Radiochromic Films for the Two-Dimensional Dose Distribution Assessment

PVA/PEG/EY samples were irradiated using of 50 KGy, gamma radiation dose. To investigate the effects of irradiation on the optical properties of the blend, UV-vis spectroscopy is used to study 6 samples of the blend, with different PEG content, 0, 1, 3, 5, 10, 15 percent, before and after irradiation. Radiation effects manifest itself as many changes in the following parameters: The absorption for all sample decreases after irradiation, the direct and indirect energy gap value increases after irradiation, the values of the extinction coefficient decrease after irradiation. The values of the extinction coefficient, k, of the nonirradiated samples are decreased or increased depending on the PEG content, while it increased for all irradiated samples despite of the PEG content. The refractive index, n, increases with increasing PEG concentration for irradiated and nonirradiated samples. The main changes occurred in the optical parameters after irradiation are: an increase in the values of the dispersion energy parameter, Ed, an increase in the single oscillator energy Eo, an immense decrease in the average oscillator strength, So, a large increase in the ratio of the effective number of carrier concentration to the effective mass of the electron (e2 /πc2). The values of the real and imaginary parts of the optical permittivity of irradiated samples are less than nonirradiated samples. The optical conductivity, σopt, increase for all irradiated samples. The values of O.D, are changing in four specific regions. The decrease and increase in O.D values depend on the variation in absorbance values which depend on PEG concentrations, and the role of irradiation in changing the absorbance of the blend.

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“…The net optical density includes all factors affecting the change in the color of the RCF [24] [25]. As presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

Effect of gamma radiation on optical properties of PVA/PEG/EY blend, and radiochromism.

Alibwaini

Ajlouni

Sharshar

et al. 2022

Preprint

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“…The active layer is symmetrically sandwiched between two 125 μm thick matte polyester substrates. The active layer and the polyester substrates in the EBT-XD film are thinner than those in the EBT3 film (active layer: 28 μm; polyester substrate: 125 μm) [3].…”

Section: Introductionmentioning

confidence: 95%

“…All the irradiated films used in this study were scanned after 48 hours post-irradiation using a Microtek ScanMaker 1000 XL (Taiwan) flatbed scanner. The transmission mode was set according to the set-up by [3,4] at the scanner including scan resolution of 75 dots per inch (dpi), a 48bit TIFF image (16 bits per channel) and all available image correction methods turned off. All film pieces were positioned at the same location in the centre of the scanning area.…”

Section: Scanning Protocol and Analysismentioning

confidence: 99%

Dose Mapping of Gamma Irradiation Chamber (Gic)

M.N¹,

M.R²,

A³

et al. 2022

AJMedTech

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The use of gamma rays to irradiate blood products have been demonstrated to reduce the probability of post-transfusion graft versus host disease. The aim of this study is to investigate the accuracy of a new batch of Gafchromic EBT-XD films to map the homogeneity of gamma radiation dose delivered to the blood bags and identify the lowest and highest levels of radiation exposure to the blood. The Gammacell 3000 Elan Gamma irradiation chamber (GIC) @ Blood Irradiator with Cesium-137 source was used. During the gamma irradiation at an exposure of 8 minutes 51 seconds to deliver a central dose of 25 Gy to the film, the EBT-XD films were placed at the centre of a blood-equivalent phantom. The doses then were measured using dose mapping analysis of Gafchromic EBT-XD film. The responses of EBT-XD films were compared with EBT3 films and GS 300 Dose Mapping Report 2021 prepared by Best Theratronics Dosimetry Laboratory, Canada. Results showed the value of doses obtained from the mapping using EBT-XD were reliable compared with the doses measured in EBT3 film as they were in the range of the acceptable dose ranges for blood irradiation procedures. The mapping with EBT-XD film yielded a minimum dosage of 18 Gy and a maximum exposure of 32 Gy at 8 minutes 51 seconds of irradiation. In conclusion, EBT-XD offered excellent dosimetric characteristics and has a the potential to dose map the blood irradiator.

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“…An electrometer quantifies the charges from the ion pairs produced within the gas. The film dosimeter consists of a radiosensitive thin layer, which darkens upon irradiation due to the polymerisation in a radiochromic dosimeter and emulsion in a radiographic dosimeter [ 25 , 26 ]. The film dosimeter can be read using a film scanner, transmission densitometers, or spectrophotometers [ 27 ].…”

Section: Introductionmentioning

confidence: 99%

A Review of PRESAGE Radiochromic Polymer and the Compositions for Application in Radiotherapy Dosimetry

et al. 2022

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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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Radiochromic Films for the Two-Dimensional Dose Distribution Assessment

Cited by 23 publications

References 109 publications

Effect of gamma radiation on optical properties of PVA/PEG/EY blend, and radiochromism.

Effect of gamma radiation on optical properties of PVA/PEG/EY blend, and radiochromism.

Dose Mapping of Gamma Irradiation Chamber (Gic)

A Review of PRESAGE Radiochromic Polymer and the Compositions for Application in Radiotherapy Dosimetry

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