Sandwall Peter A, Bastow Brandt P, Spitz Henry B, Elson Howard R, Lamba Michael, Connick William B, Fenichel Henry
Department of Radiation Oncology, OhioHealth, 330 Glessner Ave., Mansfield, OH 44903, USA.
Department of Chemistry, College of Arts and Sciences, University of Cincinnati, Cincinnati, OH 45221, USA.
Bioengineering (Basel). 2018 Jul 10;5(3):53. doi: 10.3390/bioengineering5030053.
Gel dosimeters are attractive detectors for radiation therapy, with properties similar to biological tissue and the potential to visualize volumetric dose distributions. Radio-fluorogenesis is the yield of fluorescent chemical products in response to energy deposition from ionizing radiation. This report shares the development of a novel radio-fluorogenic gel (RFG) dosimeter, gelatin infused with coumarin-3-carboxlyic acid (C3CA), for the quantification of imparted energy. Aqueous solutions exposed to ionizing radiation result in the production of hydroxyl free radicals through water radiolysis. Interactions between hydroxyl free radicals and coumarin-3-carboxylic acid produce a fluorescent product. 7-hydroxy-coumarin-3-carboxylic acid has a blue (445 nm) emission following ultra-violet (UV) to near UV (365⁻405 nm) excitation. Effects of C3CA concentration and pH buffers were investigated. The response of the RFG was explored with respect to strength, type, and exposure rate of high-energy radiation. Results show a linear dose response relationship independent of energy and type, with a dose-rate dependency. This report demonstrates increased photo-yield with high pH and the utility of gelatin-RFG for phantom studies of radiation dosimetry.
凝胶剂量计是放射治疗中颇具吸引力的探测器，其特性与生物组织相似，具备可视化体积剂量分布的潜力。辐射荧光生成是指荧光化学产物因电离辐射能量沉积而产生的产量。本报告介绍了一种新型辐射荧光凝胶（RFG）剂量计的研发情况，该剂量计是注入香豆素-3-羧酸（C3CA）的明胶，用于量化传递的能量。暴露于电离辐射的水溶液会通过水的辐射分解产生羟基自由基。羟基自由基与香豆素-3-羧酸之间的相互作用会产生一种荧光产物。7-羟基香豆素-3-羧酸在紫外（UV）至近紫外（365⁻405 nm）激发后发出蓝色（445 nm）荧光。研究了C3CA浓度和pH缓冲液的影响。探讨了RFG对高能辐射的强度、类型和照射率的响应。结果显示出与能量和类型无关的线性剂量响应关系，但存在剂量率依赖性。本报告证明了高pH值下光产率的提高以及明胶-RFG在辐射剂量学体模研究中的实用性。
