A PRECISELY targeted electric "zap" has been used to kill tumours in a new cancer treatment being pioneered at Melbourne's Alfred hospital.

This month Thomas Monaghan, 81, of Bacchus Marsh, became the first person in the world to have a kidney tumour treated by the technique, dubbed the "NanoKnife".

Professor Ken Thompson (right) with patient Thomas Monaghan. Credit:Simon Schluter

Instead of risky surgery, imprecise radiotherapy or debilitating chemotherapy, doctors insert two thin needles into the tumour and arc 90 pulses of high-voltage electric current across it over 45 seconds.

The pulses kill the tumour cells and then the body's natural processes replace the dead cells with healthy tissue.