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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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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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Development and Application of MAGIC-f Gel in Cancer Research and Medical Imaging. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11177783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Much of the complex medical physics work requires radiation dose delivery, which requires dosimeters to accurately measure complex three-dimensional dose distribution with good spatial resolution. MAGIC-f polymer gel is one of the emerging new dosimeters widely used in medical physics research. The purpose of this study was to present an overview of polymer gel dosimetry, using MAGIC-f gel, including its composition, manufacture, imaging, calibration, and application to medical physics research. In this review, the history of polymer gel development is presented, along with the applications so far. Moreover, the most important experiments/applications of MAGIC-f polymer gel are discussed to illustrate the behavior of gel on different conditions of irradiation, imaging, and manufacturing techniques. Finally, various future works are suggested based on the past and present works on MAGIC-f gel and polymer gel in general, with the hope that these bits of knowledge can provide important clues for future research on MAGIC-f gel as a dosimeter.
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Kozicki M, Jaszczak M, Maras P, Naglik R, Dudek M, Kadlubowski S, Wach R. Preliminary study on a 3D lung mimicking dosimeter based on Pluronic F-127 matrix. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kozicki M, Bartosiak M, Dudek M, Kadlubowski S. LCV-Pluronic F-127 dosimeter for UV light dose distribution measurements. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112930] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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McDonald BA, Lee HJ, Ibbott GS. Low-density gel dosimeter for measurement of the electron return effect in an MR-linac. Phys Med Biol 2019; 64:205016. [PMID: 31505483 DOI: 10.1088/1361-6560/ab4321] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Radiation therapy in the presence of a strong magnetic field is known to cause regions of enhanced and reduced dose at interfaces of materials with varying densities, in a phenomenon known as the electron return effect (ERE). In this study, a novel low-density gel dosimeter was developed to simulate lung tissue and was used to measure the ERE at the lung-soft tissue interface. Low-density gel dosimeters were developed with Fricke xylenol orange gelatin (FXG) and ferrous oxide xylenol orange (FOX) gels mixed with polystyrene foam beads of various sizes. The gels were characterized based on CT number, MR signal intensity, and uniformity. All low-density gels had CT numbers roughly equivalent to lung tissue. The optimal lung-equivalent gel formulation was determined to be FXG with <1 mm polystyrene beads due to the higher signal intensity of FXG compared to FOX and the higher uniformity with the small beads. Dose response curves were generated for the optimal low-density gel and conventional FXG. The change in spin-lattice relaxation rate (R1) before and after irradiation was linear with dose for both gels. Next, phantoms consisting of concentric cylinders with low-density and conventional FXG were created to simulate the lung-soft tissue interface. The phantoms were irradiated in a conventional linear accelerator (linac) and in a linac combined with a 1.5 T magnetic resonance imaging (MRI) unit (MR-linac) to measure the effects of the magnetic field on the dose distribution. Hot and cold spots were observed in the dose distribution at the boundaries between the gels for the phantom irradiated in the MR-linac but not the conventional linac, consistent with the ERE.
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Affiliation(s)
- Brigid A McDonald
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America. Medical Physics Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States of America. Author to whom correspondence should be addressed
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Rabaeh KA, Basfar AA, Almousa AA, Devic S, Moftah B. New normoxic N-(Hydroxymethyl)acrylamide based polymer gel for 3D dosimetry in radiation therapy. Phys Med 2017; 33:121-126. [PMID: 28094138 DOI: 10.1016/j.ejmp.2016.12.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 12/05/2016] [Accepted: 12/28/2016] [Indexed: 11/15/2022] Open
Abstract
A novel composition of normoxic polymer gel dosimeters based on radiation-induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) is introduced in this study for 3D dosimetry for Quality Assurance (QA) in radiation therapy. Dosimeters were irradiated by 6, 10 and 18MV photon beams of a medical linear accelerator at various dose rates to doses of up to 20Gy. The dose response of polymer gel dosimeters was studied using nuclear magnetic resonance (NMR) spin-spin relaxation rate (R2) of hydrogen protons within the water molecule. Also, we measured gel response using absorption spectroscopy and found that this novel gel can be successfully utilized for both MRI- and OCT- (Optical Computed Tomography) based 3D dosimetry. We investigated dosimetric properties of six different compositions of the new NHMA-based gel in terms of dose rate, radiation beam quality and stability of dose-dependent polymerization after irradiation. We found no significant effects of these parameters on the novel gel dosimeter performance in both relaxation rate and absorbance measurements.
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Affiliation(s)
- Khalid A Rabaeh
- Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia; Medical Imaging Department, Faculty of Allied Health Sciences, Hashemite University, Zarqa, Jordan.
| | - Ahmed A Basfar
- Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Akram A Almousa
- Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, Québec, Canada
| | - Belal Moftah
- Biomedical Physics Department, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Medical Physics Unit, McGill University, Montréal, Québec, Canada
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Shahbazi-Gahrouei D, Gholami M, Pourfallah TA, Keshtkar M. Does nitrogen gas bubbled through a low density polymer gel dosimeter solution affect the polymerization process? Adv Biomed Res 2015; 4:88. [PMID: 26015914 PMCID: PMC4434445 DOI: 10.4103/2277-9175.156651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 05/12/2014] [Indexed: 11/12/2022] Open
Abstract
Background: On account of the lower electron density in the lung tissue, the dose distribution in the lung cannot be verified with the existing polymer gel dosimeters. Thus, the aims of this study are to make a low density polymer gel dosimeter and investigate the effect of nitrogen gas bubbles on the R2 responses and its homogeneity. Materials and Methods: Two different types of low density polymer gel dosimeters were prepared according to a composition proposed by De Deene, with some modifications. In the first type, no nitrogen gas was perfused through the gel solution and water. In the second type, to expel the dissolved oxygen, nitrogen gas was perfused through the water and gel solution. The post-irradiation times in the gels were 24 and 5 hours, respectively, with and without perfusion of nitrogen gas through the water and gel solution. Results: In the first type of gel, there was a linear correlation between the doses and R2 responses from 0 to 12 Gy. The fabricated gel had a higher dynamic range than the other low density polymer gel dosimeter; but its background R2 response was higher. In the second type, no difference in R2 response was seen in the dose ranges from 0 to 18 Gy. Both gels had a mass density between 0.35 and 0.45 g.cm-3 and CT values of about -650 to -750 Hounsfield units. Conclusion: It appeared that reactions between gelatin-free radicals and monomers, due to an increase in the gel temperature during rotation in the household mixer, led to a higher R2-background response. In the second type of gel, it seemed that the collapse of the nitrogen bubbles was the main factor that affected the R2-responses.
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Affiliation(s)
- Daryoush Shahbazi-Gahrouei
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mehrdad Gholami
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Tayyeb Allahverdi Pourfallah
- Department of Biophysics and Biochemistry, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Keshtkar
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Sedaghat M, Bujold R, Lepage M. Severe dose inaccuracies caused by an oxygen-antioxidant imbalance in normoxic polymer gel dosimeters. Phys Med Biol 2011; 56:601-25. [DOI: 10.1088/0031-9155/56/3/006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pourfallah TA, Allahverdi M, Alam NR, Ay MR, Zahmatkesh MH. Differential dose volume histograms of Gamma knife in the presence of inhomogeneities using MRI-polymer gel dosimetry and MC simulation. Med Phys 2009; 36:3002-12. [PMID: 19673199 DOI: 10.1118/1.3147256] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Polymer gel dosimeters offer a practical solution to 3D dose verification for conventional radiotherapy as well as intensity-modulated and stereotactic radiotherapy. In this study, EGSnrc calculated and PAGAT polymer gel dosimeter measured dose volume histograms (DVHs) for single-shot irradiations of the Gamma Knife (GK) unit were used to investigate the effects of the presence of inhomogeneities on 3D dose distribution. The head phantom was a custom-built 16 cm diameter Plexiglas sphere. Inside the phantom, there is a cubic cutout for inserting the gel vials and another cutout for inserting the inhomogeneities. Following irradiation with the GK unit, the polymer gel phantoms were scanned with a 1.5 T MRI scanner. Comparing the results of measurement in homogeneous and heterogeneous phantoms revealed that inserting inhomogeneities inside the homogeneous phantom did not cause considerable disturbances on dose distribution in irradiation with 8 mm collimator within low isodose levels (< 50%), which is essential for the dose sparing of sensitive structures. The results of simulation for homogeneous and inhomogeneous phantoms in irradiation with 18 mm collimator of the GK unit showed 23.24% difference in DVH within 90%-100% relative isodose level and also revealed that a significant part of the target (28.56%) received relative doses higher than the maximum dose, which exceeds the acceptance criterion (5%). Based on these results it is concluded that the presence of inhomogeneities inside the phantom can cause considerable errors in dose calculation within high isodose levels with respect to LGP prediction which assumes that the target is a homogeneous material. Moreover, it is demonstrated that the applied MC code is an accurate and stand-alone tool for 3D evaluation of dose distribution in irradiation with the GK unit, which can provide important, 3D plan evaluation criteria used in clinical practice.
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Affiliation(s)
- Tayyeb Allahverdi Pourfallah
- Department of Biochemistry and Biophysics, Faculty of Medicine, Mazandaran University of Medical Sciences, 48175-1665 Sari, Iran
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Performance evaluation of MRI-based PAGAT polymer gel dosimeter in an inhomogeneous phantom using EGSnrc code on a Co-60 machine. Appl Radiat Isot 2009; 67:186-91. [DOI: 10.1016/j.apradiso.2008.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 07/31/2008] [Accepted: 09/08/2008] [Indexed: 11/17/2022]
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Noda S, Suzuki Y, Hoshino Y, Furukawa S, Katoh H, Kurotaki K, Nakano T. Clinical application of the Fricke-glucomannan gel dosimeter for high-dose-rate (192)Ir brachytherapy. Phys Med Biol 2008; 53:3985-93. [PMID: 18596369 DOI: 10.1088/0031-9155/53/14/016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study investigates the efficacy of a new Fricke dosimeter formulation consisting of a standard Fricke gel dosimeter gelled with glucomannan (FrGDG). FrGDG was irradiated using a (192)Ir gamma-ray source with a remote afterloading system based on computed tomography images. (60)Co irradiation was performed for measuring the absorption of FrGDG and water. The distribution maps of T2 values from the irradiated containers were obtained by MR imaging and converted to the absorbed dose to visualize the dose distribution. We found that FrGDG was produced easily and quickly at room temperature. R2 (1/T2) values were reproducible and linearly correlated with the absorbed doses in the range from 0 to 30 Gy for irradiation with (192)Ir (the correlation coefficient was 0.99). The mean deviation between the doses obtained from the MR images of the FrGDG and those calculated by the treatment planning system for doses of 37.5, 40, 50, 62.5 and 75 Gy was 4.9%, 4.8%, 3.5%, 2.3% and 2.4%, respectively. In conclusion, MR imaging of FrGDG can visualize the dose distribution successfully, and thus serves as a useful quality assurance tool for complicated three-dimensional radiotherapy treatments.
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Affiliation(s)
- S Noda
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-22, Showa-machi, Maebashi, Gunma 371-8511, Japan
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Bayreder C, Schön R, Wieland M, Georg D, Moser E, Berg A. The spatial resolution in dosimetry with normoxic polymer-gels investigated with the dose modulation transfer approach. Med Phys 2008; 35:1756-69. [DOI: 10.1118/1.2898173] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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