Effect of inorganic salts and matrix crosslinking on the dose response of polymer gel dosimeters based on acrylamide
Effect of inorganic salts and matrix crosslinking on the dose response of polymer gel dosimeters based on acrylamide
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DOI：
10.1016/j.radmeas.2018.07.004
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发表时间：
2018-10-01
影响因子：
2
通讯作者：
Mattea, Facundo
中科院分区：
文献类型：
--
作者：
Chacon, David;Strumia, Miriam;Mattea, Facundo
在聚合物凝胶剂量计中使用添加剂来提高其灵敏度或改善其性能对其在放射医学中的应用具有重要意义。为此，无机盐被用作添加剂；然而，它们在剂量计中的存在导致其机械性能的严重改变，从而导致其维持稳定的剂量分布的能力随时间的变化。这一领域的大多数研究结论是，需要对影响剂量计机械性能的物种进行化学修饰，在大多数情况下，剂量计是明胶基质。在本研究中，用不同的无机盐，即氯化镁、氯化钙和氯化锰，对Pagat剂量计的明胶基质进行了共价交联。比较了这些材料与Pagat材料的力学性能、X射线灵敏度和剂量分布稳定性。结果表明，明胶结构的交联性和剂量学材料的灵敏度之间存在折衷。因此，必须考虑交联度和无机盐浓度的适当选择。通过加入浓度为1M的氯化镁和以0.08%w/v浓度的戊二醛交联明胶基质，得到了增强型剂量计。与Pagat相比，这种材料的灵敏度提高了75%，2D剂量分布的时间稳定性和空间稳定性相似。
The use of additives in polymer gel dosimeters to enhance their sensitivity or to improve their performance is of great importance for their application in radiomedicine. Inorganic salts have been used as additives with this purpose; however, their presence in the dosimeters induce severe modifications in their mechanical properties and consequently in their capabilities to maintain a stable dose distribution with time. Most studies in this area conclude in the need to use chemical modifications of the species responsible for the mechanical properties of the dosimeters, which in most cases is a gelatin matrix. In this study, a covalent crosslinking of the gelatin matrix of PAGAT dosimeters doped with different inorganic salts, namely MgCl2, CaCl2 and MnCl2 has been carried out. The mechanical properties, X-ray sensitivity and dose distribution stability in these materials were compared to those of PAGAT. The results indicated a compromise between the crosslinking of the gelatin structure and the sensitivity of the dosimetric material. Therefore, the proper selection of the degree of crosslinking and the inorganic salt concentration must be considered. An enhanced dosimeter was obtained by adding MgCl2 with a 1M concentration and by crosslinking the gelatin matrix with glutaraldehyde at a 0.08% w/v concentration. This material presented a 75% enhanced sensitivity relative to PAGAT and similar temporal stability and spatial stability in 2D dose distributions.