Repeat Radiofrequency Ablation for Local Progression of Lung Tumors: Does It Have a Role in Local Tumor Control? Takao Hiraki, MD, Hidefumi Mimura, MD, Hideo Gobara, MD, Yoshifumi Sano, MD, Hiroyasu Fujiwara, MD, Hiroshi Date, MD, and Susumu Kanazawa, MD PURPOSE: To retrospectively evaluate the role of repeat radiofrequency (RF) ablation for local progression of lung tumors in local tumor control. MATERIALS AND METHODS: From June 2001 to February 2007, the authors treated 797 lung tumors (primary lung cancer, n  66; metastatic lung neoplasm, n  731; mean tumor size, 1.7 cm) in 295 patients with RF ablation. After RF ablation, patients were followed-up with contrast-enhanced chest computed tomography at 1, 3, 6, 9, and 12 months and thereafter at 6-month intervals. Local progression was observed in 117 of the 797 lung tumors. Fifty repeat RF ablation sessions were performed for 56 tumors (primary lung cancer, n  9; metastatic lung neoplasm, n  47; mean tumor size, 2.7 cm) in 46 patients (33 men, 13 women; mean age, 59.6 years). Repeat RF ablation was not performed for the remaining 61 locally progressing tumors because it was not presumed to provide survival benefit. For all 797 tumors, the overall primary and secondary technique effectiveness rates (TERs) after the first RF ablation were compared with each other. To determine the risk factors for local control with repeat RF ablation, multiple variables were analyzed. Next, local control with repeat RF ablation was evaluated for tumors with and tumors without risk factors. RESULTS: The overall secondary TERs were significantly higher than the overall primary TERs (P < .00001). Tumor size of at least 2 cm at the first RF ablation (P  .045) and contact with bronchi (P  .045) or vessels (P  .048) were risk factors for local control with repeat RF ablation. The secondary TERs after the first RF ablation were 94% at 1 year, 68% at 2 years, and 55% at 3 years for tumors without risk factors and 60% at 1 year and 40% at 2 years for tumors with at least one risk factor. Among the 50 repeat RF ablation sessions, pneumothorax occurred in 13 sessions (26%), one of which necessitated chest tube placement; pleural effusion occurred in nine sessions (18%), all of which resolved spontaneously. Thermal injury of the brachial plexus occurred after one session. CONCLUSIONS: Repeat RF ablation improved the overall local control outcomes. In particular, it offered an opportunity to salvage tumors that had no risk factors but nevertheless progressed locally after the first RF ablation. Conversely, tumors with risk factors were not controlled sufficiently even after repeating the procedure. J Vasc Interv Radiol 2008; 19:706 –711 Abbreviations: RF = radiofrequency, TER = technique effectiveness rate RADIOFREQUENCY (RF) ablation has received considerable attention as a local therapy for hepatic tumors (1– 4). The favorable outcomes of RF ab- lation for hepatic tumors have facili- tated the application of this technique to neoplasms in other organs, includ- ing the lungs. The local control out- comes of RF ablation for lung tumors, however, appear somewhat inferior to those for hepatic tumors. Several stud- ies with a mean follow-up of at least 1 year showed that the primary local control rate of lung tumors was ap- proximately 60%–70% (5–8). Lung cancer, whether primary or secondary, may show microscopic extension around the tumor (9,10). Thus, abla- tion of the surrounding parenchyma together with the tumor appears im- portant for complete treatment. How- From the Departments of Radiology (T.H., H.M., H.G., H.F., S.K.), and Cancer and Thoracic Surgery (Y.S., H.D.), Okayama University Medical School, 2-5-1 Shikatacho, Okayama 700-8558, Japan. Received August 6, 2007; final revision received November 29, 2007; accepted December 1, 2007. Address correspon- dence to T.H.; E-mail: takaoh@tc4.so-net.ne.jp None of the authors have identified a conflict of interest. © SIR, 2008 DOI: 10.1016/j.jvir.2007.12.441 706