Enhancing hepatic microwave ablation (EHMA) - Improving treatment efficacy of liver tumors with patient-specific planning

• Applicants: Professor Dr. Kai Lehmann; Professor Dr. Stefan Niehues; Professor Dr. Tobias Preusser; Dr. Christian Rieder; Professorin Dr. Kristina Ringe
• Subject Area: Nuclear Medicine, Radiotherapy, Radiobiology ; General and Visceral Surgery
• Term: from 2015 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 261433767

In Europe, more than 3 million newly diagnosed cancer diseases are reported per year. More than 50% of the patients tend to get metastasis in the liver. By surgical resection of liver metastases from colorectal carcinoma in particular, notable improvement of the prognosis with 5-year survival of 40 - 60% could be shown. However, regarding prognosis related facts, only about 15 percent of affected patients are eligible for surgical resection. Furthermore, recurrence in the remaining liver in about 70 % of the patient has to be expected. Thus, alternative, parenchyma-sparing, and repeatable alternatives are required for the majority of patients with liver metastases. As a result, radiofrequency ablation (RFA) has become a clinically accepted additional treatment option for liver metastases, although it is limited by size and location of the metastases. Recently, microwave ablation (MWA) has received increasing attention as an alternative to RFA due to the following advantages: (1) Considerably shorter treatment times, (2) larger ablation zones, (3) limited effect of vessel cooling, and (4) no dispersive electrodes are required.In clinical practice, treatment planning for tumor ablation procedures is performed using pre-procedural images, but without software assistance. Thus, the therapeutic outcome depends highly on operator expertise and complexity of the particular case. The research in our project is driven by the hypothesis that simulating the patient-specific outcome of MWA in a treatment-planning software can increase the effectiveness as well as the safety of MWA therapy, and thus can have an important clinical implication. In the first project phase, we build the initial version of a treatment planning system for MWA that is based on numerical simulation, integrates individual patient anatomy and was evaluated ex vivo and in vivo. The goal of this proposal is to take the next steps towards evaluating these hypotheses. In particular, we will show that: (1) tissue shrinkage has a high impact on the treatment and evaluation of MWA procedures, (2) in contrast to findings in the literature, depending on the type of the MWA hardware, vascular and capillary perfusion can have a great impact on the outcome of MWA, (3) CT postprocessing (perfusion/DEM) improves the monitoring of MWA procedures, and (4) an enhanced patient-specific numerical simulation considering tissue shrinkage, perfusion, and heat-sink effects improves planning of MWA procedures.

• DFG Programme: Research Grants