Invited talk by Dr. Tingying Peng

Dr. Tingying Peng Institute of Biomedical Engineering (IBME) at University of Oxford, UK. Date: Tuesday, 13 September 2011 Time: 1.30pm Location: MI 03.13.010

Mathematical modelling of Radio frequency ablation of malignant liver tumours

Abstract:

Thermal ablation of a tumour in the liver with Radio Frequency energy can be accomplished by using a probe inserted into the tissue under the guidance of medical imaging. However, this minimally invasive treatment still has major drawbacks: the exact extension of the necrosis zone is currently difficult to plan or monitor and assessment of the results during or straight after the procedure is very limited. As a result, IMPPACT project, funded by European Commission, aims to develop a patient-specific intervention planning system for clinicians to use to optimize the heating protocol in advance of the treatment.

A bottleneck on the way towards such a patient specific planning tool is our limited understanding of electrical-thermo processes during tissue heating and ultimately, tissue death as the result of that heating. The established bio-heat equation assumes the blood cooling to be a homogeneous heat sink, ignorant of blood flow direction. This oversimplified estimation of blood cooling effects can greatly affect the prediction of tissue temperature and thus the lesion zone after the intervention, especially for highly blood-perfused organs such as the liver. In this talk I will describe a novel two-equation coupled bio-heat equation to model the heat exchange between blood flow and its surrounding liver tissue, by considering the vasculature as a porous medium. The model simulation is able to recover the experimentally observed different intrahepatic cooling on the thermal ablation zones: hepatic veins showed a focal indentation whereas portal veins showed broad flatterning of the lesion zones. Moreover, the implementation of this two-equation coupled model in the pig liver geometry shows quantitative agreements between model predicted lesion zone and that measured through histological examination. Some preliminary human studies will also be presented and discussed alongside plans to translate this modelling into clinical practice.

Short Bio:

Tingying Peng is a postdoctoral researcher at Institute of Biomedical Engineering (IBME) at University of Oxford, where she is working on the EU research project, Image-based Multi-scale Physiological Planning for Ablation Cancer Treatment (IMPPACT). She was awarded her PhD degree in Engineering Science by the University of Oxford in 2009 and her PhD thesis is titled "Signal processing methods for the analysis of cerebral blood flow and metabolism", supervised by Dr. Stephen Payne and Prof. Yiannis Ventikos.

Tingying has a broad research background in biomedical engineering. She has worked medical signal/image processing, data analysis, system identification, mathematical modelling and computational simulation in several world-leading research institutes including the University of Oxford, Peking University and Harvard Medical School. Her research has been published in several leading academic journals in the biomedical field as well having been presented in a number of international conferences.