A medical system for ablating a tissue site with real-time monitoring during an electroporation treatment procedure. A pulse generator generates a pre-treatment (PT) test signal having a frequency of at least 1 MHz prior to the treatment procedure and intra-treatment (IT) test signals during the treatment procedure. A treatment control module determines impedance values from the PT test signal and IT test signals and determines a progress of electroporation and an end point of treatment in real-time based on the determined impedance values while the treatment progresses.