CT-guided radiofrequency ablation for lung cancer.

Recently, percutaneous radiofrequency (RF) ablation has been increasingly performed as a local treatment for lung malignancies. In RF ablation, the application of radiofrequency agitates ions in the tissues surrounding the electrode, causing them to fluctuate at high speed, and this generates frictional heat. The generated heat coagulates the tissues. Puncture is carried out under computed tomography (CT) guidance in the same manner as that for needle biopsy. In animal studies, it was speculated that air functioned as an insulator and that the heat did not damage normal surrounding lung parenchyma to any great extent, because lung is filled with air. An experimental VX2 tumor in rabbits was well controlled by RF ablation. Since the clinical use of RF ablation for lung malignancies was first reported in 2000, many series have been published. The patients reported in these studies were not candidates for surgical treatment, either because of poor cardiopulmonary function and comorbidities, or because they refused surgery. With RF ablation, complete necrosis can be expected for tumors with a diameter of 3 cm or less. Palliative RF ablation may be indicated for large tumors. The most frequent complication associated with puncture was pneumothorax, with a frequency higher for RF ablation compared with that for needle biopsy. The initial results have been promising, but we await future reports for long-term results.