In this context, several external methods have been explored for accurate temperature measurements during thermal ablation treatments: external thermocouples, computed tomography (CT)-imaging, ultrasound, and magnetic resonance imaging (MRI). CT-thermometry is noninvasive but has the dual disadvantages of low reproducibility and resolution and also requires precise calibration. Ultrasound-based techniques, while being noninvasive and giving better spatial resolution, can, however, be distorted by physiological movements. For example, MRI-thermometry can lead to measurement errors and is more expensive compared with other thermal monitoring technologies.7,8 Finally, even though thermocouples are often invasive and have poor metrological properties (slow response and heat sink effect) to date, they are the most used approach of RFA instrumentations.9 Indeed, in the last generation of commercial RFA devices, temperature measurement is typically provided by means of 1 to 5 mini-thermocouple sensors mounted on the device tip(s), or by measuring the tissue impedance, which allows an indirect temperature estimation. In this way, temperature is directly or indirectly measured only in the region reached by the RF electrodes. Moreover, the temperature gradient versus the distance from the electrodes is estimated by means of the tissue thermal impedance and/or by the expertise of the operator. This ensures maintaining appropriate error margin with consequent enlargement of the thermally treated tissue region.