GEL FOR 3D DOSIMETRY BY OPTICAL TOMOGRAPHIC DENSITOMETRY

用于通过光学断层扫描密度测定进行 3D 剂量测定的凝胶

基本信息

批准号：
2108046
负责人：
MAREK J MARYANSKI
金额：
$ 7.55万
依托单位：
MGS RESEARCH, INC.
依托单位国家：
美国
项目类别：
财政年份：
1994
资助国家：
美国
起止时间：
1994-09-01 至 1995-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2108046
关键词：
GEL 3D DOSIMETRY OPTICAL TOMOGRAPHIC

项目摘要

This project aims to develop a novel, tissue-equivalent gel-dosimeter of ionizing radiation, which is capable of producing highly-resolved and accurate data on three dimensional dose distributions using optical tomographic densitometry. The dose-response mechanism relies on the production of Rayleigh scattering micro-particles in the gel at the site of radiation absorption, where acrylic comonomers dispersed in the gel are polymerized. Absorption and scattering of collimated light passing through the optically turbid medium produces a net attenuation of light intensity that can be measured and is directly related to the dose. Measurements of the projections of the optical density into different directions can be used to reconstruct the distribution of radiation doses within the gel. Doses of the order of 10 Gy can be measured with a spatial resolution <1mm. In previous work, the MRI properties of the gel have been investigated and used very successfully to create 3D dose maps, but there are significant advantages to the use of a simpler optical method of reading the dose distribution stored by the gel. The gel will find widespread use in radiation therapy practice, for 3D measurements in homogeneous and anthropomorphic phantoms, confirmation of computerized treatment planning and in quality assurance procedures. The goals of Phase I are to devise and evaluate a protocol for convenient and inexpensive preparation of a prototype polymer-gel dosimeter optimized for optical densitometry, to demonstrated its stability and reproducibility as well as spatial uniformity of the dose-response, and to evaluate the feasibility of constructing a low-cost bench top optical scanner for the reconstruction of 3D dose distributions. These studies will prepare the ground for the development of more efficient polymer-gels and an optical reader in Phase II. PROPOSED COMMERCIAL APPLICATION: Estimated 5000 polymer-gels could be distributed annually. This estimate is based upon (a) 30 new accelerators per year, and 40 X-ray and electron beam field; (b) over 3000 existing treatment machines will use 10 gels per year for dosimetry; (c ) research centers might use 5 gels annually for non-routine dose distributions. The annual sales of the gels alone could produce $1,000,000 sales. In addition, if the optical device is available for a cost of $50,000, then 20 such devices per year could be sold, comparable to the number of "water-tank" systems that are in current use.

该项目旨在开发一种新型的，等效的电离辐射凝胶仪，该辐射能够使用光学层析成分测定法对三维剂量分布产生高度分辨和准确的数据。剂量反应机制依赖于辐射吸收部位的凝胶中雷利散射微粒的产生，在凝胶中，丙烯酸联合体分散在凝胶中。穿过光学浊度介质的准直光吸收和散射产生的光强度净衰减，可以测量并直接与剂量相关。光密度对不同方向的投影的测量可用于重建凝胶中辐射剂量的分布。可以用空间分辨率<1mm来测量10 Gy阶的剂量。在先前的工作中，已经研究并非常成功地使用了凝胶的MRI特性来创建3D剂量图，但是使用更简单的光学方法来读取凝胶存储的剂量分布的优势有显着优势。该凝胶将在放射治疗实践中发现广泛使用，用于在均质和拟人化幻影中进行3D测量，确认计算机治疗计划以及质量保证程序。第一阶段的目标是设计和评估一项协议，以方便且廉价地制备用于光学密度测定法优化的原型聚合物 - 凝胶剂量表，以证明其稳定性和可重复性以及剂量响应的空间均匀性，并评估用于恢复效率低下的bepoltical scannner的可行性。这些研究将为开发更有效的聚合物 - 凝胶和II期光学读取器做准备。拟议的商业应用：估计每年可以分发5000个聚合物凝胶。该估计值基于（a）每年30个新的加速器，以及40张X射线和电子束场；（b）超过3000台现有的治疗机将每年使用10粒剂量剂量；（c）研究中心可能每年使用5粒剂量进行非列剂量分布。仅凝胶的年销售额就可以产生1,000,000美元的销售额。此外，如果光学设备的成本为50,000美元，则每年可以出售20种此类设备，与当前使用中的“水坦克”系统的数量相当。