A controller, an external electrode and a probe to be inserted into a tissue volume. One end of the probe is terminated by one or more electrodes and the other end is connected to a load cell. The electrode end of the probe is inserted into a volume of adipose tissue to be treated. Intermittently different and low power RF energy is applied between the external electrode and the electrodes of the probe. Monitoring of the impedance between the external electrode and the probe electrodes enables probe guidance. Monitoring of the impedance between the probe electrodes helps characterize the aggregate state of the treated tissue volume and treatment end-point.
