Microwave ablation is a minimally-invasive option for removing liver tumours, which has been tried out at University of California's San Diego (UCSD) Medical Center and its Cancer Centre.

'A liver tumour can be removed in many ways,' said Marquis Hart, transplant surgeon at the medical center.

'Simply put, we zap and destroy liver tumours with heat derived from microwave energy. This is an important alternative, especially since the majority of liver cancers cannot be partially removed and not all patients are transplant candidates.'

Liver cancer is on the rise in the US, linked closely with the epidemic of hepatitis and other conditions causing cirrhosis, a degenerative disease of the liver.

Current treatment options for liver cancer include transplantation, partial surgical removal of the liver, chemotherapy, radiation, or ablation - the destruction of abnormal tissue with heat from radiofrequency waves, high frequency ultrasound, freezing, or alcohol injection. Now, microwave technology removes the tumour with intense heat.

To perform the procedure, Hart accesses the tumour through the skin, or through a small laparoscopic port or open incision.

With ultrasound guidance or a computed tomography (CT) scan, the tumour is located and then pierced with a thin antenna which emits microwaves. This energy spins the water molecules in the tumour producing friction which causes heat.

Temperatures above 60 degrees Celsius (140 degrees Fahrenheit) cause cellular death, usually within 10 minutes.

Microwave ablation has promising potential in the treatment of lung, kidney, and bone cancer, said a UCSD release.