Lesion prediction relies on the online extraction and alignment of the heat sources induced by the RFA needle during RFA execution. Since the 3D model of the liver is built offline from the pre-interventional CT data, the heat source (i.e., the needle) is registered with this precomputed model during the RFA procedure.
Fast (below 2min) image-based registration algorithm provides accurate (< 5mm) registration, that fulfils the required clinical accuracy.
Real-time RFA simulation uses GPU accelerated fast solvers to predict heat transfer and cell death evolution, which can be nonlinear due to temperature dependencies, and therefore computationally expensive.
The clinical protocol of RFA comprises a sequence of steps and procedures followed by the IR at each of the clinical trial centres. The RFA Guardian is installed locally on a server in the intervention room. The RFA Guardian supports the IR at each step of the RFA, the software is optimized to suit the standard clinical workflow. Every step is documented in a checklist/case report form that covers all details of the patient condition and RFA procedure.
Sample ablation protocol for 5-cm ablation (RITA Medical, Boston Scientific):