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Gayol A, Figueroa R, Guarda J, Leiva J, Leyton F, Malano F, Valente M. Effects on the accelerating electron bunches due to the presence of sulfur hexafluoride or air in the linac waveguide. Appl Radiat Isot 2024; 205:111155. [PMID: 38159451 DOI: 10.1016/j.apradiso.2023.111155] [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: 02/06/2023] [Revised: 11/08/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
Sulfur hexafluoride gas (SF6) is used as a dielectric insulator in the acceleration process of certain medical linear accelerator waveguides. Nevertheless, some innovative development and investigation cases require intervention in the linear accelerator or, specifically, on the waveguide, which could affect the sealing of the device. In this regard, vacuum sealing systems can be compromised, affecting the properties of the radiation beams produced. The presence of sulfur hexafluoride or air inside the VARIAN 6/100 waveguide was investigated under different pressure conditions and non-uniform electric fields, adapting Monte Carlo simulation techniques for modeling radiation transport coupled with electric fields. Obtained results indicated the suitability of the proposed approach, while comparisons with theoretical approaches and experimental evidence supported the model's consistency.
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Affiliation(s)
- A Gayol
- Instituto de Física Enrique Gaviola, CONICET & Laboratorio de Investigaciones e Instrumentación en Física Aplicada a La Medicina e Imágenes por Rayos X - LIIFAMIRx, FAMAF, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
| | - R Figueroa
- Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile; Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco, 4780000, Chile
| | - J Guarda
- Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile
| | - J Leiva
- Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile
| | - F Leyton
- Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile
| | - F Malano
- Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile; Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco, 4780000, Chile
| | - M Valente
- Instituto de Física Enrique Gaviola, CONICET & Laboratorio de Investigaciones e Instrumentación en Física Aplicada a La Medicina e Imágenes por Rayos X - LIIFAMIRx, FAMAF, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina; Centro de Física e Ingeniería en Salud CFIS, Universidad de La Frontera, Temuco, 4780000, Chile; Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco, 4780000, Chile.
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Gayol A, Malano F, Ribo Montenovo C, Pérez P, Valente M. Dosimetry Effects Due to the Presence of Fe Nanoparticles for Potential Combination of Hyperthermic Cancer Treatment with MRI-Based Image-Guided Radiotherapy. Int J Mol Sci 2022; 24:ijms24010514. [PMID: 36613959 PMCID: PMC9820326 DOI: 10.3390/ijms24010514] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/03/2022] [Accepted: 12/06/2022] [Indexed: 12/29/2022] Open
Abstract
Nanoparticles have proven to be biocompatible and suitable for many biomedical applications. Currently, hyperthermia cancer treatments based on Fe nanoparticle infusion excited by alternating magnetic fields are commonly used. In addition to this, MRI-based image-guided radiotherapy represents, nowadays, one of the most promising accurate radiotherapy modalities. Hence, assessing the feasibility of combining both techniques requires preliminary characterization of the corresponding dosimetry effects. The present work reports on a theoretical and numerical simulation feasibility study aimed at pointing out preliminary dosimetry issues. Spatial dose distributions incorporating magnetic nanoparticles in MRI-based image-guided radiotherapy have been obtained by Monte Carlo simulation approaches accounting for all relevant radiation interaction properties as well as charged particles coupling with strong external magnetic fields, which are representative of typical MRI-LINAC devices. Two main effects have been evidenced: local dose enhancement (up to 60% at local level) within the infused volume, and non-negligible changes in the dose distribution at the interfaces between different tissues, developing to over 70% for low-density anatomical cavities. Moreover, cellular uptakes up to 10% have been modeled by means of considering different Fe nanoparticle concentrations. A theoretical temperature-dependent model for the thermal enhancement ratio (TER) has been used to account for radiosensitization due to hyperthermia. The outcomes demonstrated the reliability of the Monte Carlo approach in accounting for strong magnetic fields and mass distributions from patient-specific anatomy CT scans to assess dose distributions in MRI-based image-guided radiotherapy combined with magnetic nanoparticles, while the hyperthermic radiosensitization provides further and synergic contributions.
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Affiliation(s)
- Amiel Gayol
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Francisco Malano
- Centro de Excelencia de Física e Ingeniería en Salud (CFIS), Departamento de Ciencias Físicas, Universidad de La Frontera, Av. Salazar 01145, Casilla 54D, Temuco 4811230, Chile
- Correspondence: (F.M.); (M.V.)
| | - Clara Ribo Montenovo
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Pedro Pérez
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Mauro Valente
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Centro de Excelencia de Física e Ingeniería en Salud (CFIS), Departamento de Ciencias Físicas, Universidad de La Frontera, Av. Salazar 01145, Casilla 54D, Temuco 4811230, Chile
- Correspondence: (F.M.); (M.V.)
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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: 8] [Impact Index Per Article: 4.0] [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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Soliman YS, Tadros SM, Beshir WB, Saad GR, Gallo S, Ali LI, Naoum MM. Study of Ag Nanoparticles in a Polyacrylamide Hydrogel Dosimeters by Optical Technique. Gels 2022; 8:gels8040222. [PMID: 35448123 PMCID: PMC9030572 DOI: 10.3390/gels8040222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 12/10/2022] Open
Abstract
The dosimetric characteristics of hydrogel dosimeters based on polyacrylamide (PAC) as a capping agent incorporating silver nitrate as a radiation-sensitive material are investigated using UV-Vis spectrophotometry within the dose range 0–100 Gy. Glycerol was used in the hydrogel matrix to promote the dosimetric response and increase the radiation sensitivity. Upon exposing the PAC hydrogel to γ-ray, it exhibits a Surface Plasmon Resonance (SPR) band at 453 nm, and its intensity increases linearly with absorbed doses up to 100 Gy. The results are compared with the silver nitrate gel dosimeter. Glycerol of 15% in the hydrogel matrix enhances the radiation sensitivity by about 30%. PAC hydrogel dosimeter can be considered a near water equivalent material in the 400 keV–20 MeV photon energy range. At doses less than 15 Gy, the PAC hydrogel dosimeter retains higher radiation sensitivity than the gel dosimeter. The total uncertainty (2σ) of the dose estimated using this hydrogel is about 4%. These results may support the validity of using this hydrogel as a dosimeter to verify radiotherapy techniques and dose monitoring during blood irradiation.
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Affiliation(s)
- Yasser S. Soliman
- National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo 11787, Egypt; (Y.S.S.); (W.B.B.)
| | - Soad M. Tadros
- Chemistry Department, Faculty of Education, Ain Shams University, Cairo 11566, Egypt;
- Correspondence:
| | - Wafaa B. Beshir
- National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo 11787, Egypt; (Y.S.S.); (W.B.B.)
| | - Gamal R. Saad
- Chemistry Department, Faculty of Science, Cairo University, Cairo 12613, Egypt; (G.R.S.); (M.M.N.)
| | - Salvatore Gallo
- Physics Department, “Aldo Pontremoli” Milano University, 20133 Milan, Italy;
| | - Laila I. Ali
- Chemistry Department, Faculty of Education, Ain Shams University, Cairo 11566, Egypt;
| | - Magdi M. Naoum
- Chemistry Department, Faculty of Science, Cairo University, Cairo 12613, Egypt; (G.R.S.); (M.M.N.)
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How Xylenol Orange and Ferrous Ammonium Sulphate Influence the Dosimetric Properties of PVA–GTA Fricke Gel Dosimeters: A Spectrophotometric Study. Gels 2022; 8:gels8040204. [PMID: 35448105 PMCID: PMC9025870 DOI: 10.3390/gels8040204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/17/2022] [Accepted: 03/19/2022] [Indexed: 11/19/2022] Open
Abstract
The development of Fricke gel (FG) dosimeters based on poly(vinyl alcohol) (PVA) as the gelling agent and glutaraldehyde (GTA) as the cross-linker has enabled significant improvements in the dose response and the stability over time of spatial radiation dose distributions. However, a standard procedure for preparing FG in terms of reagent concentrations is still missing in the literature. This study aims to investigate, by means of spectrophotometric analyses, how the sensitivity to the radiation dose and the range of linearity of the dose–response curve of PVA-GTA-FG dosimeters loaded with xylenol orange sodium salt (XO) are influenced by ferrous ammonium sulphate (FAS) and XO concentrations. Moreover, the effect of different concentrations of such compounds on self-oxidation phenomena in the dosimeters was evaluated. PVA-GTA-FG dosimeters were prepared using XO concentrations in the range 0.04–0.80 mM and FAS in the range 0.05–5.00 mM. The optical absorbance properties and the dose response of FG were investigated in the interval 0.0–42.0 Gy. The results demonstrate that the amount of FAS and XO determines both the sensitivity to the absorbed dose and the interval of linearity of the dose–response curve. The study suggests that the best performances of FG dosimeters for spectrophotometric analyses can be obtained using 1.00–0.40 mM and 0.200–0.166 mM concentrations of FAS and XO, respectively.
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Dosimetric investigations on radiation-induced Ag nanoparticles in a gel dosimeter. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07776-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Romero M, Macchione MA, Mattea F, Strumia M. The role of polymers in analytical medical applications. A review. Microchem J 2020. [DOI: 10.1016/j.microc.2020.105366] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Dosimetric properties of sulfosalicylic acid-ferrous-polyvinyl alcohol-glutaraldehyde hydrogel dosimeters using magnetic and optical techniques. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.109106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Eyadeh MM, Rabaeh KA, Aldweri FM, Al-Shorman MY, Alheet SM, Awad SI, Hailat TF. Nuclear magnetic resonance analysis of a chemically cross-linked ferrous-methylthymol blue-polyvinyl alcohol radiochromic gel dosimeter. Appl Radiat Isot 2019; 153:108812. [PMID: 31336352 DOI: 10.1016/j.apradiso.2019.108812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 07/04/2019] [Accepted: 07/12/2019] [Indexed: 11/29/2022]
Abstract
A new formulation of hydrogel dosimeter consisting of ferrous-methylthymol blue (MTB)-polyvinyl alcohol (PVA) cross-linked chemically with glutaraldehyde (GTA) was studied and evaluated by nuclear magnetic resonance analysis by means of the R2 spin-spin relaxation rate. Previous optical studies of this transparent solid chemically cross-linked gel showed important dosimetric features in terms of sensitivity, auto-oxidation rate, and diffusion. This study shows that the MTB-PVA-GTA dosimeter has a reproducible linear dose response up to 40 Gy. For the optimum formulation of 0.1 mM MTB, 2.5% PVA, and 26.6 mM GTA, the measured R2 sensitivity was higher than that of traditional natural matrix-containing gels (MTB-gelatin) and all other reported PVA gel-based radiochromic dosimeters with MTB, xylenol orange (XO), or GTA (MTB-PVA, XO-PVA, XO-PVA-GTA). Additionally, the auto-oxidation rate was approximately ten times lower than that of the Fricke-MTB-gelatin system, which is consistent with the spectrophotometry results. The results of the independent experimental spectrophotometry and nuclear magnetic resonance analyses indicate that the transparent cross-linked dosimeter has good and consistent dosimetric features.
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Affiliation(s)
- Molham M Eyadeh
- Physics Department, Faculty of Science, Yarmouk University, Irbid, 21163, Jordan
| | - Khalid A Rabaeh
- Medical Imaging Department, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, 13115, Jordan.
| | - Feras M Aldweri
- Physics Department, Faculty of Science, The Hashemite University, Zarqa, 13115, Jordan
| | | | - Samer M Alheet
- Radiotherapy Department, King Hussein Cancer Center, Amman, 11941, Jordan
| | - Samer I Awad
- Biomedical Engineering Department, Faculty of Engineering, The Hashemite University, Zarqa, 13115, Jordan
| | - Tariq F Hailat
- Doctoral School of Physics, ELTE Eötvös Loránd University, Budapest, Hungary and Radiation Biophysics Group, MTA Centre for Energy Research, Budapest, 1518, Hungary
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