A thin film recording medium for use in food irradiation

Saylor, M.C; Tamargo, T.T.; McLaughlin, W.L.; Khan, Hasan M.; Lewis, David F.; Schenfele, R.D.

doi:10.1016/1359-0197(88)90222-6

Cited by 42 publications

(42 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A transition in the structure of the diacetylene backbone is accompanied by a shift in the absorption peaks, and by a change in length of polymer chain. 25 Such a rearrangement is observed in MD-55 with increased dose 10,21,26,27 and with temperature. 10,11,28 A shift in absorption peak with dose was not observed for EBT film, 12 which leads to a belief that the conformation of atoms comprising the polymer backbone of the LiPCDA polymer formed within EBT film is similar to the backbone of the monomer chain.…”

Section: Ia Chemical Background and General Experiencementioning

confidence: 88%

Temperature and hydration effects on absorbance spectra and radiation sensitivity of a radiochromic medium

et al. 2008

View full text Add to dashboard Cite

The effects of temperature on real time changes in optical density ͑⌬OD͒ of GAFCHROMIC ® EBT film were investigated. The spectral peak of maximum change in absorbance ͑ max ͒ was shown to downshift linearly when the temperature of the film was increased from 22 to 38°C. The ⌬OD values were also shown to decrease linearly with temperature, and this decrease could not be attributed to the shift in max . A compensation scheme using max and a temperature-dependent correction factor was investigated, but provided limited improvement. Part of the reason may be the fluctuations in hydration of the active component, which were found to affect both position of absorbance peaks and the sensitivity of the film. To test the effect of hydration, laminated and unlaminated films were desiccated. This shifted both the major and minor absorbance peaks in the opposite direction to the change observed with temperature. The desiccated film also exhibited reduced sensitivity to ionizing radiation. Rehydration of the desiccated films did not reverse the effects, but rather gave rise to another form of the polymer with absorbance maxima upshifted further 20 nm. Hence, the spectral characteristics and sensitivity of the film can be dependent on its history, potentially complicating both real-time and conventional radiation dosimetry.

show abstract

Section: Ia Chemical Background and General Experiencementioning

confidence: 88%

Temperature and hydration effects on absorbance spectra and radiation sensitivity of a radiochromic medium

et al. 2008

View full text Add to dashboard Cite

show abstract

“…These results were in good agreement with the finding of Giles and Murphy, 27 who had shown that XR type films are dose-rateindependent within 5%. In an independent investigation, Saylor et al 21 showed 5% variation in optical densities of HD-810 film for dose rates ranging from 0.02 to 200 Gy/ min. However, many of the reports in the literature pertain to older films that are not useful for current brachytherapy measurements.…”

Section: Iiib2 Radiochromic Filmmentioning

confidence: 99%

“…Advantages of EBT film compared to silver halide film include the following: relative energy insensitivity, insensitivity to visible light, selfdeveloping characteristics, greater tissue equivalency, and dose-rate independence. [20][21][22][23] Different investigators have noted up to 15% variation in the film response throughout a film that was exposed to a uniform dose of radiation. Sources for these uncertainties have been pointed out by Bouchard et al 24 Looking at two orthogonal directions, the film response is more uniform in one direction.…”

Section: Iiib2 Radiochromic Filmmentioning

confidence: 99%

A dosimetric uncertainty analysis for photon‐emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC‐ESTRO

et al. 2011

View full text Add to dashboard Cite

This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization ͑ISO͒ Guide to the Expression of Uncertainty in Measurement ͑GUM͒ and the National Institute of Standards and Technology ͑NIST͒ Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is covered first. Uncertainties in each of the brachytherapy dosimetry parameters of the TG-43 formalism are then explored, ending with transfer to the clinic and recommended approaches. Dosimetric uncertainties during treatment delivery are considered briefly but are not included in the detailed analysis. For low-and high-energy brachytherapy sources of low dose rate and high dose rate, a combined dosimetric uncertainty Ͻ5% ͑k =1͒ is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and source and treatment planning system manufacturers. These recommendations include the use of the GUM and NIST reports, a requirement of constancy of manufacturer source design, dosimetry investigator guidelines, provision of the lowest uncertainty for patient treatment dosimetry, and the establishment of an action level based on dosimetric uncertainty. These recommendations reflect the guidance of the American Association of Physicists in Medicine ͑AAPM͒ and the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology ͑GEC-ESTRO͒ for their members and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.

show abstract

“…For improvement of the system sensitivity of radiochromic film dosimetry, the peak wavelength of a scanner light source was tuned to the absorption peak of the radiochromic film [23][24][25][26]. Ranade et al [27] developed a 2D optical film scanner equipped with a red light-emitting diode suitable for the radiochromic film absorption peak.…”

Section: Introductionmentioning

confidence: 99%

Simulation for improvement of system sensitivity of radiochromic film dosimetry with different band-pass filters and scanner light intensities

Kamomae

Miyabe

Sawada

et al. 2011

Radiol Phys Technol

View full text Add to dashboard Cite

The delivered dose of high-energy photon beams is measured with radiochromic film. Previous studies sought to improve the system sensitivity of radiochromic film dosimetry by use of band-pass filters. However, band-pass filters reduce the scanning light intensity. To avoid a reduction of the signal-to-noise ratio, one must increase the scanner light intensity. Our purposes in this study were to develop an optical system model of GAFCHROMIC EBT2 radiochromic film dosimetry, and to estimate the system sensitivity characteristics by employing a combination of band-pass filters and scanner light intensities. The spectra of the scanner light source, band-pass filter, and irradiated EBT2 films were measured with a spectrometer. Meanwhile, the intensity of a light path from the scanner light source to the scanner detector was simulated. Then, the dose-response curves were computed with six simulated virtual band-pass filters of varying bandwidth. The simulated dose-response curves were in good agreement with the experimental values. The slope of the simulated dose-response curve was steeper when a filter of narrower bandwidth was used; however, at the same time, saturation was observed at a lower dose. For achieving the same dose response as was observed without a band-pass filter, it was necessary to increase the scanner light intensity. We proved that our proposed optical system model was valid, suggesting that a realistic simulation may be feasible with the proposed model. For improvement of the system sensitivity of radiochromic film dosimetry, it is necessary to select a well-balanced combination of band-pass filter and scanner light intensity.

show abstract

A thin film recording medium for use in food irradiation

Cited by 42 publications

References 12 publications

Temperature and hydration effects on absorbance spectra and radiation sensitivity of a radiochromic medium

Temperature and hydration effects on absorbance spectra and radiation sensitivity of a radiochromic medium

A dosimetric uncertainty analysis for photon‐emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC‐ESTRO

Simulation for improvement of system sensitivity of radiochromic film dosimetry with different band-pass filters and scanner light intensities

Contact Info

Product

Resources

About