3D simulation of external beam radiotherapy

Radiation therapy treatment is a very demanding cancer treatment process. The aim of the treatment is to cure or to limit the disease using high-energy radiation dose, having as minimum as possible damage on healthy tissues. In order to have the wanted results, the process is composed from several steps that are highly depended to each other. One could separate them into three different categories; the treatment planning and evaluation, the planning verification before and after treatment and finally the treatment itself. This work is a contribution in the chain of the radiotherapy process from the medical software application point of view. In principle the 3-Dimensional digital patient data are used instead of the physical patient, in order to perform the geometric planning (3D-Simulation), and partly the evaluation steps of the radiation therapy process. This thesis introduces the fully 3D definition of volumetric structures, offering higher degree of freedom to the clinicians for investigating the 3D information of the digital volumes. Also presents the semi-automatic segmentation of the spine, which is an essential tool used daily for the extraction of the spine volume. Main advantages of the methods are the increased efficiency and the improved time rates during volume segmentation. An interesting part of this work is the compensation of breathing artifacts as they are recorded and reconstructed on the surfaces of the acquired computed tomography medical volumes. This kind of artifacts is a source for potential errors during treatment planning and treatment evaluation. In this work we present a method for eliminating these inaccuracies and thus improving the treatment outcome. Further more using as basis the volume rendering pipe-line of the 3D-Simulation system reconstruction techniques have been established, to display anatomical volumes from specific body regions with sensitive structures. These methods require the minimum user interaction. Finally this thesis deals with a very essential issue related to the treatment planning verification. This is by presenting methods for the 3D visualization of the dose distribution in relation to the standard patient anatomy and the segmented anatomical structures

S.: An accurate 3d segmentation method of the spinal canal applied to CT data. In: Bildverarbeitung fur die Medizin

Abstract. With the modern treatment planning techniques the accurate definition of the target volume as well as the organs at risk is a crucial step for the treatment outcome. One of the key organs that must be protected during the irradiation treatment is the spinal cord. Nowadays, high resolution computed tomography (CT) data are required to perform accurate treatment planning, and there is the demand for quick but accurate segmentation tools. In this work we present a very simple approach that can accurately extract the spinal canal in three dimensions (3D) from CT images. The user must define only the starting point for the algorithm and the rest of the process is performed automatically. The core of our method is a boundary-tracing algorithm combined with linear interpolation techniques in the longitudinal (z) direction.

Boundary Representation of Anatomical Features

In Simulationen für Bestrahlungstherapieplanung und andere medizinischen und bioingenieur wissenschaftlichen Anwendungen hat man traditionellerweise die anatomischen Eigenschaften mittels volumenbasierten Techniken angezeigt -- Trotzdem, während der Bedarf an Behandlung, Organsimulation und Erzeugung von Prothese präziser wird, reicht es nicht die Menge und die Position von solchen Features zu wissen, sondern auch Detailstufen, die vergleichbar sind zu denjenigen, die man für ingenieurwissenschaftliche Techniken verwendet (finite element analysis, rapid prototyping, Herstellung, usw.) -- Dieser Artikel präsentiert Bemühungen und Ergebnisse in der Anwendung von computerunterstützten geometrischen Algorithmen auf biomedizinischen Applikationen, wobei diese Algorithmen sich ursprünglich auf die Begrenzung von Formen gerichtet haben, die auf Planarmustern von anatomischen Zielregionen basierte

Advanced Applications of Volume Visualization Methods in Medicine

This chapter summarizes the state-of-the-art application of techniques developed over the recent years for visualising volumetric medical data acquired by modern medical imaging modalities such as CT, MRA, MRI, Nuclear Medicine, 3D-Ultrasound, Laser Confocal Microscopy etc. Although all of the modalities provide "slices of the body", significant differences exist between the image content of each modality. The focus of the Report is less in explaining algorithms and rendering techniques, but rather to point out their applicability, benefits, and potential in the medical environment. In the first part, fundamentals of medical image processing and methods for all steps of the volume visualisation pipeline from data preprocessing to object display are reviewed, with special emphasis on data structures, segmentation, and surface- and volume-based rendering. Furthermore, volume registration, intelligent visualisation, intervention rehearsal, and aspects of image quality are discussed. In the second part, applications are illustrated from the areas of craniofacial surgery, traumatology, neurosurgery, radiotherapy, and medical education. Further, some new applications of volumetric methods are presented: 3D ultrasound, laser confocal datasets, and 3D-reconstruction of cardiological datasets, i.e. vessels as well as ventricles. These new volumetric methods are currently under development but due to their enormous application potential they are expected to be clinically accepted within the next years

Advanced applications of volume visualization methods in medicine

This State of The Art Report summarises the application of techniques developed over the recent years for visualising volumetric medical data acquired by modern medical imaging modalities such as CT, MRA, MRI, Nuclear Medicine, 3D-Ultrasound, Laser Confocal Microscopy etc. Although all of the modalities provide "slices of the body", significant differences exist between the image content of each modality. The focus of the Report is be less in explaining algorithms and rendering techniques, but rather to point out their applicability, benefits, and potential in the medical environment. In the first part, fundamentals of medical image processing and methods for all steps of the volume visualisation pipeline from data preprocessing to object display are reviewed, with special emphasis on data structures, segmentation, and surface- and volume-based rendering. Furthermore, volume registration, intelligent visualisation, intervention rehearsal, and aspects of image quality are discussed. In the second part, applications are illustrated from the areas of craniofacial surgery, traumatology, neurosurgery, radiotherapy, and medical education. Further, some new applications of volumetric methods are presented: 3D ultrasound, laser confocal datasets, and 3D-reconstruction of cardiological datasets, i.e. vessels as well as ventricles. These new volumetric methods are currently under development but due to their enormous application potential they are expected to be clinically accepted within the next years

EXOMIO virtual simulation ; oropharynx , prostate and breast cancers

Simulators are medical devices used in the oncology clinics to perform the simulation for the external beam radiotherapy treatment. Unlikely for a clinic to obtain a real Simulator is a high investment in terms of money, space and personnel. The alternative here can be a Virtual Simulator (VS). The CT simulators are system-software that can perform the simulation process using the Computed Tomography (CT) data set of the patient, including the external patient's skin landmarks, instead of the physical patient. In this paper we present a new high performance CT based virtual simulation system running on a low cost widely available PC hardware - EXOMIO. The implemented high-end visualization techniques allow the users to simulate every function of the real simulator including the mechanical component movements, radiation beam projection and fluoroscopy. Further more this virtual simulation concept provides the physicians with ergonomic volume definition and navigation tools. Our clinical experience is described using three patient examples: Neck cancer, prostate cancer and breast cancer. The advantages of virtual simulation system over classical simulation are stated and its clinical effectiveness is emphasized