Eyadeh Molham M, Rabaeh Khalid A, Aldweri Feras M, Al-Shorman Mohammad Y, Alheet Samer M, Awad Samer I, Hailat Tariq F
Physics Department, Faculty of Science, Yarmouk University, Irbid, 21163, Jordan.
Medical Imaging Department, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, 13115, Jordan.
Appl Radiat Isot. 2019 Nov;153:108812. doi: 10.1016/j.apradiso.2019.108812. Epub 2019 Jul 14.
A new formulation of hydrogel dosimeter consisting of ferrous-methylthymol blue (MTB)-polyvinyl alcohol (PVA) cross-linked chemically with glutaraldehyde (GTA) was studied and evaluated by nuclear magnetic resonance analysis by means of the R spin-spin relaxation rate. Previous optical studies of this transparent solid chemically cross-linked gel showed important dosimetric features in terms of sensitivity, auto-oxidation rate, and diffusion. This study shows that the MTB-PVA-GTA dosimeter has a reproducible linear dose response up to 40 Gy. For the optimum formulation of 0.1 mM MTB, 2.5% PVA, and 26.6 mM GTA, the measured R sensitivity was higher than that of traditional natural matrix-containing gels (MTB-gelatin) and all other reported PVA gel-based radiochromic dosimeters with MTB, xylenol orange (XO), or GTA (MTB-PVA, XO-PVA, XO-PVA-GTA). Additionally, the auto-oxidation rate was approximately ten times lower than that of the Fricke-MTB-gelatin system, which is consistent with the spectrophotometry results. The results of the independent experimental spectrophotometry and nuclear magnetic resonance analyses indicate that the transparent cross-linked dosimeter has good and consistent dosimetric features.
研究并通过核磁共振分析借助R自旋-自旋弛豫率评估了一种由亚铁甲基百里酚蓝（MTB）-聚乙烯醇（PVA）与戊二醛（GTA）化学交联而成的新型水凝胶剂量计。此前对这种化学交联透明固体凝胶的光学研究显示，其在灵敏度、自氧化速率和扩散方面具有重要的剂量学特征。本研究表明，MTB-PVA-GTA剂量计在高达40 Gy的剂量范围内具有可重复的线性剂量响应。对于0.1 mM MTB、2.5% PVA和26.6 mM GTA的最佳配方，测得的R灵敏度高于传统含天然基质的凝胶（MTB-明胶）以及所有其他报道的含MTB、二甲酚橙（XO）或GTA的基于PVA凝胶的放射变色剂量计（MTB-PVA、XO-PVA、XO-PVA-GTA）。此外，自氧化速率比弗里克-MTB-明胶体系低约十倍，这与分光光度法结果一致。独立实验的分光光度法和核磁共振分析结果表明，这种透明交联剂量计具有良好且一致的剂量学特征。
