Hideo Gobara MD, Presenter: Nothing to Disclose

Takao Hiraki MD, Abstract Co-Author: Nothing to Disclose

Hidefumi Mimura MD, Abstract Co-Author: Nothing to Disclose

Kentaro Shibamoto MD, Abstract Co-Author: Nothing to Disclose

Yuko Soda, Abstract Co-Author: Nothing to Disclose

Susumu Kanazawa MD, Abstract Co-Author: Nothing to Disclose

Ryotaro Kishi MD, Abstract Co-Author: Nothing to Disclose

Mayu Uka, Abstract Co-Author: Nothing to Disclose

Yoshihisa Masaoka, Abstract Co-Author: Nothing to Disclose

Sosuke Harada, Abstract Co-Author: Nothing to Disclose

The purpose of the study was to retrospectively evaluate the risk factors for severe inflammatory reaction after percutaneous radiofrequency (RF) ablation of lung tumors.

This study included 348 RF ablation sessions performed for 568 tumors in 233 patients (141 men, 92 women; mean age, 63.5 years). We defined severe inflammatory reaction as development of fever >38 degree with C-reactive protein (CRP) >10.0 mg/dl. Under CT fluoroscopy guidance, all ablation sessions were percutaneously done using an expandable multitined electrode (LeVeen, Boston Scientific, Natick MA). We reviewed medical chart and CT images, and recorded many patients’ and procedural values. Numerous values were evaluated using chi square for univariate analyses and Cox regression for multivariate analyses.

Severe inflammatory reaction was developed after 52 of 348 RF sessions (14.9%). A mean CRP was 18.4 ± 6.7 mg/dl, 10.1-35.0 mg/dl). Univariate analysis indicated the following as risk factors for severe inflammatory reaction: primary lung cancer (n = 57, p =.008), presence of emphysema (n = 44, p =.003), tumor with a diameter of >2 cm (n = 82, p =.001), electrode array diameter of ≥3.5 cm (n = 32, p =.0001), maximum power output of > 80W (n = 116, p =.005), and chest tube placement (n = 36, p =.0009). Age (p =.18), sex (p =.54), tumor number treated in the same session (p=.56), minimum distance between the tumor and parietal pleura of <5 mm (p =.14), total ablation time (p =.64), and presence of pneumothorax (p =.20) were not significant risk factors (p =.35). Multivariate analysis for all the 348 sessions determined that electrode array diameter of ≥3.5 cm (hazard ratio [HR], 3.12; 95% confidence interval [95% CI], 1.35-7.20; p =.008) and presence of emphysema (HR, 2.29, 95% CI, 1.04-5.05, p =.04) were assessed as independent risk factors for severe inflammatory reaction.

The use of electrode array diameter of ≥3.5 cm, and presence of emphysema were independent technical risk factors for severe inflammatory reaction after RF ablation of lung tumors.

To know risk factors for severe inflammatory reaction is useful for the patient care after the treatment, especially for a patient with poor general condition.

Gobara, H, Hiraki, T, Mimura, H, Shibamoto, K, Soda, Y, Kanazawa, S, Kishi, R, Uka, M, Masaoka, Y, Harada, S, Risk Factors for Severe Inflammatory Reaction after Percutaneous Radiofrequency Ablation of Lung Tumor.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9014464.html