CT-guided Pulmonary Radiofrequency Ablation

Abstract

Editor: We read with interest the article by Dr Simon and colleagues (1), in the April 2007 issue of Radiology, on the results of computed tomographically (CT)guided radiofrequency (RF) ablation in 153 patients, which included 116 cases of primary lung cancer that was medically inoperable or for which the patient refused surgery. The local control and complications associated with this procedure were well documented by these experienced investigators. However, their discussion cites only outcomes following older conventional radiation therapy delivery and failed to cite recent data obtained by using stereotactic radiation therapy (SRT) from groups in Japan, North America, and Europe. The reported 3-year local control rates after RF ablation were 57% and 25% for T1 and T2 tumors, respectively, which are no better than the results of high-dose conventional radiation therapy (reviewed in Qiao et al [2]; see table 4 of that article). However, far superior local control rates on the order of 90% have been obtained in stage I non–small cell lung cancer (NSCLC) with SRT, which allows the delivery of biologically equivalent doses in excess of 100 Gy in one to five fractions on an outpatient basis (3). The noninvasive SRT technique results in a less than 3% incidence of toxicity exceeding grade 2 and has no adverse effect on overall quality of life and no treatment-related mortality (4–8). In contrast, RF treatment was complicated by a pneumothorax in 28% of patients and required chest tube insertion in 10% of patients and had a procedure-specific 30-daymortality rate of 2.6%. Similar morbidity data were reported in other reports of RF ablation (9–11), with toxicity requiring hospitalization in approximately 10% of patients owing to pneumoor hematothorax, massive hemoptysis, bronchopleural fistulas, or abscesses. Discussions on nonsurgical treatment options in stage I NSCLC must consider high-precision SRT, particularly as the available data suggests that RF ablation appears to be associated with significantly more mortality and morbidity. A randomized trial in patients with inoperable disease comparing these two options is eagerly awaited.