Percutaneous radiofrequency ablation of lung neoplasms: Initial therapeutic response

PURPOSE: To evaluate the feasibility, safety, and initial therapeutic effect of radiofrequency (RF) ablation in the treatment of unresectable malignant lung tumors. MATERIALS AND METHODS: Fifty-four lung neoplasms in 31 patients were treated with RF ablation. Thirteen tumors were primary lung cancers and 41 were pulmonary metastases. Tumor sizes ranged from 0.7 to 6.0 cm, with a mean size of 2.7 +/- 1.3 cm. After the RF electrode was placed in the tumor with computed tomographic (CT) fluoroscopic guidance, RF energy was applied. Initial therapeutic response was evaluated by F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and contrast-enhanced CT. The disappearance of FDG uptake on PET images and tumor enhancement on CT images were considered to indicate complete tumor necrosis. Complete necrosis rates were evaluated according to tumor size and type (primary or secondary lung neoplasm). RESULTS: RF ablation was technically successful in all lesions. Complete necrosis was achieved in 32 of the 54 tumors (59%) after initial RF session. There was a significant difference in the rate of complete tumor necrosis between tumors 3 cm or less and tumors larger than 3 cm (69% vs. 39%; P <.05). Tumor type did not influence complete necrosis rates. Lung abscesses developed in two patients with large tumors. CONCLUSION: Lung RF ablation is a feasible, relatively safe, and promising treatment for unresectable lung neoplasms. Tumor size is an important factor in achieving complete tumor necrosis.