Growth of cryoablation lesion (green, opaque) inside ice-ball (273K isotherm; cyan, translucent) for tumour ablation in a kidney (grey, translucent). Four needles (grey, opaque) are present. Colour-scale slice through computational domain shows variation in temperature in a cross-section from freezing to body temperature.

Model Development And Numerical Simulation

Model development and numerical simulation are the responsibility of the partners from NUMA Engineering Services Ltd. and The University of Oxford. A modelling platform is being developed that is able to predict the ablation zone, for an individual patient, created during radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation therapies. The aim of this is to improve the ability of interventional radiologists to visualise and plan these treatments, comparing them side by side and improving patient outcomes.

The platform is being built around Elmer the open source finite element multi-physics simulation software. There will be support for the specification of new medical hardware as it is developed, and an interface for external simulation software to provide flexibility. For example, this would allow the existing automatic image segmentation and mesh generation tools to be used, but the ablation zone could be computed using improved modelling software. The platform would also be a testbed for new hardware providing quantitative comparisons between applicators from different manufacturers or between different modalities.

Novel research is being conducted to ensure that the platform is both accurate and robust. Detailed clinical data is being collected with which to validate all of the models and ensure that useful predictions can be made. Additionally, when considering a patient specific simulation there are inevitably certain physiological parameters that cannot be measured, and represent uncertainty in the model that we are working to quantify. This information will guide decisions about the safety margin required during ablative therapy and the viability of specific treatment options.