Abstract:
Radiofrequency ablation (RFA) represents a significant minimally invasive tumor therapy, wherein a needle electrode heats and destroys cancerous tissue with a safety margin while minimizing damage to healthy surrounding tissue. Despite its clinical application, predicting the precise outcome of RFA interventions remains challenging, and success is typically confirmed only through follow-up examinations. To address this, computer-supported prediction models are highly desirable. This intervention's planning is critically dependent not only on patient anatomy, as derived from radiological images, but also significantly on physiological factors. Consequently, accurate prediction necessitates a sophisticated computational model that solves complex, three-dimensional systems of partial differential equations. For practical clinical application, such biomechanical models demand rigorous validation to ensure their predictive accuracy and gain acceptance within the medical community. This thesis specifically addresses this validation challenge using liver tumor radiofrequency ablation as an example. Recognizing the inherently interdisciplinary nature of this research, a novel concept for validating simulation results through visual comparison with findings from an animal study is proposed and tackled. Individual contributions of this thesis include the development of a visualization tool for multi-volume raycasting (volumetric rendering) , a mathematical model for the radiofrequency ablation process that also predicts effects of needle misplacement, and a data acquisition protocol for the animal study. This protocol is designed to facilitate the use of state-of-the-art image processing tools, enabling the creation of a virtual liver model suitable for the validation task. Furthermore, the study presents initial results comparing the intervention's outcome, as observed in histologies, with its radiological equivalent. The cumulative effort yields an interdisciplinary validation tool chain designed to address the complex research questions posed. The bibliography also references "TrueGrid", indicating its relevance as a meshing tool used in the broader context of computational modeling and finite element analysis within this biomechanical field.
