Development of a system for treatment planning of ocular tumours taking into account the nhomogeneities of the surface dose rate distribution of the radiation sources

钌-106眼斑近距离放射治疗是一种成功治疗眼部肿瘤的有效方法。然而，斑块的表面剂量率分布并不均匀。所谓的热点和冷点使计划复杂化，而且在临床上没有详细测量这些不均匀性的系统。此外，缺乏软件来支持治疗计划和可视化三维剂量分布，以便能够精确评估肿瘤控制率的依从性和对风险结构的影响。在这个项目中，一个系统，以支持治疗计划近距离治疗眼内肿瘤是开发。在该系统中，眼斑表面剂量分布的不均匀性将被纳入计划中，以实现维持肿瘤控制率的目标，同时为风险结构提供最佳的保护。将粒子物理学的方法和专业知识与临床医学物理学的经验相结合，将克服开发该系统的挑战。为了测量斑块的表面剂量率分布，正在开发一种可以集成到日常临床实践中的仪器。测量是在空气中进行的，这种设置防止了闪烁体前面的一个集成空气轴产生切伦科夫辐射。以前用于测量表面剂量分布的系统的定位不确定度被最小化，并且设置的复杂性保持在低水平。该仪器将用于研究涂抹器制造商指定的测量点足以表示表面剂量分布的程度。与设备的发展平行，将创建用于眼肿瘤近距离治疗的3D治疗计划的软件。在这个项目中，要建立一个模型，在这个模型中，将施药器的表面同心分成单独的部分，并计算一个部分的标准剂量分布。然后，各段的加权应允许对表面剂量率分布的不均匀性进行蒙特卡罗模拟。使用所开发的仪器测量的剂量值的实施将成为可能。此外，神经网络的发展应允许在没有蒙特卡罗模拟的情况下产生剂量分布，以便能够估计对风险结构的第一次影响。随后，进一步的神经网络将用于通过改变眼斑的定位和方向来开发优化治疗的可能性。该项目将允许在三维眼模型中可视化近距离治疗的剂量分布，以便对治疗的成功和挑战进行精确评估。

Brachytherapy with Ruthenium-106 eye plaques is an effective method for successfully treating ocular tumours. However, the surface dose rate distribution of the plaques is not homogeneous. So-called hot and cold spots complicate planning, and there is no system for detailed measurement of these inhomogeneities in the clinic. Furthermore, there is a lack of software to support therapy planning and to visualise the three-dimensional dose distribution in order to be able to precisely assess compliance with the tumour control rate and the influence on risk structures. In this project, a system to support therapy planning for brachytherapy of intraocular tumours is to be developed. In this system, the inhomogeneities of the surface dose profile of the eye plaques are to be included in the planning to achieve the goal of maintaining the tumour control rate while at the same time providing the best possible protection of the risk structures. The challenges of developing this system will be overcome by combining the methods and expertise of particle physics with experience in clinical medical physics. To measure the surface dose rate distribution of the plaques, an apparatus is being developed that can be integrated into daily clinical practice. The measurements are performed in air, and the type of set-up prevents the generation of Cherenkov radiation by an integrated air shaft in front of the scintillator. The positioning uncertainties of previous systems for measuring the surface dose profile are minimised, and the complexity of the set-up is kept low. The apparatus will be used to investigate the extent to which the measuring points specified by the applicator manufacturer are sufficient to represent the surface dose profile. Parallel to the development of the apparatus, software for 3D therapy planning for brachytherapy of ocular tumours is to be created. In this project, a model is to be developed in which the surface of the applicator is divided concentrically into individual segments, and the standard dose distribution of a segment is calculated. The weighting of the segments should then allow the Monte Carlo simulation of the inhomogeneities of the surface dose rate distribution. The implementation of the dose values measured with the developed apparatus will be enabled. Furthermore, the development of neural networks should allow the generation of dose profiles without Monte Carlo simulations in order to be able to estimate the first effects on the risk structures. Subsequently, further neural networks will be used to develop the possibility of optimising the treatment by varying the positioning and orientation of the eye plaque. The programme will allow visualisation of the resulting dose distributions of brachytherapy in a three-dimensional eye model so that a precise assessment of the success of the therapy as well as the challenges can be made.