**6.4 Ablation zone prediction**

The application of IRE lacks the possibility of ablation validation as, in contrast to thermal ablation, the ablation zone cannot be monitored in real time. Therefore, the clinician must fully rely on the ablation zone prediction from the manufacturer, which is based on mathematical and ex vivo models. However, ultrasound elastography has shown potential to distinct ablated tissue from normal liver parenchyma with respect to tissue stiffness, which peaked 4 hours post-ablation [53]. Based on the ultrasound characteristics at 2 hours post-ablation in combination with histopathology findings, Bhutiani et al. [54] have shown the mismatch of current models with in vivo-generated ablation volumes in porcine liver and spleen.

#### **6.5 From theory to practice**

The placement of needles according to the defined trajectories is seen as a challenging task, especially for medical professionals who are not versatile in the art of *Computer Assistance in the Minimally Invasive Ablation Treatment of Pancreatic Cancer DOI: http://dx.doi.org/10.5772/intechopen.93226*

needle insertion. Therefore, navigation solutions are of great interest to empower these clinicians to conduct safe procedures with IRE in the pancreas. Needle navigation by means of software and hardware guidance is best applicable to improve the spatial accuracy and to spare structures at risk. Especially the aiming device has shown its value in the reduction of needle bending for inexperienced users. Further improvement toward parallel insertion of the electrodes is required since this is, next to the interelectrode spacing, an important aspect to achieve a homogeneous ablation volume.
