Enhancement of Dose Response and Nuclear Magnetic Resonance Image of PAGAT Polymer Gel Dosimeter by Adding Silver Nanoparticles

Abstract

In the present study, the normoxic polyacrylamide gelatin and tetrakis hydroxy methyl phosphoniun chloride (PAGAT) polymer gel dosimeters were synthesized with and without the presence of silver (Ag) nanoparticles. The amount of Ag nanoparticles varied from 1 to 3 ml with concentration 3.14 g/l, thus forming two types of PAGAT polymer gel dosimeters before irradiating them with 6 to 25 Gy produced by 1.25-MeV 60Co gamma rays. In this range, the predominant gamma ray interaction with matter is by Compton scattering effect, as the photoelectric absorption effect diminishes. MRI was employed when evaluating the polymerization of the dosimeters and the gray scale of the MRI film was determined via an optical densitometer. Subsequent analyses of optical densities revealed that the extent of polymerization increased with the increase in the absorbed dose, while the increase of penetration depth within the dosimeters has a reverse effect. Moreover, a significant increase in the optical density-dose response (11.82%) was noted for dosimeters containing 2 ml Ag nanoparticles.

Dosimetry and Radioenhancement Comparison of Gold Nanoparticles in Kilovoltage and Megavoltage Radiotherapy using MAGAT Polymer Gel Dosimeter

“…Consequently, the increase in doses in this energy and in the low concentrations of AuNPs is not justified based on e/g. In fact, owing to the dependence of the cross-section of the Compton scattering on the number of electrons in a specific thickness of the material, the important factor in the Compton attenuation is the number of electrons per cubic centimeter (e/cm 3 ), not e/g [37]. By comparing e/cm 3 of gold with water (4.66 ×10 24 e/cm 3 for gold and 3.34 ×10 23 e/cm 3 for water), the dose increase in 1.25 MeV is completely in line with expectations.…”

Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry

“…Recently, addition of high atomic elements (such as bismuth, gadolinium, silver or gold nanoparticles, etc.) has been investigated for increasing photon sensitivity [80][81][82][83][84][85][86][87][88][89][90][91][92].…”

Dosimetry and Radioenhancement Comparison of Gold Nanoparticles in Kilovoltage and Megavoltage Radiotherapy using MAGAT Polymer Gel Dosimeter

“…Consequently, the increase in doses in this energy and in the low concentrations of AuNPs is not justified based on e/g. In fact, owing to the dependence of the crosssection of the Compton scattering on the number of electrons in a specific thickness of the material, the important factor in the Compton attenuation is the number of electrons per cubic centimeter (e/cm 3 ), not e/g [37]. By comparing e/cm 3 of gold with water (4.66 ×10 24 e/ cm 3 for gold and 3.34 ×10 23 e/cm 3 for water), the dose increase in 1.25 MeV is completely in line with expectations.…”

“…The findings of the studies carried out in the dose enhancement of NPs exposed to megavoltage beams are contradictory [34,35]. Acceptable DEFs induced by various NPs under the irradiation of 6oCo γ-rays, in the investigations of Maggiorella, Sabbaghizadeh, and Deyhimihaghighi were in contradiction with the results of Ezzati, Kakade, and Toossi studies [36][37][38][39][40][41]. Therefore, in this study, we investigate the potential of 50 nm AuNPs as radio-enhancer in the decayed energy from the Co-60 source compared with the Ir-192 source, using the MAGAT gel dosimeter.…”