What is radiofrequency ablation (RFA), and how does it work?
RFA is a technique for generating heat in living tissues through alternating electrical currents. The alternating currents result in agitation of ions and frictional heat, which can result in coagulation necrosis of tissue. This technology has been applied to the treatment of many conditions, including liver, kidney, bone, and lung tumors. A metal probe can be placed percutaneously in the tumor using US or CT guidance and is attached to the RF machine. RFA results in tumor death via thermal energy.
What characteristics of hepatic lesions are considered treatable by RFA? What are the characteristics of renal lesions treatable by RFA?
RFA is best done when there are three or fewer tumors to treat in the liver or kidney. Liver or kidney tumors 3 cm or smaller in size respond best to RFA. Larger tumors can be treated, but results are not usually as good.
What is the major CT and MR imaging characteristic of a lesion successfully treated with RFA?
MRI or CT is performed with intravenous contrast material 1 month after RFA to evaluate the success of the treatment. The intravenous contrast material causes tumors to enhance if they are still viable. If a tumor is successfully treated, it is necrotic and will not enhance after contrast material administration on CT or MRI.
How are patients followed after RFA procedures?
Patients usually have CT or MRI performed 1 month after the procedure and then at 3- to 6-month intervals as determined by the tumor type and institutional protocols.
What subset of patients with renal lesions is best treated with RFA?
Currently, RFA is usually reserved for patients who are not surgical candidates because of comorbid medical conditions or renal insufficiency or who have refused surgical resection of the kidney mass. As more long-term studies of RFA in renal masses are performed, more patients may be considered as candidates for this therapy.
What are complications of RFA?
Complications after RFA include bleeding, infection, injury to the organ being treated, and injury to surrounding organs including bowel.