Radiofrequency Ablation (RFA)

Radiofrequency ablation (often abbreviated RFA) is a minimally invasive method for destroying tumors, including liver metastases of GIST. It involves insertion of a needle electrode into the tumor to heat and kill the tumor cells with radiofrequency energy. Imaging such as CT or ultrasound is used to guide the needle placement. Once the needle is in place, metal tines are deployed from the hollow core of the needle that penetrate and envelope the tumor. Radio waves are then transmitted to the needle tip and though the tines. These radio waves generate heat that "cooks" the tumor.

Radiofrequency ablation is not the same as ionizing radiation therapy used for tumors of the breast or prostate, etc. Radiofrequency ablation uses low-frequency radio waves that generate localized heat, not the destructive ionizing radiation given off by radioactive elements.

Because it does not require a large incision, it enables the patient to recover from the procedure much more quickly than abdominal surgery. RFA is especially appropriate for patients who cannot tolerate surgery.

In treating GIST, RFA is applicable to relatively small liver tumors that are not close to blood vessels or ducts in the liver, as long as there are not too many tumors. It may also be useful in cases where a resistant clone is growing within a non-liver GIST (the “nodule-within-a-mass” phenomenon), while the remainder of the tumor is still controlled with imatinib or another drug.

Excellent descriptions and photos of radiofrequency ablation are available at this link:

RadiologyInfo.org

Additional links describing the procedure include these:

• National Institutes of Health
• Mayo Clinic
• Mass General Hospital 
• Cleveland Clinic
• University of California at Davis Medical Center

Managing Liver Lesions: role of adjunctive Radiofequency Ablation
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