Radiation dose distributions in three dimensions from tomographic optical density scanning of polymer gels .1. Development of an optical scanner
Radiation dose distributions in three dimensions from tomographic optical density scanning of polymer gels .1. Development of an optical scanner
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DOI：
10.1088/0031-9155/41/12/009
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发表时间：
1996-12-01
影响因子：
3.5
通讯作者：
Schulz, RJ
中科院分区：
文献类型：
--
作者：
Gore, JC;Ranade, M;Schulz, RJ
本文提出了一种新的电离辐射剂量测定方法，即利用组织等效的聚合物凝胶来记录三维剂量分布。使用光学断层摄影密度测定法测量凝胶内存储的剂量测定数据。剂量-反应机制依赖于光散射微粒的产生，所述光散射微粒由分散在凝胶中的丙烯酸共聚单体的聚合产生。在被照射的光学混浊介质中由散射引起的准直光束的衰减与0-10戈伊范围内的辐射剂量直接相关。一种光学扫描仪已经开发，它结合了氦氖激光器，光电二极管检测器，和旋转凝胶平台。使用安装在平移台上的镜子，激光束在平台的每次增量旋转之间扫描穿过凝胶。使用所获得的光密度投影的集合，然后重建辐射场的横截面图像。使用目前的原型扫描仪，可以测量0-10戈伊范围内的剂量，精确度优于5%，空间分辨率约为2 mm。该方法可用于确定辐照凝胶中的三维剂量分布，包括测量由多叶准直器、动态楔形和立体定向治疗产生的复杂分布，以及用于质量保证程序。
A new method of dosimetry of ionizing radiations has been developed that makes use of tissue-equivalent polymer gels which are capable of recording three-dimensional dose distributions. The dosimetric data stored within the gels are measured using optical tomographic densitometry. The dose-response mechanism relies on the production of light scattering microparticles which result from the polymerization of acrylic comonomers dispersed in the gel. The attenuation of a collimated Light beam caused by scattering in the irradiated optically turbid medium is directly related to the radiation dose over the range 0-10 Gy. An optical scanner has been developed which incorporates an He-Ne laser, photodiode detectors, and a rotating gel platform. Using mirrors mounted on a translating stage, the laser beam scans across the gel between each incremental rotation of the platform. Using the set of optical density projections obtained, a cross sectional image of the radiation field is then reconstructed. Doses in the range 0-10 Gy can be measured to better than 5% accuracy with a spatial resolution approximate to 2 mm using the current prototype scanner. This method can be used for the determination of three-dimensional dose distributions in irradiated gels, including measurements of the complex distributions produced by multi-leaf collimators, dynamic wedge and stereotactic treatments, and for quality assurance procedures.