36 Kurosegakuendai, Higashihiroshima, Hiroshima, 739-2695, Japan
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33
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Kozicki M, Maras P. Features of 2Day.QA® as a 2D radiation dosimeter. Phys Med 2022; 104:23-31. [PMID: 36356501 DOI: 10.1016/j.ejmp.2022.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/21/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE A new commercial 2D ionising radiation dosimeter (2Day.QA®) was developed. This work aims to introduce the basic functions of 2Day.QA®. METHODS The dosimeter is made mainly of a linear polysaccharide consisting of β(1 → 4) linked d-glucose units and radiation active substances, which make it environmentally friendly. For 2Day.QA® irradiation, radiotherapy ionising radiation sources were used. The analysis of 2Day.QA® was performed using three scanners: Vidar® Red LED Dosimetry Pro Advantage™, Vidar® VXR 12-plus™ and HP Scanjet G3010 flatbed scanner. The stability of 2Day.QA® was tested. Exemplary applications of 2DayQA® for QA studies of accelerator light and radiation field coincidence and brachytherapy source position were carried out. RESULTS The dosimeter responded to the lowest applied dose of 0.95 Gy and saturated at over 94.9 Gy. The quasi-linear dose response is below 20 Gy. Vidar® Red LED Dosimetry Pro Advantage™ has proven to be superior to other scanners at determining dose effects in 2Day.QA®. The stability of the non-irradiated 2Day.QA® is at least 18 months. After 18 months of storage, the dosimeter reacted to irradiation. In the case of the irradiated samples, a slight color drift related to the absorbed dose was observed. Tests of the use of 2Day.QA® to control the quality of the accelerator light and radiation field coincidence and brachytherapy source position have shown that it can be used for such applications. CONCLUSIONS The study reveals the potential of 2Day.QA® for 2D radiation dosimetry and concludes with recommendations for the use of the dosimeter for radiotherapy QA tests.
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34
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Wheatley M, De Deene Y. A novel anthropomorphic breathing phantom with a pneumatic MR-safe actuator for tissue deformation studies during MRI and radiotherapy. Phys Med 2022; 104:43-55. [PMID: 36368090 DOI: 10.1016/j.ejmp.2022.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/01/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022] Open
Abstract
A novel MR-safe anthropomorphic torso phantom with an MR-conditional pneumatic respiration system and inflatable lungs for tissue deformation studies is proposed. The phantom consists of a pair of lungs made from sponges encased in flexible polyurethane. The lung phantom also contains a set of silicone tubes of various diameters to mimic the larger vasculature and airways of the lungs. The lungs are surrounded by a plastic ribcage and immersed in a gelatine hydrogel within a flexible polyurethane skin. A plastic pneumatic pump system was constructed to inflate and deflate the lungs. A fibre optic rotary encoder was constructed to determine the volume of displaced air in the lungs. The pneumatic pump and rotary encoder were constructed of plastic materials to allow placement within the bore of the MR scanner with minimal interaction with the magnetic field. Breath-gated scans and rapid imaging scans (2.5 s per image) were taken of the phantom in the stationary state and during inflation/deflation, and with Cartesian and BLADE k-space sampling. It was found that BLADE shows the least motion artifacts during breathing. This phantom and respiration system shows potential for quality assurance of MRI incorporating breathing corrections and for radiotherapy applications in tracking a moving target.
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Affiliation(s)
- Morgan Wheatley
- Faculty of Science and Engineering, Macquarie University, Sydney, Australia.
| | - Yves De Deene
- Faculty of Science and Engineering, Macquarie University, Sydney, Australia; Faculty of Science, Western Sydney University, Sydney, Australia
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35
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Welti SE, Taño JE, Gonzales CAB, Yasuda H. Investigation on the long-term storage condition of the PVA-GTA-I gel dosimeter. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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36
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Chemical Overview of Gel Dosimetry Systems: A Comprehensive Review. Gels 2022; 8:gels8100663. [PMID: 36286165 PMCID: PMC9601373 DOI: 10.3390/gels8100663] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022] Open
Abstract
Advances in radiotherapy technology during the last 25 years have significantly improved both dose conformation to tumors and the preservation of healthy tissues, achieving almost real-time feedback by means of high-precision treatments and theranostics. Owing to this, developing high-performance systems capable of coping with the challenging requirements of modern ionizing radiation is a key issue to overcome the limitations of traditional dosimeters. In this regard, a deep understanding of the physicochemical basis of gel dosimetry, as one of the most promising tools for the evaluation of 3D high-spatial-resolution dose distributions, represents the starting point for developing new and innovative systems. This review aims to contribute thorough descriptions of the chemical processes and interactions that condition gel dosimetry outputs, often phenomenologically addressed, and particularly formulations reported since 2017.
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Krauleidis A, Adliene D, Rutkuniene Z. The Impact of Temporal Changes in Irradiated nMAG Polymer Gels on Their Applicability in Small Field Dosimetry in Radiotherapy. Gels 2022; 8:629. [PMID: 36286130 PMCID: PMC9601347 DOI: 10.3390/gels8100629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/16/2022] Open
Abstract
As advanced radiotherapy techniques progress to deliver a high absorbed dose to the target volume while minimizing the dose to normal tissues using intensity-modulated beams, arcs or stereotactic radiosurgery, new challenges occur to assure that the high treatment dose is delivered homogeneously to the tumor. Small irradiation field sizes (≤1 cm2) that tightly conform to precise target regions and allow for the deliverance of doses with a high therapeutic ratio, are of particular interest. However, the small field dosimetry using conventional dosimeters is limited by the relative large size of the detector. Radiation-sensitive polymer gels have the potential to meet this dosimetry challenge due to their almost unlimited ability in resolving three-dimensional dose distributions of any shape and makes them unique and suitable for the evaluation of dose profiles and the verification of complex doses. In this work, dose distributions in nMAG gels that have been irradiated to different doses by applying a 6 MV FFF photon beam collimated to 1 cm2, were analyzed and the dose profiles were evaluated by applying a gamma passing rate criteria of 3%/3 mm and considering different post-irradiation time intervals between the irradiation and the gels read out process. X-ray CT and NMR imaging procedures were used for the dose evaluation. It was found that the shape and uniformity of the dose profiles were changing due to post-irradiation polymerization and gelation processes, indicating time dependent growing uniformity which was better expressed for the higher delivered doses. It was estimated that in order to obtain acceptably symmetric small field dose profiles, a longer post-irradiation time is needed for getting the full scope of the polymerization as compared with the recently recommended 24 h period between irradiation and the read out processes of the dose gels. An estimated overall uncertainty (double standard deviation, 95% confidence level) of 3.66% was achieved by applying R2 measurements (NMR read out), and a 3.81-applying X-ray CT read out for 12 Gy irradiated gels 56 h post-irradiation. An increasing tendency for the uncertainty was observed with a decreasing post-irradiation time. A gamma passing rate of 90.3% was estimated for the 12 Gy irradiated gels and, 56 h post-irradiation, the X-ray CT evaluated gels as well as a gamma passing rate of 92.7% was obtained for the NMR evaluated gels applying a 3%/3 mm passing criteria.
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Affiliation(s)
| | - Diana Adliene
- Physics Department, Kaunas University of Technology, Studentu Str. 50, 51368 Kaunas, Lithuania
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Rabaeh KA, Al-Zawaydaih HH, Eyadeh MM, Shatnawi MT. High optical stability of reusable radiochromic polyvinyl alcohol-iodine gel dosimeter for radiotherapy. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Javaheri N, Yarahmadi M, Refaei A, Aghamohammadi A. Investigating the Sensitivity of New Formulation MAGAT and NIPAM Polymer Gels in the Radiation Therapy Dosimetry. J Biomed Phys Eng 2022; 12:489-496. [PMID: 36313403 PMCID: PMC9589084 DOI: 10.31661/jbpe.v0i0.1912-1008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/06/2020] [Indexed: 06/16/2023]
Abstract
BACKGROUND Normoxic polymer gels have been used as a three dimensional (3D) dosimeter in radiation therapy, recently. The sensitivity of these gels is important in dosimetry and their improvement can be also useful. OBJECTIVE In this study, different modalities of gel reading were used and the structure of gel changed due to the best improvement of sensitivity. The sensitivities of the new formulation of Methacrylic acid gel (MAGAT) and N-isopropyl acrylamide (NIPAM) polymer gel dosimeters were studied using two different reading methods of magnetic resonance imaging (MRI) and X-ray computed tomography (X-ray CT). MATERIAL AND METHODS In this experimental study, in addition to making the NIPAM polymer gel dosimeter, a new formulation of normoxic polymer gel dosimeter, which named MAGAT gel, was investigated. The gels were irradiated with 6 MV in low doses, including1, 1.5, 1.75, 2 and 2.5 Gy. MRI and X-ray CT did the reading of gel dosimeters a day after irradiation using an elevated protocol. RESULTS The dose sensitivities of 0.92 HGy-1 and 0.47 HGy-1 were obtained for new MAGAT and NIPAM polymer gel dosimeters, respectively, based on the X-ray CT reading modality. The use of MRI reading modality and the dose sensitivities were 0.74 S-1Gy-1 and 0.27 S-1Gy-1 for new MAGAT and NIPAM polymer gel dosimeters, respectively. CONCLUSION The new formulation of MAGAT polymer gel with a suitable protocol of gel reading has a better response.
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Affiliation(s)
- Negin Javaheri
- PhD Candidate, Department of Physics, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
| | - Mehran Yarahmadi
- PhD, Department of Medical Physics, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Abdollah Refaei
- PhD, Department of Physics, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
| | - Ali Aghamohammadi
- PhD, Department of Physics, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
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Maras P, Kozicki M. Fast Isocenter Determination Using 3D Polymer Gel Dosimetry with Kilovoltage Cone-Beam CT Reading and the PolyGeVero-CT Software Package for Linac Quality Assurance in Radiotherapy. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6807. [PMID: 36234149 PMCID: PMC9573670 DOI: 10.3390/ma15196807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/23/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
This work presents an approach to the fast determination of a medical accelerator irradiation isocenter as a quality assurance (QA) procedure in radiotherapy. The isocenter determination tool is the tissue equivalent high-resolution 3D polymer gel dosimeter (PABIGnx) in a dedicated container combined with kilovoltage imaging systems and the polyGeVero-CT software package (v. 1.2, GeVero Co., Poland). Two accelerators were employed: Halcyon and TrueBeam (Varian, USA), both equipped with cone beam computed tomography (CBCT) and iterative reconstruction CBCT (iCBCT) algorithms. The scope of this work includes: (i) the examination of factors influencing image quality (reconstruction algorithms and modes), radiation field parameters (dose and multi-leaf collimator (MLC) gaps), fiducial markers, signal averaging for reconstruction algorithms and the scanning time interval between consecutive scans, (ii) the examination of factors influencing the isocenter determination, image processing (signal averaging, background subtraction, image filtering) and (iii) an isocenter determination report using a 2D and 3D approach. An optimized protocol and isocenter determination conditions were found. The time and effort required to determine the isocenter are discussed.
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Affiliation(s)
- Piotr Maras
- Department of Radiotherapy Planning, Copernicus Hospital, 93-513 Lodz, Poland
- GeVero Co., Tansmana 2/11, 92-548 Lodz, Poland
| | - Marek Kozicki
- GeVero Co., Tansmana 2/11, 92-548 Lodz, Poland
- Department of Mechanical Engineering, Informatics and Chemistry of Polymer Materials, Faculty of Materials Technologies and Textile Design, Lodz University of Technology, 90-543 Lodz, Poland
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De Deene Y. Radiation Dosimetry by Use of Radiosensitive Hydrogels and Polymers: Mechanisms, State-of-the-Art and Perspective from 3D to 4D. Gels 2022; 8:599. [PMID: 36135311 PMCID: PMC9498652 DOI: 10.3390/gels8090599] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/07/2022] [Accepted: 09/10/2022] [Indexed: 12/22/2022] Open
Abstract
Gel dosimetry was developed in the 1990s in response to a growing need for methods to validate the radiation dose distribution delivered to cancer patients receiving high-precision radiotherapy. Three different classes of gel dosimeters were developed and extensively studied. The first class of gel dosimeters is the Fricke gel dosimeters, which consist of a hydrogel with dissolved ferrous ions that oxidize upon exposure to ionizing radiation. The oxidation results in a change in the nuclear magnetic resonance (NMR) relaxation, which makes it possible to read out Fricke gel dosimeters by use of quantitative magnetic resonance imaging (MRI). The radiation-induced oxidation in Fricke gel dosimeters can also be visualized by adding an indicator such as xylenol orange. The second class of gel dosimeters is the radiochromic gel dosimeters, which also exhibit a color change upon irradiation but do not use a metal ion. These radiochromic gel dosimeters do not demonstrate a significant radiation-induced change in NMR properties. The third class is the polymer gel dosimeters, which contain vinyl monomers that polymerize upon irradiation. Polymer gel dosimeters are predominantly read out by quantitative MRI or X-ray CT. The accuracy of the dosimeters depends on both the physico-chemical properties of the gel dosimeters and on the readout technique. Many different gel formulations have been proposed and discussed in the scientific literature in the last three decades, and scanning methods have been optimized to achieve an acceptable accuracy for clinical dosimetry. More recently, with the introduction of the MR-Linac, which combines an MRI-scanner and a clinical linear accelerator in one, it was shown possible to acquire dose maps during radiation, but new challenges arise.
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Affiliation(s)
- Yves De Deene
- Liverpool & Macarthur Cancer Therapy Centres, Liverpool, NSW 1871, Australia; or
- Ingham Institute, Liverpool, NSW 2170, Australia
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
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da Silveira MA, Pavoni JF, Bruno AC, Arruda GV, Baffa O. Three-Dimensional Dosimetry by Optical-CT and Radiochromic Gel Dosimeter of a Multiple Isocenter Craniospinal Radiation Therapy Procedure. Gels 2022; 8:gels8090582. [PMID: 36135294 PMCID: PMC9498794 DOI: 10.3390/gels8090582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
Craniospinal irradiation (CSI) is a complex radiation technique employed to treat patients with primitive neuroectodermal tumors such as medulloblastoma or germinative brain tumors with the risk of leptomeningeal spread. In adults, this technique poses a technically challenging planning process because of the complex shape and length of the target volume. Thus, it requires multiple fields and different isocenters to guarantee the primary-tumor dose delivery. Recently, some authors have proposed the use IMRT technique for this planning with the possibility of overlapping adjacent fields. The high-dose delivery complexity demands three-dimensional dosimetry (3DD) to verify this irradiation procedure and motivated this study. We used an optical CT and a radiochromic Fricke-xylenol-orange gel with the addition of formaldehyde (FXO-f) to evaluate the doses delivered at the field junction region of this treatment. We found 96.91% as the mean passing rate using the gamma analysis with 3%/2 mm criteria at the junction region. However, the concentration of fail points in a determined region called attention to this evaluation, indicating the advantages of employing a 3DD technique in complex dose-distribution verifications.
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Affiliation(s)
| | | | - Alexandre Colello Bruno
- Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto–USP, Ribeirão Preto 14015-010, Brazil
| | - Gustavo Viani Arruda
- Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto–USP, Ribeirão Preto 14015-010, Brazil
| | - Oswaldo Baffa
- Departamento de Física, FFCLRP—Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil
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Farahani S, Mosleh-Shirazi MA, Riyahi Alam N, Rabi Mahdavi S, Raeisi F. Global and spatial dosimetric characteristics of N-vinylpyrrolidone-based polymer gel dosimeters as a function of medium-term post-preparation and post-irradiation time. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nikolić N, Spasojević J, Radosavljević A, Milošević M, Barudžija T, Rakočević L, Kačarević-Popović Z. Influence of poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidone) polymer matrix composition on the bonding environment and characteristics of Ag nanoparticles produced by gamma irradiation. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Nierer L, Kamp F, Reiner M, Corradini S, Rabe M, Dietrich O, Parodi K, Belka C, Kurz C, Landry G. Evaluation of an anthropomorphic ion chamber and 3D gel dosimetry head phantom at a 0.35 T MR-linac using separate 1.5 T MR-scanners for gel readout. Z Med Phys 2022; 32:312-325. [PMID: 35305857 PMCID: PMC9948847 DOI: 10.1016/j.zemedi.2022.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 12/22/2022]
Abstract
PURPOSE To date, no universally accepted technique for the evaluation of the overall dosimetric performance of hybrid integrated magnetic resonance imaging (MR) - linear accelerators (linacs) is available. We report on the suitability and reliability of a novel phantom with modular inserts for combined polymer gel (PG) and ionisation chamber (IC) measurements at a 0.35 T MR-linac. METHODS Three 3D-printed, modular head phantoms, based on real patient anatomy, were used for repeated (2 times) PG irradiations of cranial treatment plans on a 0.35 T MR-linac. The PG readout was performed on two 1.5 T diagnostic MR-scanners to reduce scanning time. The PG dose volumes were normalised to the IC dose (normalised dose N1) and to the median planning target volume dose (normalised dose N2). Linearity of the PG dose response was validated and dose profiles, centres of mass (COM) of the 95% isodoses and dose volume histograms (DVH) were compared between planned and measured dose distributions and a 3D gamma analysis was performed. RESULTS Dose linearity of the PG was good (R2> 0.99 for all linear fit functions). High agreement was found between planned and measured dose volumes in the dose profiles and DVHs. The largest dose deviation was found in the intermediate dose region (mean dose deviation 0.2Gy; 5.6%). A mean COM offset of 1.2mm indicated high spatial accuracy. Mean 3D gamma passing rates (2%, 2mm) of 83.3% for N1 and 91.6% for N2 dose distributions were determined. When comparing repeated PG measurements to each other, a mean gamma passing rate of 95.7% was found. CONCLUSION The new modular phantom was found practical for use at a 0.35 T MR-linac. In contrast to the high dose region, larger mean deviations were found in the mid dose range. The PG measurements showed high reproducibility. The MR-linac performed well in a non-adaptive setting in terms of spatial and dosimetric accuracy.
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Affiliation(s)
- Lukas Nierer
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany.
| | - Florian Kamp
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany; Department of Radiation Oncology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Moritz Rabe
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Olaf Dietrich
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany; German Cancer Consortium (DKTK), partner site Munich, Munich, Germany
| | - Christopher Kurz
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Guillaume Landry
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
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Zirone L, Bonanno E, Borzì GR, Cavalli N, D’Anna A, Galvagno R, Girlando A, Gueli AM, Pace M, Stella G, Marino C. HyperArc TM Dosimetric Validation for Multiple Targets Using Ionization Chamber and RT-100 Polymer Gel. Gels 2022; 8:481. [PMID: 36005082 PMCID: PMC9407338 DOI: 10.3390/gels8080481] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
Multiple brain metastases single-isocenter stereotactic radiosurgery (SRS) treatment is increasingly employed in radiotherapy department. Before its use in clinical routine, it is recommended to perform end-to-end tests. In this work, we report the results of five HyperArcTM treatment plans obtained by both ionization chamber (IC) and polymer gel. The end-to-end tests were performed using a water equivalent Mobius Verification PhantomTM (MVP) and a 3D-printed anthropomorphic head phantom PseudoPatient® (PP) (RTsafe P.C., Athens, Greece); 2D and 3D dose distributions were evaluated on the PP phantom using polymer gel (RTsafe). Gels were read by 1.5T magnetic resonance imaging (MRI). Comparison between calculated and measured distributions was performed using gamma index passing rate evaluation by different criteria (5% 2 mm, 3% 2 mm, 5% 1 mm). Mean point dose differences of 1.01% [min −0.77%−max 2.89%] and 0.23% [min 0.01%−max 2.81%] were found in MVP and PP phantoms, respectively. For each target volume, the obtained results in terms of gamma index passing rate show an agreement >95% with 5% 2 mm and 3% 2 mm criteria for both 2D and 3D distributions. The obtained results confirmed that the use of a single isocenter for multiple lesions reduces the treatment time without compromising accuracy, even in the case of target volumes that are quite distant from the isocenter.
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Affiliation(s)
- Lucia Zirone
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Elisa Bonanno
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Giuseppina Rita Borzì
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Nina Cavalli
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Alessia D’Anna
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Rosaria Galvagno
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Andrea Girlando
- Radiotherapy Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy;
| | - Anna Maria Gueli
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Martina Pace
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Giuseppe Stella
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Carmelo Marino
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
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Mohyedin MZ, Zin HM, Adenan MZ, Abdul Rahman AT. A Review of PRESAGE Radiochromic Polymer and the Compositions for Application in Radiotherapy Dosimetry. Polymers (Basel) 2022; 14:2887. [PMID: 35890665 PMCID: PMC9320230 DOI: 10.3390/polym14142887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/02/2022] [Accepted: 07/06/2022] [Indexed: 02/01/2023] Open
Abstract
Recent advances in radiotherapy technology and techniques have allowed a highly conformal radiation to be delivered to the tumour target inside the body for cancer treatment. A three-dimensional (3D) dosimetry system is required to verify the accuracy of the complex treatment delivery. A 3D dosimeter based on the radiochromic response of a polymer towards ionising radiation has been introduced as the PRESAGE dosimeter. The polyurethane dosimeter matrix is combined with a leuco-dye and a free radical initiator, whose colour changes in proportion to the radiation dose. In the previous decade, PRESAGE gained improvement and enhancement as a 3D dosimeter. Notably, PRESAGE overcomes the limitations of its predecessors, the Fricke gel and the polymer gel dosimeters, which are challenging to fabricate and read out, sensitive to oxygen, and sensitive to diffusion. This article aims to review the characteristics of the radiochromic dosimeter and its clinical applications. The formulation of PRESAGE shows a delicate balance between the number of radical initiators, metal compounds, and catalysts to achieve stability, optimal sensitivity, and water equivalency. The applications of PRESAGE in advanced radiotherapy treatment verifications are also discussed.
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Affiliation(s)
- Muhammad Zamir Mohyedin
- School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia;
- Centre of Astrophysics & Applied Radiation, Institute of Science, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Hafiz Mohd Zin
- Advanced Medical & Dental Institute, Universiti Sains Malaysia, Bertam, Kepala Batas 13700, Penang, Malaysia;
| | - Mohd Zulfadli Adenan
- Centre of Medical Imaging, Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Selangor Campus of Puncak Alam, Puncak Alam 42300, Selangor, Malaysia;
| | - Ahmad Taufek Abdul Rahman
- School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia;
- Centre of Astrophysics & Applied Radiation, Institute of Science, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
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Shih TY, Chen WT, Kuo WC, Wu J. Application of Polarization-sensitive Optical Coherence Tomography in Measurement of Gel Dosimeters. J Med Biol Eng 2022. [DOI: 10.1007/s40846-022-00711-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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49
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Sanei M, Ramzanpour RA, Goodarzi AH, Hasanzadeh H. Introducing a chemical-based gel dosimeter for radiation measurement. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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50
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Lin J, Yin M, Liu X, Meng F, Luo L. Nanomaterials Based on Functional Polymers for Sensitizing Cancer Radiotherapy. Macromol Rapid Commun 2022; 43:e2200194. [PMID: 35578790 DOI: 10.1002/marc.202200194] [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: 02/27/2022] [Revised: 04/21/2022] [Indexed: 11/12/2022]
Abstract
Despite being the mainstay treatment for many types of cancer in clinic, radiotherapy is undertaking great challenges in overcoming a series of limitations. Radiosensitizers are promising agents capable of depositing irradiation energy and generating free radicals to enhance the radiosensitivity of tumor cells. Combining radiosensitizers with functional polymer-based nanomaterials holds great potential to improve biodistribution, circulation time, and stability in vivo. The derived polymeric nano-radiosensitizers can significantly improve the efficiency of tumor targeting and radiotherapy, and reduce the side effect to healthy tissues. In this review, we provide an overview of functional polymer-based nanomaterials for radiosensitization in recent years. Particular emphases are given to the action mechanisms, drug loading methods, targeting efficiencies, the impact on therapeutic effects and biocompatibility of various radiosensitizing polymers, which are classified as polymeric micelles, dendrimers, polymeric nanospheres, nanoscale coordination polymers, polymersomes, and nanogels. The challenges and outlooks of polymeric nano-radiosensitizers are also discussed. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jinfeng Lin
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.,Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Mingming Yin
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.,Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiaoming Liu
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Hubei Province Key Laboratory of Molecular Imaging, Wuhan, 430022, China
| | - Fanling Meng
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.,Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Liang Luo
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.,Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
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