Determination of effective atomic numbers from mass attenuation coefficients of tissue-equivalent materials in the energy range 60 keV-1.33 MeV

Amin, Noorfatin Aida Baharul; Zukhi, Jihan; Kabir, Norlaili A.; Zainon, Rafidah

doi:10.1088/1742-6596/851/1/012018

Cited by 5 publications

(2 citation statements)

References 8 publications

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“…The most reliable quantity to determine for the material is the mass attenuation coefficient measured with the same beam quality as that to be modulated. It is also verifiable that changes of elemental composition and or impurities within constituent elements of a material would affect the value of attenuation coefficient measured for the material with a particular beam quality [17]. Owing to uncertainties in the experimental setup for the measurement of the attenuation coefficient, it would be prudent for one to normalize the attenuation coefficient of a material to that of water measured with the same irradiation geometry.…”

Section: Discussionmentioning

confidence: 99%

Implementation of compensator-based intensity modulated radiotherapy with a conventional telecobalt machine using missing tissue approach

Tagoe

Mensah

Fletcher

2018

Polish Journal of Medical Physics and Engineering

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Objectives: The present study aimed to generate intensity-modulated beams with compensators for a conventional telecobalt machine, based on dose distributions generated with a treatment planning system (TPS) performing forward planning, and cannot directly simulate a compensator. Materials and Methods: The following materials were selected for compensator construction: Brass, Copper and Perspex (PMMA). Boluses with varying thicknesses across the surface of a tissue-equivalent phantom were used to achieve beam intensity modulations during treatment planning with the TPS. Beam data measured for specific treatment parameters in a full scatter water phantom with a 0.125 cc cylindrical ionization chamber, with a particular compensator material in the path of beams from the telecobalt machine, and that without the compensator but the heights of water above the detector adjusted to get the same detector readings as before, were used to develop and propose a semi-empirical equation for converting a bolus thickness to compensator material thickness, such that any point within the phantom would receive the planned dose. Once the dimensions of a compensator had been determined, the compensator was constructed using the cubic pile method. The treatment plans generated with the TPS were replicated on the telecobalt machine with a bolus within each beam represented with its corresponding compensator mounted on the accessory holder of the telecobalt machine. Results: Dose distributions measured in the tissue-equivalent phantom with calibrated Gafchromic EBT2 films for compensators constructed based on the proposed approach, were comparable to those of the TPS with deviation less than or equal to ± 3% (mean of 2.29 ± 0.61%) of the measured doses, with resultant confidence limit value of 3.21. Conclusion: The use of the proposed approach for clinical application is recommended, and could facilitate the generation of intensity-modulated beams with limited resources using the missing tissue approach rendering encouraging results.

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Section: Discussionmentioning

confidence: 99%

Implementation of compensator-based intensity modulated radiotherapy with a conventional telecobalt machine using missing tissue approach

Tagoe

Mensah

Fletcher

2018

Polish Journal of Medical Physics and Engineering

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“…Equations (1-2) calculate absorption and attenuation of photon radiations and entirely depends upon the effective atomic number of element or mixture (Noorfatin Aida et al, 2017).…”

Section: Methodsmentioning

confidence: 99%

Development of theoretical-computational model for radiation shielding

Khan

Khan²,

Almutairi

et al. 2020

Journal of Radiation Research and Applied Sciences

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Development of materials for radiation shielding application, which are lightweight, flexible, and robust increases in demand for nuclear radiation facilities including industrial or medical applications. In this paper, three metals (lead, gadolinium, bismuth) doped polymeric compounds (poly-acrylonitrile, polyethylene, and kevlar) were simulated by using theoretical and computational model. It was assumed that lead, gadolinium and bismuth were dispersed homogenously. Both theoretical and computational model were used to calculate the attenuation coefficients of these composite polymeric compounds. At first, theoretical calculations were performed and then computational models were used to simulate the irradiation of the polymeric compounds under various photon energy sources. For each compound, attenuation coefficients were calculated under different percentages and then compared with two computational programs. The work attains novelty as no work is ever reported on the metal/ polymeric composites for radiation shielding applications by theoretical-computational technique. This approach was used for the material selection and estimating the possibility of error and to calculate attenuation coefficients under various radiation doses. The research opens new grounds for developing radiation-shielding materials by computational techniques.

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Photon attenuation parameters for some tissues from Geant4 simulation, theoretical calculations and experimental data: a comparative study

Arslan

2019

NUCL SCI TECH

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Determination of effective atomic numbers from mass attenuation coefficients of tissue-equivalent materials in the energy range 60 keV-1.33 MeV

Cited by 5 publications

References 8 publications

Implementation of compensator-based intensity modulated radiotherapy with a conventional telecobalt machine using missing tissue approach

Implementation of compensator-based intensity modulated radiotherapy with a conventional telecobalt machine using missing tissue approach

Development of theoretical-computational model for radiation shielding

Photon attenuation parameters for some tissues from Geant4 simulation, theoretical calculations and experimental data: a comparative study

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