RF ablation kills tumours using a small needle that's inserted into the targeted area under ultrasound or CT guidance. RF energy is sent through the needle and "cooks" the surrounding tissue in a similar manner to the way that a microwave oven cooks food. The technique is a versatile, painless and minimally invasive alternative to the surgical removal of tumours or lengthy treatments like radiotherapy.

"RF ablation can be used in cases where surgical resection poses too great of a risk to the patient [and therefore] increases the treatable patient population," noted Stephanie LaBelle, an analyst at MRG.

Despite these advantages, RF ablation is still not that widely used and has yet to gain widespread acceptance among the clinical community. As such, many patients who could benefit from RF ablation are made to undergo potentially dangerous operations.

As the technique is tried in new situations, however, its benefits are becoming increasingly clear. Earlier this year, for example, medicalphysicsweb reported on a US study which showed that RF ablation used to treat early-stage, inoperable lung cancer resulted in outcomes that were equal to or better than those achieved through external-beam therapy (EBT).

"In our study, RF ablation produced meaningful results in terms of both survival and tumour control," noted Damian E Dupuy, director of tumour ablation at Rhode Island Hospital (Providence, RI) and professor of diagnostic imaging at Brown Medical School in Providence. "The best two-year survival rate for early-stage lung cancer using EBT is 51%, compared to 57% with ablation."

He continued: "Conventional EBT involves 33 treatments over a six-week period and can often lead to side-effects including radiation pneumonia and the permanent loss of lung tissue. RF ablation is performed in a single day as an outpatient procedure, is minimally invasive and has few side-effects."

Contact Amy Krohn (akrohn@mrg.net) for further details on MRG's report US Markets for Nonvascular Interventional Radiology Devices 2008.

• See also RF ablation: feel the heat on medicalphysicsweb.