Gel dosimetry for brachytherapy dose delivery validation

现代放射治疗通过技术的发展而进步，以更好地**塑造肿瘤体积的辐射剂量，同时将对周围**正常组织的不良剂量影响降至最低。在近距离放射治疗(希腊语：近距离治疗)中，放射源被置于机器人控制下的肿瘤内。在放射源附近放置剂量探测器会影响邻近区域的剂量。因此，近距离放射治疗中的剂量传递验证通常**基于非常简单的几何形状的质量保证，这些几何形状不像**患者治疗期间**临床遇到的那样复杂。**一种有前景的剂量测量技术是凝胶剂量测量，它基于成像**特殊的凝胶系统，在辐射时会发生变化。这些变化可以用我们实验室可用的各种**技术进行成像，并提供剂量的空间分布。凝胶模拟组织，因此测量的剂量与患者的剂量相对应。因此，**剂量测量更准确，我们可以在治疗开始前验证给定**患者的计划交付。**我们建议：i)测试当前凝胶配方在**近距离放射治疗剂量学中的有效性和缺点，并创建、表征和测试专为**近距离放射治疗应用设计的新配方；ii)开发专门针对近距离放射治疗剂量输送**的标准方案和幻影；以及，iii)开发软件以评估和比较**凝胶测量的剂量与使用传统工具的测量和计划剂量传递。**在其他使用X射线机的放射治疗传递中，计划传递的测试每天进行**，但还不能用于近距离放射治疗。我们将是第一个为近距离放射治疗开发患者**特定剂量传递验证的公司。

Modern radiation therapy has advanced through the development of techniques to better**shape radiation dose to tumour volumes while minimizing adverse dose effects to surrounding**normal tissue. In brachytherapy (Greek: near therapy) radiation sources are placed into the**tumour under robotic control. Placing a dose detector near the radiation source affects dose**in adjacent regions. For this reason, dose delivery validation in brachytherapy is usually**based on quality assurance of very simple geometries that are not as complex as those**clinically encountered during patient treatments.**A promising technique for dose measurement is gel dosimetry which is based on imaging**special gel systems which change when irradiated. The changes can be imaged with various**techniques available to our laboratory and provide the spatial distribution of the dose. The**gels mimic tissue and so the dose measured corresponds to the dose to a patient. As a result,**dose measurement is more accurate and we can validate a planned delivery for a given**patient before treatment starts.**We propose to: i) test current gel formulations for their effectiveness and shortcomings in**brachytherapy dosimetry and create, characterize and test new formulations designed**specifically for brachytherapy applications; ii) develop standard protocols and phantoms**specific to brachytherapy dose delivery; and, iii) develop software to evaluate and compare**gel-measured doses to measurements using conventional tools and to planned dose delivery.**Testing of planned delivery is performed daily in other radiation therapy delivery with x-ray**machines but is not yet available for brachytherapy. We will be the first to develop patient**specific dose delivery validation for brachytherapy.