Novel GTA-PVA Fricke gels for three-dimensional dose mapping in radiotherapy

D’Errico, Francesco; Lazzeri, Luigi; Dondi, Daniele; Mariani, Mario; Marrale, Maurizio; Souza, S.O.; Gambarini, G.

doi:10.1016/j.radmeas.2017.07.003

Cited by 53 publications

(31 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The PVA Mowiol ® 18-88, produced by Sigma-Aldrich, was employed in this experiment. The complete dissolution of Mowiol ® 18-88 in water can be easily obtained in approximately 40 minutes at 70°C, without the use of proper equipment required for other PVA compounds, as autoclave [30,38] or open vessel microwave digestion [32,37]. The other components used to prepare the PVA-GTA Fricke gel dosimeters were: Ferrous ammonium sulfate hexahydrate (FAS, Carlo Erba), Xylenol Orange tetrasodium sodium salt (XO, Riedel-de Haën), Glutaraldehyde (GTA, Sigma-Aldrich), and Sulfuric acid (SA, Sigma-Aldrich).…”

Section: Samples Preparationmentioning

confidence: 99%

Temperature behavior of radiochromic poly(vinyl-alcohol)-glutaraldehyde Fricke gel dosimeters in practice

Gallo

Lizio

Monti

et al. 2020

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

The use of synthetic gel matrices prepared with poly(vinyl-alcohol) (PVA) cross-linked by glutaraldehyde (GTA) contributed to enhance the interest toward radiochromic Fricke gel (FG) dosimeters. As it occurs in several chemical dosimeters, the response of PVA-GTA Fricke gels could be affected by temperature. Aim of this work is to study the dependence of the dosimetric properties of PVA-GTA Fricke gel dosimeters both on the irradiation temperature and on temperature changes possibly occurring between the irradiation and readout phases. Such effects were investigated by means of magnetic resonance imaging (MRI) and optical absorbance (OA) measurements.

show abstract

Section: Samples Preparationmentioning

confidence: 99%

Temperature behavior of radiochromic poly(vinyl-alcohol)-glutaraldehyde Fricke gel dosimeters in practice

Gallo

Lizio

Monti

et al. 2020

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Também se podem utilizar agentes de reticulação externos, mas esta é problemática por causa da complexidade química e estrutural da gelatina. Um outro inconveniente encontrado nas formulações de gelatina é a sua degradação ao longo do tempo 87 .…”

Section: Dosimetria Tridimensional (3d)unclassified

“…Por causa das limitações da gelatina e da agarose listadas, além de evidências promissoras, pesquisas recentes focam em géis de álcool polivinílico (PVA) 87 . PVA é um polímero com uma estrutura química simples, solúvel em água, não tóxico, barato e adequado para a fabricação de hidrogéis por meio de rotas físicas ou químicas.…”

Section: Dosimetria Tridimensional (3d)unclassified

See 1 more Smart Citation

Novos Materiais Dosimétricos para Aplicações em Física Médica

Souza¹,

Souza²,

Baffa

et al. 2019

Rev Bras Fis Med

Self Cite

View full text Add to dashboard Cite

24 IntroduçãoDosimetria é a determinação da exposição ou da dose de radiação em um ponto de um meio específico, que pode ser o ambiente ou o corpo de um indivíduo. Embora a dosimetria de radiação ionizante seja uma atividade presente em áreas diversas, incluindo saúde, indústria, aviação, por exemplo, é na área da saúde que os procedimentos dosimétricos são mais disseminados, porque o princípio ALARA deve ser sempre praticado.Pesquisas sobre novos materiais e metodologias para emprego em procedimentos dosimétricos estão em franco desenvolvimento. No Brasil, vários grupos de pesquisa têm contribuído para o desenvolvimento de materiais dosimétricos e metodologias para uso desses Novos materiais dosimétricos para aplicações em física médica Resumo Este artigo apresenta o estado da arte dos materiais dosimétricos para aplicações em dosimetria pessoal e clínica. O objetivo é fornecer uma visão geral das vantagens e limitações dos dosímetros comerciais disponíveis mais usados, bem como novos materiais estudados na atualidade. Resumimos trabalhos recentes publicados sobre materiais cristalinos e vítreos mais discutidos e com melhores perspectivas para uso prático em dosimetria por Termoluminescência (TL), Luminescência Opticamente Estimulada (OSL), Radiofotoluminescência (RPL) e Ressonância de Spin Eletrônico (ESR), e ainda géis, dosímetros plásticos e emulsões superaquecidas. São tratadas novas formas de uso desses materiais, como fibras para dosimetria ativa, filmes dosimétricos para dosimetria 2D, e materiais que possam ser usados em dosimetria tridimensional. Os trabalhos atuais demonstram uma clara tendência da opção do uso cada vez maior de optoeletrônica para obtenção dos sinais e sua leitura. Palavras-chave: materiais dosimétricos; dosímetros; dosimetria pessoal; dosimetria clínica. AbstractThis paper presents the state-of-the-art of dosimetric materials for personal and clinical dosimetry applications. The objective is to provide an overview of the advantages and limitations of the most commonly used commercial dosimeters, as well as new materials currently studied. We summarize recent work published on crystalline and vitreous materials more discussed and with better perspectives for practical use in dosimetry by Thermoluminescence (TL), Optically Stimulated Luminescence (OSL), Radiophotoluminescence (RPL), and Electron Spin Resonance (ESR), as well as gels, plastic dosimeters, and superheated emulsions. New forms of use of these materials are treated, such as fibers for active dosimetry, dosimetric films for 2D dosimetry, and materials that can be used in three-dimensional dosimetry. Current works demonstrate a clear tendency of the option of the increasing use of optoelectronics to obtain the signals and read them.

show abstract

“…Tetrazolium gellan gum gel dosimeters [11] and the newly proposed flexible polymer/silicone based dosimeters also rely on color changes during irradiation [12]. (2) “Fricke” types of gels are sensitive to the oxidation of ferrous to ferric ions during irradiation [13,14]. The change of oxidation status can be detected by optical methods in radiochromic gels or magnetic resonance imaging (MRI) using R1 = 1/T1 or R2 = 1/T2 contrast.…”

Section: Introductionmentioning

confidence: 99%

Basic Properties of a New Polymer Gel for 3D-Dosimetry at High Dose-Rates Typical for FFF Irradiation Based on Dithiothreitol and Methacrylic Acid (MAGADIT): Sensitivity, Range, Reproducibility, Accuracy, Dose Rate Effect and Impact of Oxygen Scavenger

et al. 2019

View full text Add to dashboard Cite

The photon induced radical-initiated polymerization in polymer gels can be used for high-resolution tissue equivalent dosimeters in quality control of radiation therapy. The dose (D) distribution in radiation therapy can be measured as a change of the physical measurement parameter T2 using T2-weighted magnetic resonance imaging. The detection by T2 is relying on the local change of the molecular mobility due to local polymerization initiated by radicals generated by the ionizing radiation. The dosimetric signals R2 = 1/T2 of many of the current polymer gels are dose-rate dependent, which reduces the reliability of the gel for clinical use. A novel gel dosimeter, based on methacrylic acid, gelatin and the newly added dithiothreitol (MAGADIT) as an oxygen-scavenger was analyzed for basic properties, such as sensitivity, reproducibility, accuracy and dose-rate dependence. Dithiothreitol features no toxic classification with a difference to THPC and offers a stronger negative redox-potential than ascorbic acid. Polymer gels with three different concentration levels of dithiothreitol were irradiated with a preclinical research X-ray unit and MR-scanned (T2) for quantitative dosimetry after calibration. The polymer gel with the lowest concentration of the oxygen scavenger was about factor 3 more sensitive to dose as compared to the gel with the highest concentration. The dose sensitivity (α = ∆R2/∆D) of MAGADIT gels was significantly dependent on the applied dose rate trueD˙ (≈48% reduction between trueD˙ = 0.6 Gy/min and trueD˙ = 4 Gy/min). However, this undesirable dose-rate effect reduced between 4–8 Gy/min (≈23%) and almost disappeared in the high dose-rate range (8 ≤ D˙≤ 12 Gy/min) used in flattening-filter-free (FFF) irradiations. The dose response varied for different samples within one manufacturing batch within 3%–6% (reproducibility). The accuracy ranged between 3.5% and 7.9%. The impact of the dose rate on the spatial integrity is demonstrated in the example of a linear accelerator (LINAC) small sized 5 × 10 mm2 10 MV photon field. For MAGADIT the maximum shift in the flanks in this field is limited to about 0.8 mm at a FFF dose rate of 15 Gy/min. Dose rate sensitive polymer gels likely perform better at high dose rates; MAGADIT exhibits a slightly improved performance compared to the reference normoxic polymer gel methacrylic and ascorbic acid in gelatin initiated by copper (MAGIC) using ascorbic acid.

show abstract

Novel GTA-PVA Fricke gels for three-dimensional dose mapping in radiotherapy

Cited by 53 publications

References 30 publications

Temperature behavior of radiochromic poly(vinyl-alcohol)-glutaraldehyde Fricke gel dosimeters in practice

Temperature behavior of radiochromic poly(vinyl-alcohol)-glutaraldehyde Fricke gel dosimeters in practice

Novos Materiais Dosimétricos para Aplicações em Física Médica

Basic Properties of a New Polymer Gel for 3D-Dosimetry at High Dose-Rates Typical for FFF Irradiation Based on Dithiothreitol and Methacrylic Acid (MAGADIT): Sensitivity, Range, Reproducibility, Accuracy, Dose Rate Effect and Impact of Oxygen Scavenger

Contact Info

Product

Resources

About