Real-Time Temperature Monitoring in Liver During Magnetite Nanoparticle-Enhanced Microwave Ablation With Fiber Bragg Grating Sensors: Ex Vivo Analysis

In this paper, we present the design and experiments of a fiber Bragg grating (FBG) sensing network for nanoparticle-enhanced microwave ablation (MWA). MWA is an emerging minimally invasive treatment for cancer care, making use of a miniaturized applicator; it is possible to deliver a cytotoxic thermal treatment in situ with high spatial confinement. Cells' death is nearly instantaneous at 60 °C. The use of magnetite nanoparticles enhances the amount of ablated tissue, and reshapes the thermal distribution during the treatment. In order to measure the thermal maps (temperature as a function of space and time) instantaneously and in situ, a set of three arrays of five FBG sensors has been designed, mapping the thermal distribution of the tissue and estimating the ablated tissue in real time. Experiments carried out with different nanoparticle densities show that the extension of the ablated region is the highest for a density of 5 mg/mL. The results are displayed in the form of thermal maps, over the ablation plane.