University of California San Francisco

Microwave Ablation

While some liver tumors can be removed surgically, the majority are inoperable and must be treated by alternative means.  One such method is ablation (tissue destruction), a surgical procedure traditionally performed using a number of techniques including:

  • RFA (Radiofrequency Ablation)
  • Laser destruction
  • Freezing (cyrosurgery)
  • Alcohol injection

A new technology, microwave ablation (MWA), destroys liver tumors using heat generated by microwave energy.  With microwave ablation, the surgeon inserts a small laparoscopic port or open incision to access the tumor. A CT scan or ultrasonic guidance is used to pinpoint the exact location of the tumor. A thin antenna, which emits microwaves, is then inserted into the tumor. The probe produces intense heat that ablates (destroys) tumor tissue, often within 10 minutes.

Microwave ablation has a number advantages when compared to traditional RFA, a standard method for ablating liver tumors, These include:

  • Speed - Microwave ablation (MWA) is faster than RFA, destroying tumors more efficiently, and reducing the time patients remain under general anesthesia.
  • Simultaneous Tumor Ablation - With MWA, surgeons can ablate multiple liver tumors at the same time.
  • Larger Tumor Size - MWA can ablate larger tumors than are possible with RFA.

UCSF is among a select group of cancer centers to offer microwave ablation (MWA) to treat inoperable liver tumors. These include hepatocellular carcinoma (primary liver cancer), a disease associated with cirrhosis and hepatitis B and C, and metastatic liver tumors. Metastatic or secondary liver cancer results through the spread of cancer from another organ in the body,

Because the liver has two blood supplies and a ready store of growth factors, it is a fertile site for liver metastases, liver tumors  originating elsewhere in the body. Abdominal cancers, and especially colorectal cancer, frequently metastasize to the liver.