OPTICAL TOMOGRAPHY OF POLYMER GELS FOR 3D DOSIMETRY

用于 3D 剂量测定的聚合物凝胶光学断层扫描

基本信息

批准号：
2108049
负责人：
MAREK J MARYANSKI
金额：
$ 34.23万
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 1998-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2108049
关键词：
biomedical equipment development gel image processing personal computers polymers radiation dosage tomography

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 1 Gy can be measured with a spatial resolution <1mm. In Phase 1, basic optical properties of the gel have been investigated and a prototype optical scanner using a single laser beam and scanning photodiode was constructed and used successfully to create accurate 2D dose maps. The goals of Phase 2 are to reengineer the optical tomography apparatus in order to perform 3D scanning in reasonable times, to further develop the reconstruction and image analysis software of the scanner, and to further evaluate and develop formulations of polymer gel optimized for their optical properties. The latter will require studies designed to better understand the factors that affect the optical density - dose response of polymer gels. There are significant advantages to the use of this simpler optical method of reading the dose distribution stored by the gel compared to MR imaging, which is the only alternative. The polymer gel - optical scanner system 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. PROPOSED COMMERCIAL APPLICATION: Acceptance testing of approximately 125 new high energy X-ray machines requires the measurement of between 6 and 12 dose distributions, using about 1,200 gels. Quality assurance procedures for the existing 2,500 linear accelerators could require 10,000 polymer-gels. Brachytherapy and experimental applications could account for 2,000 more gels. At $300 per gel, initial annual sales of gels in excess of $3 Million are anticipated. Scanner sales (25 per year at $60,000 each) would add $l.5 Million to this.

该项目旨在开发一种新颖的组织等效凝胶剂量电离辐射，能够产生高度分辨的辐射使用光学的三维剂量分布的准确数据层析成像密度法。剂量反应机制取决于在现场凝胶中生产瑞利散射微粒辐射吸收，其中丙烯酸联合体分散在凝胶中聚合。准直传的吸收和散射通过光学浊度介质产生光的净衰减可以测量并与剂量直接相关的强度。光密度投影的测量方向可用于重建辐射剂量的分布在凝胶中。可以通过空间测量1 Gy的量剂量分辨率<1mm。在第1阶段，凝胶的基本光学特性具有研究了使用单个激光器的原型光学扫描仪构建光束和扫描光电二极管并成功地用于创建准确的2D剂量图。第二阶段的目标是重新设计光学断层扫描设备，以便在合理的情况下执行3D扫描时间，进一步开发重建和图像分析软件扫描仪，并进一步评估和开发聚合物凝胶针对其光学特性进行了优化。后者会需要设计的研究，以更好地了解影响该的因素光学密度 - 聚合物凝胶的剂量反应。有重要的使用这种更简单的光学方法来读取剂量的优势与MR成像相比，凝胶存储的分布是唯一的选择。聚合物凝胶 - 光学扫描仪系统会发现在放射疗法实践中广泛使用，用于3D测量同质和拟人化幻象，确认计算机化治疗计划和质量保证程序。拟议的商业应用：大约125的接受测试新的高能X射线机需要在6和6之间的测量 12剂分布，使用约1200凝胶。质量保证现有2,500个线性加速器的程序可能需要10,000 聚合物凝胶。近距离放射治疗和实验应用可以说明再增加2,000凝胶。凝胶的初始年销售额为300美元预计将超过300万美元。扫描仪销售（每年25个每个$ 60,000）将为此增加50万美元。