Comparison of the secondary cancer risk after conventional and intensity-modulated radiotherapy using an animal model

使用动物模型比较常规放疗和调强放疗后的继发癌症风险

• 批准号: 256898620
• 负责人: Dr. Jens Fleckenstein
• 金额: --
• 依托单位: Universitätsklinikum Freiburg
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/256898620?language=en
• 关键词: Comparison; secondary; cancer; risk; after

External-beam radiotherapy is an integral part of current multimodal cancer therapies. Over the past decades, radiation-induced adverse effects were consequently reduced by improving target coverage with higher conformality, which was enabled by the advent of intensity-modulated Radiotherapy (IMRT). However, to achieve a high degree of conformality, the technique exposes a significant volume of the body with low radiation doses, which is often referred to as 'low-dose bath'. It has been hypothesized that IMRT may therefore increase secondary cancers, which is controversially discussed as there are to date no to little experimental (standardized) data on the incidence of secondary cancers in low-dose areas. Our group has commissioned a Micro-CT as small-animal irradiation device and, as a first step of this proposal, we now aim to establish a Monte-Carlo-based planning system to enable small animal IMRT. We will then define a fixed target volume in tumor-permissive rats, which will be irradiated either conventionally (via opposing fields) or via rotations in an intensity-modulated fashion. The primary objective is comparing induced tumor incidences in high-, low- and no-dose areas. A secondary goal is to establish overall and cancer-free survival rates. The project displays the first standardized comparative assessment of cancer incidences after conventional and modulated radiotherapy and will provide data for a re-assessment of risks associated with the technique.

外照射是目前多模式癌症治疗中不可或缺的一部分。在过去的几十年里，由于调强放射治疗(IMRT)的出现，以更高的一致性提高了靶区覆盖率，从而减少了辐射引起的不良反应。然而，为了达到高度的一致性，该技术以较低的辐射剂量暴露出相当大的身体体积，这通常被称为“低剂量沐浴”。因此，调强放射治疗可能会增加继发性癌症，这一假设引起了争议，因为到目前为止，还没有或几乎没有关于低剂量地区继发性癌症发病率的实验(标准化)数据。我们团队已经委托了一台Micro-CT作为小动物照射设备，作为这项提议的第一步，我们现在的目标是建立一个基于蒙特卡洛的规划系统，以实现小动物调强放疗。然后，我们将在允许肿瘤的大鼠中定义一个固定的靶体积，它将以常规方式(通过相反的野)或通过旋转以强度调制的方式进行照射。主要目标是比较高剂量、低剂量和无剂量地区的诱发肿瘤发生率。次要目标是建立总体和无癌症存活率。该项目展示了对常规和调制放射治疗后癌症发病率的第一次标准化比较评估，并将为重新评估与该技术相关的风险提供数据。