Changes in Respiratory Function over Time after Radiofrequency Ablation for Lung Tumors

To investigate changes in respiratory function after radiofrequency ablation for lung tumors.

Data from 21 patients who underwent respiratory function tests before radiofrequency ablation, during the early period (20-57 days; median, 34 days), and during the late period (104-692 days; median, 264 days) after lung radiofrequency ablation were retrospectively assessed. The index tumors included 10 primary lung cancers and 11 metastatic lung tumors, with a median tumor size of 12 mm (range, 4-21). Seventeen patients had a history of smoking, and the median Brinkman Index was 500 (range, 0-1,200). Percentage changes in vital capacity and forced expiratory volume in 1 s relative to baseline values were calculated and compared using the Wilcoxon signed-rank test. Risk factors for decreased vital capacity and forced expiratory volume in 1 s were examined by univariate analysis using the Mann-Whitney U test.

All radiofrequency ablation procedures were completed as planned. Vital capacity and forced expiratory volume in 1 s showed significant decreases to 98.0% (p = 0.048) and 96.8% (p = 0.048), respectively, in the early period, but recovered to 100.2% (p = 0.89) and 98.1% (p = 0.28), respectively, in the late period. Forced expiratory volume in 1 s decreased significantly in the early period among patients with a Brinkman Index >500 (98.9% for Brinkman Index ≤500 and 91.2% for Brinkman Index >500, p = 0.002).

Respiratory function decreased temporarily within 2 months after lung radiofrequency ablation but recovered several months thereafter. Caution is needed because forced expiratory volume in 1 s tends to decrease in the early period after radiofrequency ablation in patients with a smoking history and a Brinkman Index >500.