STORAGE PHOSPHOR FILM FOR RADIATION THERAPY DOSIMETRY

现代放射治疗方式，例如调强放射治疗(IMRT)，是相关的 具有高度保角的剂量分布和陡峭的梯度。这些模式的试运行需要 正在加紧研究和开发的多维剂量计的使用。最近的一份报告 来自放射物理中心(RPC)的调查显示，大约30%的机构未能提供剂量 分配给符合自己治疗计划的头颈部体模，至7%或4毫米以内。这个 RPC报告提供了强有力证据，表明IMRT实施容易出错且质量提高 需要保证工具。这项研究的主要假设是低Z KCl：Eu2+的储存 磷光薄膜(SPF)将提供第一个能够进行基准剂量测量的2D剂量计 测量，大大改善了放射治疗的调试和质量保证 治疗计划和交付系统。我们的第一个目标是优化KCl：Eu2+存储荧光粉颗粒 成分和化学结构，以最大限度地提高辐射敏感性、辐射硬度、响应一致性、 和信号稳定性。我们的第二个目标是开发一种工艺，通过蒸发优化的 目标1中使用物理气相沉积开发的厚度为一微米量级的存储荧光粉 在几乎等量于水的底物上。我们的第三个目标是证明SPF剂量计是在 AIM 2将提供基准质量的剂量分布测量，并展示 通过构建平面和圆柱形剂量计的SPF制造工艺。

Modern radiation therapy modalities, for example, intensity modulated radiation therapy (IMRT), are associated with highly conformal dose distributions with steep gradients. Commissioning of these modalities requires the use of multidimensional dosimeters which have been under intense research and development. A recent report from the Radiological Physics Center (RPC) revealed that roughly 30% of institutions failed to deliver a dose distribution to a head-and-neck phantom that agrees with their own treatment plan to within 7% or 4 mm. The RPC report provides strong evidence that IMRT implementation is prone to error and that improved quality assurance tools are required. The overarching hypothesis of this research is that a low-Z KCl:Eu2+ storage phosphor film (SPF) will provide the first 2D dosimeter capable of conducting benchmark dosimetry measurements, substantially improving the commissioning and quality assurance of radiation therapy treatment planning and delivery systems. Our first aim is to optimize KCl:Eu2+ storage phosphor particle composition and chemical structure to maximize radiation sensitivity, radiation hardness, response uniformity, and signal stability. Our second aim is to develop a process to fabricate an SPF by evaporating the optimized storage phosphor developed in aim 1 to a thickness on the order of one micron using physical vapor deposition onto a nearly water-equivalent substrate. Our third aim is to demonstrate that the SPF dosimeter developed in aim 2 will provide benchmark-quality dose distribution measurements and to demonstrate the flexibility of the SPF fabrication process by building planar and cylindrical dosimeters.